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drh75897232000-05-29 14:26:00 +00001/*
drhb19a2bc2001-09-16 00:13:26 +00002** 2001 September 15
drh75897232000-05-29 14:26:00 +00003**
drhb19a2bc2001-09-16 00:13:26 +00004** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
drh75897232000-05-29 14:26:00 +00006**
drhb19a2bc2001-09-16 00:13:26 +00007** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
drh75897232000-05-29 14:26:00 +000010**
11*************************************************************************
12** Internal interface definitions for SQLite.
13**
drh665de472003-03-31 13:36:09 +000014** @(#) $Id: sqliteInt.h,v 1.169 2003/03/31 13:36:09 drh Exp $
drh75897232000-05-29 14:26:00 +000015*/
drh58f391b2002-11-20 11:55:18 +000016#include "config.h"
drh75897232000-05-29 14:26:00 +000017#include "sqlite.h"
drhbeae3192001-09-22 18:12:08 +000018#include "hash.h"
drh75897232000-05-29 14:26:00 +000019#include "vdbe.h"
20#include "parse.h"
drhbe0072d2001-09-13 14:46:09 +000021#include "btree.h"
drh75897232000-05-29 14:26:00 +000022#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <assert.h>
26
drh967e8b72000-06-21 13:59:10 +000027/*
drha1b351a2001-09-14 16:42:12 +000028** The maximum number of in-memory pages to use for the main database
29** table and for temporary tables.
30*/
drh603240c2002-03-05 01:11:12 +000031#define MAX_PAGES 2000
32#define TEMP_PAGES 500
drha1b351a2001-09-14 16:42:12 +000033
34/*
drh0bd1f4e2002-06-06 18:54:39 +000035** If the following macro is set to 1, then NULL values are considered
36** distinct for the SELECT DISTINCT statement and for UNION or EXCEPT
37** compound queries. No other SQL database engine (among those tested)
38** works this way except for OCELOT. But the SQL92 spec implies that
39** this is how things should work.
40**
41** If the following macro is set to 0, then NULLs are indistinct for
42** SELECT DISTINCT and for UNION.
43*/
44#define NULL_ALWAYS_DISTINCT 0
45
46/*
47** If the following macro is set to 1, then NULL values are considered
48** distinct when determining whether or not two entries are the same
49** in a UNIQUE index. This is the way PostgreSQL, Oracle, DB2, MySQL,
50** OCELOT, and Firebird all work. The SQL92 spec explicitly says this
51** is the way things are suppose to work.
52**
53** If the following macro is set to 0, the NULLs are indistinct for
54** a UNIQUE index. In this mode, you can only have a single NULL entry
55** for a column declared UNIQUE. This is the way Informix and SQL Server
56** work.
57*/
58#define NULL_DISTINCT_FOR_UNIQUE 1
59
60/*
drh665de472003-03-31 13:36:09 +000061** The maximum number of attached databases. This must be at least 2
62** in order to support the main database file (0) and the file used to
63** hold temporary tables (1). And it must be less than 256 because the
64** an unsigned character is used to stored the database index.
65*/
66#define MAX_ATTACHED 10
67
68/*
drh5a2c2c22001-11-21 02:21:11 +000069** Integers of known sizes. These typedefs might change for architectures
70** where the sizes very. Preprocessor macros are available so that the
71** types can be conveniently redefined at compile-type. Like this:
72**
73** cc '-DUINTPTR_TYPE=long long int' ...
drh41a2b482001-01-20 19:52:49 +000074*/
drh5a2c2c22001-11-21 02:21:11 +000075#ifndef UINT32_TYPE
76# define UINT32_TYPE unsigned int
77#endif
78#ifndef UINT16_TYPE
79# define UINT16_TYPE unsigned short int
80#endif
81#ifndef UINT8_TYPE
82# define UINT8_TYPE unsigned char
83#endif
84#ifndef INTPTR_TYPE
drh58f391b2002-11-20 11:55:18 +000085# if SQLITE_PTR_SZ==4
86# define INTPTR_TYPE int
87# else
88# define INTPTR_TYPE long long
89# endif
drh5a2c2c22001-11-21 02:21:11 +000090#endif
91typedef UINT32_TYPE u32; /* 4-byte unsigned integer */
92typedef UINT16_TYPE u16; /* 2-byte unsigned integer */
93typedef UINT8_TYPE u8; /* 1-byte unsigned integer */
94typedef INTPTR_TYPE ptr; /* Big enough to hold a pointer */
95typedef unsigned INTPTR_TYPE uptr; /* Big enough to hold a pointer */
96
97/*
98** This macro casts a pointer to an integer. Useful for doing
99** pointer arithmetic.
100*/
101#define Addr(X) ((uptr)X)
drh41a2b482001-01-20 19:52:49 +0000102
103/*
drh872ff862001-09-15 14:43:39 +0000104** The maximum number of bytes of data that can be put into a single
drh80ff32f2001-11-04 18:32:46 +0000105** row of a single table. The upper bound on this limit is 16777215
106** bytes (or 16MB-1). We have arbitrarily set the limit to just 1MB
107** here because the overflow page chain is inefficient for really big
108** records and we want to discourage people from thinking that
109** multi-megabyte records are OK. If your needs are different, you can
110** change this define and recompile to increase or decrease the record
111** size.
drh872ff862001-09-15 14:43:39 +0000112*/
drh80ff32f2001-11-04 18:32:46 +0000113#define MAX_BYTES_PER_ROW 1048576
drh872ff862001-09-15 14:43:39 +0000114
115/*
drh967e8b72000-06-21 13:59:10 +0000116** If memory allocation problems are found, recompile with
117**
118** -DMEMORY_DEBUG=1
119**
120** to enable some sanity checking on malloc() and free(). To
121** check for memory leaks, recompile with
122**
123** -DMEMORY_DEBUG=2
124**
125** and a line of text will be written to standard error for
126** each malloc() and free(). This output can be analyzed
127** by an AWK script to determine if there are any leaks.
128*/
drhdcc581c2000-05-30 13:44:19 +0000129#ifdef MEMORY_DEBUG
drh8c1238a2003-01-02 14:43:55 +0000130# define sqliteMalloc(X) sqliteMalloc_(X,1,__FILE__,__LINE__)
131# define sqliteMallocRaw(X) sqliteMalloc_(X,0,__FILE__,__LINE__)
drhdcc581c2000-05-30 13:44:19 +0000132# define sqliteFree(X) sqliteFree_(X,__FILE__,__LINE__)
133# define sqliteRealloc(X,Y) sqliteRealloc_(X,Y,__FILE__,__LINE__)
drh6e142f52000-06-08 13:36:40 +0000134# define sqliteStrDup(X) sqliteStrDup_(X,__FILE__,__LINE__)
135# define sqliteStrNDup(X,Y) sqliteStrNDup_(X,Y,__FILE__,__LINE__)
drhc3c2fc92000-05-31 22:58:39 +0000136 void sqliteStrRealloc(char**);
137#else
138# define sqliteStrRealloc(X)
drhdcc581c2000-05-30 13:44:19 +0000139#endif
140
drh75897232000-05-29 14:26:00 +0000141/*
drhdaffd0e2001-04-11 14:28:42 +0000142** This variable gets set if malloc() ever fails. After it gets set,
143** the SQLite library shuts down permanently.
144*/
145extern int sqlite_malloc_failed;
146
147/*
drh6e142f52000-06-08 13:36:40 +0000148** The following global variables are used for testing and debugging
drh8c82b352000-12-10 18:23:50 +0000149** only. They only work if MEMORY_DEBUG is defined.
drh6e142f52000-06-08 13:36:40 +0000150*/
151#ifdef MEMORY_DEBUG
drh8c82b352000-12-10 18:23:50 +0000152extern int sqlite_nMalloc; /* Number of sqliteMalloc() calls */
153extern int sqlite_nFree; /* Number of sqliteFree() calls */
154extern int sqlite_iMallocFail; /* Fail sqliteMalloc() after this many calls */
drh6e142f52000-06-08 13:36:40 +0000155#endif
156
157/*
drh75897232000-05-29 14:26:00 +0000158** Name of the master database table. The master database table
159** is a special table that holds the names and attributes of all
160** user tables and indices.
161*/
drhe0bc4042002-06-25 01:09:11 +0000162#define MASTER_NAME "sqlite_master"
163#define TEMP_MASTER_NAME "sqlite_temp_master"
drh75897232000-05-29 14:26:00 +0000164
165/*
drhed6c8672003-01-12 18:02:16 +0000166** The name of the schema table.
167*/
168#define SCHEMA_TABLE(x) (x?TEMP_MASTER_NAME:MASTER_NAME)
169
170/*
drh75897232000-05-29 14:26:00 +0000171** A convenience macro that returns the number of elements in
172** an array.
173*/
174#define ArraySize(X) (sizeof(X)/sizeof(X[0]))
175
176/*
177** Forward references to structures
178*/
drh7020f652000-06-03 18:06:52 +0000179typedef struct Column Column;
drh75897232000-05-29 14:26:00 +0000180typedef struct Table Table;
181typedef struct Index Index;
182typedef struct Instruction Instruction;
183typedef struct Expr Expr;
184typedef struct ExprList ExprList;
185typedef struct Parse Parse;
186typedef struct Token Token;
187typedef struct IdList IdList;
drhad3cab52002-05-24 02:04:32 +0000188typedef struct SrcList SrcList;
drh75897232000-05-29 14:26:00 +0000189typedef struct WhereInfo WhereInfo;
drh6b563442001-11-07 16:48:26 +0000190typedef struct WhereLevel WhereLevel;
drh9bb61fe2000-06-05 16:01:39 +0000191typedef struct Select Select;
drh22827922000-06-06 17:27:05 +0000192typedef struct AggExpr AggExpr;
drh0bce8352002-02-28 00:41:10 +0000193typedef struct FuncDef FuncDef;
danielk1977c3f9bad2002-05-15 08:30:12 +0000194typedef struct Trigger Trigger;
195typedef struct TriggerStep TriggerStep;
196typedef struct TriggerStack TriggerStack;
drhc2eef3b2002-08-31 18:53:06 +0000197typedef struct FKey FKey;
drh001bbcb2003-03-19 03:14:00 +0000198typedef struct Db Db;
199
200/*
201** Each database file to be accessed by the system is an instance
202** of the following structure. There are normally two of these structures
203** in the sqlite.aDb[] array. aDb[0] is the main database file and
204** aDb[1] is the database file used to hold temporary tables. But
205** additional databases may be attached to the engine.
206*/
207struct Db {
208 char *zName; /* Name of this database */
209 Btree *pBt; /* The B*Tree structure for this database file */
210 int schema_cookie; /* Database schema version number for this file */
drhd24cc422003-03-27 12:51:24 +0000211 Hash tblHash; /* All tables indexed by name */
212 Hash idxHash; /* All (named) indices indexed by name */
213 Hash trigHash; /* All triggers indexed by name */
214 Hash aFKey; /* Foreign keys indexed by to-table */
drh001bbcb2003-03-19 03:14:00 +0000215 u8 inTrans; /* True if a transaction is underway for this backend */
drhd24cc422003-03-27 12:51:24 +0000216 u16 flags; /* Flags associated with this database */
drh001bbcb2003-03-19 03:14:00 +0000217};
drh75897232000-05-29 14:26:00 +0000218
219/*
drhc9b84a12002-06-20 11:36:48 +0000220** Each database is an instance of the following structure.
221**
222** The sqlite.file_format is initialized by the database file
223** and helps determines how the data in the database file is
224** represented. This field allows newer versions of the library
225** to read and write older databases. The various file formats
226** are as follows:
227**
228** file_format==1 Version 2.1.0.
229** file_format==2 Version 2.2.0. Add support for INTEGER PRIMARY KEY.
drh491791a2002-07-18 00:34:09 +0000230** file_format==3 Version 2.6.0. Fix empty-string index bug.
231** file_format==4 Version 2.7.0. Add support for separate numeric and
drhc9b84a12002-06-20 11:36:48 +0000232** text datatypes.
drh75897232000-05-29 14:26:00 +0000233*/
234struct sqlite {
drh001bbcb2003-03-19 03:14:00 +0000235 int nDb; /* Number of backends currently in use */
236 Db *aDb; /* All backends */
237 Db aDbStatic[2]; /* Static space for the 2 default backends */
drh5e00f6c2001-09-13 13:46:56 +0000238 int flags; /* Miscellanous flags. See below */
drh973b6e32003-02-12 14:09:42 +0000239 u8 file_format; /* What file format version is this database? */
240 u8 safety_level; /* How aggressive at synching data to disk */
drh94e92032003-02-16 22:21:32 +0000241 u8 want_to_close; /* Close after all VDBEs are deallocated */
drh001bbcb2003-03-19 03:14:00 +0000242 int next_cookie; /* Next value of aDb[0].schema_cookie */
drhcd61c282002-03-06 22:01:34 +0000243 int cache_size; /* Number of pages to use in the cache */
drh5e00f6c2001-09-13 13:46:56 +0000244 int nTable; /* Number of tables in the database */
245 void *pBusyArg; /* 1st Argument to the busy callback */
drh353f57e2000-08-02 12:26:28 +0000246 int (*xBusyCallback)(void *,const char*,int); /* The busy callback */
drh0bce8352002-02-28 00:41:10 +0000247 Hash aFunc; /* All functions that can be in SQL exprs */
drhaf9ff332002-01-16 21:00:27 +0000248 int lastRowid; /* ROWID of most recent insert */
drh5cf8e8c2002-02-19 22:42:05 +0000249 int priorNewRowid; /* Last randomly generated ROWID */
drh1c928532002-01-31 15:54:21 +0000250 int onError; /* Default conflict algorithm */
drh247be432002-05-10 05:44:55 +0000251 int magic; /* Magic number for detect library misuse */
drhc8d30ac2002-04-12 10:08:59 +0000252 int nChange; /* Number of rows changed */
drh326dce72003-01-29 14:06:07 +0000253 struct Vdbe *pVdbe; /* List of active virtual machines */
drh18de4822003-01-16 16:28:53 +0000254#ifndef SQLITE_OMIT_TRACE
255 void (*xTrace)(void*,const char*); /* Trace function */
256 void *pTraceArg; /* Argument to the trace function */
257#endif
drhed6c8672003-01-12 18:02:16 +0000258#ifndef SQLITE_OMIT_AUTHORIZATION
259 int (*xAuth)(void*,int,const char*,const char*); /* Access Auth function */
260 void *pAuthArg; /* 1st argument to the access auth function */
261#endif
drh75897232000-05-29 14:26:00 +0000262};
263
264/*
drh812d7a22003-03-27 13:50:00 +0000265** The following are the indices of in sqlite.aDb[] of the main database
266** file and the file used to store TEMP tables.
267*/
268#define DB_TMP 0
269#define DB_MAIN 1
270
271/*
drh967e8b72000-06-21 13:59:10 +0000272** Possible values for the sqlite.flags.
drh75897232000-05-29 14:26:00 +0000273*/
drh5e00f6c2001-09-13 13:46:56 +0000274#define SQLITE_VdbeTrace 0x00000001 /* True to trace VDBE execution */
275#define SQLITE_Initialized 0x00000002 /* True after initialization */
276#define SQLITE_Interrupt 0x00000004 /* Cancel current operation */
277#define SQLITE_InTrans 0x00000008 /* True if in a transaction */
278#define SQLITE_InternChanges 0x00000010 /* Uncommitted Hash table changes */
drh382c0242001-10-06 16:33:02 +0000279#define SQLITE_FullColNames 0x00000020 /* Show full column names on SELECT */
drh1bee3d72001-10-15 00:44:35 +0000280#define SQLITE_CountRows 0x00000040 /* Count rows changed by INSERT, */
281 /* DELETE, or UPDATE and return */
282 /* the count using a callback. */
drh6a535342001-10-19 16:44:56 +0000283#define SQLITE_NullCallback 0x00000080 /* Invoke the callback once if the */
284 /* result set is empty */
drhc3a64ba2001-11-22 00:01:27 +0000285#define SQLITE_ResultDetails 0x00000100 /* Details added to result set */
drh417be792002-03-03 18:59:40 +0000286#define SQLITE_UnresetViews 0x00000200 /* True if one or more views have */
287 /* defined column names */
drh5080aaa2002-07-11 12:18:16 +0000288#define SQLITE_ReportTypes 0x00000400 /* Include information on datatypes */
289 /* in 4th argument of callback */
drh58b95762000-06-02 01:17:37 +0000290
291/*
drh247be432002-05-10 05:44:55 +0000292** Possible values for the sqlite.magic field.
293** The numbers are obtained at random and have no special meaning, other
294** than being distinct from one another.
295*/
296#define SQLITE_MAGIC_OPEN 0xa029a697 /* Database is open */
297#define SQLITE_MAGIC_CLOSED 0x9f3c2d33 /* Database is closed */
298#define SQLITE_MAGIC_BUSY 0xf03b7906 /* Database currently in use */
299#define SQLITE_MAGIC_ERROR 0xb5357930 /* An SQLITE_MISUSE error occurred */
300
301/*
drh0bce8352002-02-28 00:41:10 +0000302** Each SQL function is defined by an instance of the following
303** structure. A pointer to this structure is stored in the sqlite.aFunc
drh8e0a2f92002-02-23 23:45:45 +0000304** hash table. When multiple functions have the same name, the hash table
305** points to a linked list of these structures.
drh28037572000-08-02 13:47:41 +0000306*/
drh0bce8352002-02-28 00:41:10 +0000307struct FuncDef {
drh0bd1f4e2002-06-06 18:54:39 +0000308 void (*xFunc)(sqlite_func*,int,const char**); /* Regular function */
drh56c0e922002-03-12 23:10:04 +0000309 void (*xStep)(sqlite_func*,int,const char**); /* Aggregate function step */
drh1350b032002-02-27 19:00:20 +0000310 void (*xFinalize)(sqlite_func*); /* Aggregate function finializer */
311 int nArg; /* Number of arguments */
drhc9b84a12002-06-20 11:36:48 +0000312 int dataType; /* Datatype of the result */
drh1350b032002-02-27 19:00:20 +0000313 void *pUserData; /* User data parameter */
drh0bce8352002-02-28 00:41:10 +0000314 FuncDef *pNext; /* Next function with same name */
drh8e0a2f92002-02-23 23:45:45 +0000315};
drh28037572000-08-02 13:47:41 +0000316
317/*
drh967e8b72000-06-21 13:59:10 +0000318** information about each column of an SQL table is held in an instance
drh7020f652000-06-03 18:06:52 +0000319** of this structure.
320*/
321struct Column {
drh967e8b72000-06-21 13:59:10 +0000322 char *zName; /* Name of this column */
323 char *zDflt; /* Default value of this column */
drh382c0242001-10-06 16:33:02 +0000324 char *zType; /* Data type for this column */
drh4a324312001-12-21 14:30:42 +0000325 u8 notNull; /* True if there is a NOT NULL constraint */
326 u8 isPrimKey; /* True if this column is an INTEGER PRIMARY KEY */
drh8e2ca022002-06-17 17:07:19 +0000327 u8 sortOrder; /* Some combination of SQLITE_SO_... values */
drh7020f652000-06-03 18:06:52 +0000328};
329
330/*
drh8e2ca022002-06-17 17:07:19 +0000331** The allowed sort orders.
332**
333** The TEXT and NUM values use bits that do not overlap with DESC and ASC.
334** That way the two can be combined into a single number.
335*/
336#define SQLITE_SO_UNK 0 /* Use the default collating type. (SCT_NUM) */
337#define SQLITE_SO_TEXT 2 /* Sort using memcmp() */
338#define SQLITE_SO_NUM 4 /* Sort using sqliteCompare() */
339#define SQLITE_SO_TYPEMASK 6 /* Mask to extract the collating sequence */
340#define SQLITE_SO_ASC 0 /* Sort in ascending order */
341#define SQLITE_SO_DESC 1 /* Sort in descending order */
342#define SQLITE_SO_DIRMASK 1 /* Mask to extract the sort direction */
343
344/*
drh22f70c32002-02-18 01:17:00 +0000345** Each SQL table is represented in memory by an instance of the
346** following structure.
347**
drhd24cc422003-03-27 12:51:24 +0000348** Table.zName is the name of the table. The case of the original
drh22f70c32002-02-18 01:17:00 +0000349** CREATE TABLE statement is stored, but case is not significant for
350** comparisons.
351**
drhd24cc422003-03-27 12:51:24 +0000352** Table.nCol is the number of columns in this table. Table.aCol is a
drh22f70c32002-02-18 01:17:00 +0000353** pointer to an array of Column structures, one for each column.
354**
drhd24cc422003-03-27 12:51:24 +0000355** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
356** the column that is that key. Otherwise Table.iPKey is negative. Note
drh22f70c32002-02-18 01:17:00 +0000357** that the datatype of the PRIMARY KEY must be INTEGER for this field to
358** be set. An INTEGER PRIMARY KEY is used as the rowid for each row of
359** the table. If a table has no INTEGER PRIMARY KEY, then a random rowid
drhd24cc422003-03-27 12:51:24 +0000360** is generated for each row of the table. Table.hasPrimKey is true if
drh22f70c32002-02-18 01:17:00 +0000361** the table has any PRIMARY KEY, INTEGER or otherwise.
362**
drhd24cc422003-03-27 12:51:24 +0000363** Table.tnum is the page number for the root BTree page of the table in the
364** database file. If Table.iDb is the index of the database table backend
365** in sqlite.aDb[]. 0 is for the main database and 1 is for the file that
366** holds temporary tables and indices. If Table.isTransient
drh22f70c32002-02-18 01:17:00 +0000367** is true, then the table is stored in a file that is automatically deleted
drhd24cc422003-03-27 12:51:24 +0000368** when the VDBE cursor to the table is closed. In this case Table.tnum
drh22f70c32002-02-18 01:17:00 +0000369** refers VDBE cursor number that holds the table open, not to the root
370** page number. Transient tables are used to hold the results of a
371** sub-query that appears instead of a real table name in the FROM clause
372** of a SELECT statement.
drh75897232000-05-29 14:26:00 +0000373*/
374struct Table {
drh967e8b72000-06-21 13:59:10 +0000375 char *zName; /* Name of the table */
drh967e8b72000-06-21 13:59:10 +0000376 int nCol; /* Number of columns in this table */
377 Column *aCol; /* Information about each column */
drhc8392582001-12-31 02:48:51 +0000378 int iPKey; /* If not less then 0, use aCol[iPKey] as the primary key */
drh967e8b72000-06-21 13:59:10 +0000379 Index *pIndex; /* List of SQL indexes on this table. */
drh22f70c32002-02-18 01:17:00 +0000380 int tnum; /* Root BTree node for this table (see note above) */
drha76b5df2002-02-23 02:32:10 +0000381 Select *pSelect; /* NULL for tables. Points to definition if a view. */
drh717e6402001-09-27 03:22:32 +0000382 u8 readOnly; /* True if this table should not be written by the user */
drhd24cc422003-03-27 12:51:24 +0000383 u8 iDb; /* Index into sqlite.aDb[] of the backend for this table */
drh22f70c32002-02-18 01:17:00 +0000384 u8 isTransient; /* True if automatically deleted when VDBE finishes */
drh4a324312001-12-21 14:30:42 +0000385 u8 hasPrimKey; /* True if there exists a primary key */
drh9cfcf5d2002-01-29 18:41:24 +0000386 u8 keyConf; /* What to do in case of uniqueness conflict on iPKey */
danielk1977c3f9bad2002-05-15 08:30:12 +0000387 Trigger *pTrigger; /* List of SQL triggers on this table */
drhc2eef3b2002-08-31 18:53:06 +0000388 FKey *pFKey; /* Linked list of all foreign keys in this table */
drh75897232000-05-29 14:26:00 +0000389};
390
391/*
drhc2eef3b2002-08-31 18:53:06 +0000392** Each foreign key constraint is an instance of the following structure.
393**
394** A foreign key is associated with two tables. The "from" table is
395** the table that contains the REFERENCES clause that creates the foreign
396** key. The "to" table is the table that is named in the REFERENCES clause.
397** Consider this example:
398**
399** CREATE TABLE ex1(
400** a INTEGER PRIMARY KEY,
401** b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
402** );
403**
404** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
405**
406** Each REFERENCES clause generates an instance of the following structure
407** which is attached to the from-table. The to-table need not exist when
408** the from-table is created. The existance of the to-table is not checked
409** until an attempt is made to insert data into the from-table.
410**
411** The sqlite.aFKey hash table stores pointers to to this structure
412** given the name of a to-table. For each to-table, all foreign keys
413** associated with that table are on a linked list using the FKey.pNextTo
414** field.
415*/
416struct FKey {
417 Table *pFrom; /* The table that constains the REFERENCES clause */
418 FKey *pNextFrom; /* Next foreign key in pFrom */
419 char *zTo; /* Name of table that the key points to */
420 FKey *pNextTo; /* Next foreign key that points to zTo */
421 int nCol; /* Number of columns in this key */
422 struct sColMap { /* Mapping of columns in pFrom to columns in zTo */
423 int iFrom; /* Index of column in pFrom */
424 char *zCol; /* Name of column in zTo. If 0 use PRIMARY KEY */
425 } *aCol; /* One entry for each of nCol column s */
426 u8 isDeferred; /* True if constraint checking is deferred till COMMIT */
427 u8 updateConf; /* How to resolve conflicts that occur on UPDATE */
428 u8 deleteConf; /* How to resolve conflicts that occur on DELETE */
429 u8 insertConf; /* How to resolve conflicts that occur on INSERT */
430};
431
432/*
433** SQLite supports many different ways to resolve a contraint
drh22f70c32002-02-18 01:17:00 +0000434** error. ROLLBACK processing means that a constraint violation
drh0bd1f4e2002-06-06 18:54:39 +0000435** causes the operation in process to fail and for the current transaction
drh1c928532002-01-31 15:54:21 +0000436** to be rolled back. ABORT processing means the operation in process
437** fails and any prior changes from that one operation are backed out,
438** but the transaction is not rolled back. FAIL processing means that
439** the operation in progress stops and returns an error code. But prior
440** changes due to the same operation are not backed out and no rollback
441** occurs. IGNORE means that the particular row that caused the constraint
442** error is not inserted or updated. Processing continues and no error
443** is returned. REPLACE means that preexisting database rows that caused
444** a UNIQUE constraint violation are removed so that the new insert or
445** update can proceed. Processing continues and no error is reported.
drhc2eef3b2002-08-31 18:53:06 +0000446**
447** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
448** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
449** same as ROLLBACK for DEFERRED keys. SETNULL means that the foreign
450** key is set to NULL. CASCADE means that a DELETE or UPDATE of the
451** referenced table row is propagated into the row that holds the
452** foreign key.
drh1c928532002-01-31 15:54:21 +0000453**
drh968af522003-02-11 14:55:40 +0000454** The following symbolic values are used to record which type
drh1c928532002-01-31 15:54:21 +0000455** of action to take.
drh9cfcf5d2002-01-29 18:41:24 +0000456*/
drh1c928532002-01-31 15:54:21 +0000457#define OE_None 0 /* There is no constraint to check */
458#define OE_Rollback 1 /* Fail the operation and rollback the transaction */
459#define OE_Abort 2 /* Back out changes but do no rollback transaction */
460#define OE_Fail 3 /* Stop the operation but leave all prior changes */
461#define OE_Ignore 4 /* Ignore the error. Do not do the INSERT or UPDATE */
462#define OE_Replace 5 /* Delete existing record, then do INSERT or UPDATE */
drhc2eef3b2002-08-31 18:53:06 +0000463
464#define OE_Restrict 6 /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
465#define OE_SetNull 7 /* Set the foreign key value to NULL */
466#define OE_SetDflt 8 /* Set the foreign key value to its default */
467#define OE_Cascade 9 /* Cascade the changes */
468
469#define OE_Default 99 /* Do whatever the default action is */
drh9cfcf5d2002-01-29 18:41:24 +0000470
471/*
drh66b89c82000-11-28 20:47:17 +0000472** Each SQL index is represented in memory by an
drh75897232000-05-29 14:26:00 +0000473** instance of the following structure.
drh967e8b72000-06-21 13:59:10 +0000474**
475** The columns of the table that are to be indexed are described
476** by the aiColumn[] field of this structure. For example, suppose
477** we have the following table and index:
478**
479** CREATE TABLE Ex1(c1 int, c2 int, c3 text);
480** CREATE INDEX Ex2 ON Ex1(c3,c1);
481**
482** In the Table structure describing Ex1, nCol==3 because there are
483** three columns in the table. In the Index structure describing
484** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
485** The value of aiColumn is {2, 0}. aiColumn[0]==2 because the
486** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
487** The second column to be indexed (c1) has an index of 0 in
488** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
drh75897232000-05-29 14:26:00 +0000489*/
490struct Index {
drh967e8b72000-06-21 13:59:10 +0000491 char *zName; /* Name of this index */
drh967e8b72000-06-21 13:59:10 +0000492 int nColumn; /* Number of columns in the table used by this index */
493 int *aiColumn; /* Which columns are used by this index. 1st is 0 */
494 Table *pTable; /* The SQL table being indexed */
drhbe0072d2001-09-13 14:46:09 +0000495 int tnum; /* Page containing root of this index in database file */
drh9cfcf5d2002-01-29 18:41:24 +0000496 u8 isUnique; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
drh9cfcf5d2002-01-29 18:41:24 +0000497 u8 onError; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
drh485b39b2002-07-13 03:11:52 +0000498 u8 autoIndex; /* True if is automatically created (ex: by UNIQUE) */
drhd24cc422003-03-27 12:51:24 +0000499 u8 iDb; /* Index in sqlite.aDb[] of where this index is stored */
drh967e8b72000-06-21 13:59:10 +0000500 Index *pNext; /* The next index associated with the same table */
drh75897232000-05-29 14:26:00 +0000501};
502
503/*
504** Each token coming out of the lexer is an instance of
drh4b59ab52002-08-24 18:24:51 +0000505** this structure. Tokens are also used as part of an expression.
drh75897232000-05-29 14:26:00 +0000506*/
507struct Token {
drh80ff32f2001-11-04 18:32:46 +0000508 const char *z; /* Text of the token. Not NULL-terminated! */
drh4b59ab52002-08-24 18:24:51 +0000509 unsigned dyn : 1; /* True for malloced memory, false for static */
drh6977fea2002-10-22 23:38:04 +0000510 unsigned n : 31; /* Number of characters in this token */
drh75897232000-05-29 14:26:00 +0000511};
512
513/*
514** Each node of an expression in the parse tree is an instance
drh22f70c32002-02-18 01:17:00 +0000515** of this structure.
516**
517** Expr.op is the opcode. The integer parser token codes are reused
518** as opcodes here. For example, the parser defines TK_GE to be an integer
519** code representing the ">=" operator. This same integer code is reused
520** to represent the greater-than-or-equal-to operator in the expression
521** tree.
522**
523** Expr.pRight and Expr.pLeft are subexpressions. Expr.pList is a list
524** of argument if the expression is a function.
525**
drh4b59ab52002-08-24 18:24:51 +0000526** Expr.token is the operator token for this node. For some expressions
527** that have subexpressions, Expr.token can be the complete text that gave
528** rise to the Expr. In the latter case, the token is marked as being
529** a compound token.
drh22f70c32002-02-18 01:17:00 +0000530**
531** An expression of the form ID or ID.ID refers to a column in a table.
532** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
533** the integer cursor number of a VDBE cursor pointing to that table and
534** Expr.iColumn is the column number for the specific column. If the
535** expression is used as a result in an aggregate SELECT, then the
536** value is also stored in the Expr.iAgg column in the aggregate so that
537** it can be accessed after all aggregates are computed.
538**
539** If the expression is a function, the Expr.iTable is an integer code
540** representing which function.
541**
542** The Expr.pSelect field points to a SELECT statement. The SELECT might
543** be the right operand of an IN operator. Or, if a scalar SELECT appears
544** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
545** operand.
drh75897232000-05-29 14:26:00 +0000546*/
547struct Expr {
drh1cc093c2002-06-24 22:01:57 +0000548 u8 op; /* Operation performed by this node */
drh8e2ca022002-06-17 17:07:19 +0000549 u8 dataType; /* Either SQLITE_SO_TEXT or SQLITE_SO_NUM */
drh1f162302002-10-27 19:35:33 +0000550 u16 flags; /* Various flags. See below */
drh75897232000-05-29 14:26:00 +0000551 Expr *pLeft, *pRight; /* Left and right subnodes */
drhd99f7062002-06-08 23:25:08 +0000552 ExprList *pList; /* A list of expressions used as function arguments
553 ** or in "<expr> IN (<expr-list)" */
drh75897232000-05-29 14:26:00 +0000554 Token token; /* An operand token */
drh6977fea2002-10-22 23:38:04 +0000555 Token span; /* Complete text of the expression */
drh967e8b72000-06-21 13:59:10 +0000556 int iTable, iColumn; /* When op==TK_COLUMN, then this expr node means the
drh8e2ca022002-06-17 17:07:19 +0000557 ** iColumn-th field of the iTable-th table. */
drh967e8b72000-06-21 13:59:10 +0000558 int iAgg; /* When op==TK_COLUMN and pParse->useAgg==TRUE, pull
559 ** result from the iAgg-th element of the aggregator */
drhd99f7062002-06-08 23:25:08 +0000560 Select *pSelect; /* When the expression is a sub-select. Also the
561 ** right side of "<expr> IN (<select>)" */
drh75897232000-05-29 14:26:00 +0000562};
563
564/*
drh1f162302002-10-27 19:35:33 +0000565** The following are the meanings of bits in the Expr.flags field.
566*/
567#define EP_FromJoin 0x0001 /* Originated in ON or USING clause of a join */
568#define EP_Oracle8Join 0x0002 /* Carries the Oracle8 "(+)" join operator */
569
570/*
571** These macros can be used to test, set, or clear bits in the
572** Expr.flags field.
573*/
574#define ExprHasProperty(E,P) (((E)->flags&(P))==(P))
575#define ExprHasAnyProperty(E,P) (((E)->flags&(P))!=0)
576#define ExprSetProperty(E,P) (E)->flags|=(P)
577#define ExprClearProperty(E,P) (E)->flags&=~(P)
578
579/*
drh75897232000-05-29 14:26:00 +0000580** A list of expressions. Each expression may optionally have a
581** name. An expr/name combination can be used in several ways, such
582** as the list of "expr AS ID" fields following a "SELECT" or in the
583** list of "ID = expr" items in an UPDATE. A list of expressions can
drhad3cab52002-05-24 02:04:32 +0000584** also be used as the argument to a function, in which case the a.zName
drh75897232000-05-29 14:26:00 +0000585** field is not used.
586*/
587struct ExprList {
588 int nExpr; /* Number of expressions on the list */
drh6d4abfb2001-10-22 02:58:08 +0000589 struct ExprList_item {
drh75897232000-05-29 14:26:00 +0000590 Expr *pExpr; /* The list of expressions */
591 char *zName; /* Token associated with this expression */
drh8e2ca022002-06-17 17:07:19 +0000592 u8 sortOrder; /* 1 for DESC or 0 for ASC */
593 u8 isAgg; /* True if this is an aggregate like count(*) */
594 u8 done; /* A flag to indicate when processing is finished */
drh75897232000-05-29 14:26:00 +0000595 } *a; /* One entry for each expression */
596};
597
598/*
drhad3cab52002-05-24 02:04:32 +0000599** An instance of this structure can hold a simple list of identifiers,
600** such as the list "a,b,c" in the following statements:
601**
602** INSERT INTO t(a,b,c) VALUES ...;
603** CREATE INDEX idx ON t(a,b,c);
604** CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
605**
606** The IdList.a.idx field is used when the IdList represents the list of
607** column names after a table name in an INSERT statement. In the statement
608**
609** INSERT INTO t(a,b,c) ...
610**
611** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
drh75897232000-05-29 14:26:00 +0000612*/
613struct IdList {
614 int nId; /* Number of identifiers on the list */
drh6d4abfb2001-10-22 02:58:08 +0000615 struct IdList_item {
drhad3cab52002-05-24 02:04:32 +0000616 char *zName; /* Name of the identifier */
drh967e8b72000-06-21 13:59:10 +0000617 int idx; /* Index in some Table.aCol[] of a column named zName */
drhad3cab52002-05-24 02:04:32 +0000618 } *a;
619};
620
621/*
622** The following structure describes the FROM clause of a SELECT statement.
623** Each table or subquery in the FROM clause is a separate element of
624** the SrcList.a[] array.
drhd24cc422003-03-27 12:51:24 +0000625**
626** With the addition of multiple database support, the following structure
627** can also be used to describe a particular table such as the table that
628** is modified by an INSERT, DELETE, or UPDATE statement. In standard SQL,
629** such a table must be a simple name: ID. But in SQLite, the table can
630** now be identified by a database name, a dot, then the table name: ID.ID.
drhad3cab52002-05-24 02:04:32 +0000631*/
632struct SrcList {
633 int nSrc; /* Number of tables or subqueries in the FROM clause */
634 struct SrcList_item {
drh113088e2003-03-20 01:16:58 +0000635 char *zDatabase; /* Name of database holding this table */
drhad3cab52002-05-24 02:04:32 +0000636 char *zName; /* Name of the table */
637 char *zAlias; /* The "B" part of a "A AS B" phrase. zName is the "A" */
drhdaffd0e2001-04-11 14:28:42 +0000638 Table *pTab; /* An SQL table corresponding to zName */
639 Select *pSelect; /* A SELECT statement used in place of a table name */
drhad3cab52002-05-24 02:04:32 +0000640 int jointype; /* Type of join between this table and the next */
641 Expr *pOn; /* The ON clause of a join */
642 IdList *pUsing; /* The USING clause of a join */
drh113088e2003-03-20 01:16:58 +0000643 } a[1]; /* One entry for each identifier on the list */
drh75897232000-05-29 14:26:00 +0000644};
645
646/*
drh01f3f252002-05-24 16:14:15 +0000647** Permitted values of the SrcList.a.jointype field
648*/
649#define JT_INNER 0x0001 /* Any kind of inner or cross join */
650#define JT_NATURAL 0x0002 /* True for a "natural" join */
drh195e6962002-05-25 00:18:20 +0000651#define JT_LEFT 0x0004 /* Left outer join */
652#define JT_RIGHT 0x0008 /* Right outer join */
drh01f3f252002-05-24 16:14:15 +0000653#define JT_OUTER 0x0010 /* The "OUTER" keyword is present */
654#define JT_ERROR 0x0020 /* unknown or unsupported join type */
655
656/*
drh6b563442001-11-07 16:48:26 +0000657** For each nested loop in a WHERE clause implementation, the WhereInfo
658** structure contains a single instance of this structure. This structure
659** is intended to be private the the where.c module and should not be
660** access or modified by other modules.
661*/
662struct WhereLevel {
663 int iMem; /* Memory cell used by this level */
664 Index *pIdx; /* Index used */
665 int iCur; /* Cursor number used for this index */
drh487ab3c2001-11-08 00:45:21 +0000666 int score; /* How well this indexed scored */
drh6b563442001-11-07 16:48:26 +0000667 int brk; /* Jump here to break out of the loop */
668 int cont; /* Jump here to continue with the next loop cycle */
669 int op, p1, p2; /* Opcode used to terminate the loop */
drhad2d8302002-05-24 20:31:36 +0000670 int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
671 int top; /* First instruction of interior of the loop */
drhd99f7062002-06-08 23:25:08 +0000672 int inOp, inP1, inP2;/* Opcode used to implement an IN operator */
drhc045ec52002-12-04 20:01:06 +0000673 int bRev; /* Do the scan in the reverse direction */
drh6b563442001-11-07 16:48:26 +0000674};
675
676/*
drh75897232000-05-29 14:26:00 +0000677** The WHERE clause processing routine has two halves. The
678** first part does the start of the WHERE loop and the second
679** half does the tail of the WHERE loop. An instance of
680** this structure is returned by the first half and passed
681** into the second half to give some continuity.
682*/
683struct WhereInfo {
684 Parse *pParse;
drhad3cab52002-05-24 02:04:32 +0000685 SrcList *pTabList; /* List of tables in the join */
drh19a775c2000-06-05 18:54:46 +0000686 int iContinue; /* Jump here to continue with next record */
687 int iBreak; /* Jump here to break out of the loop */
688 int base; /* Index of first Open opcode */
drh6b563442001-11-07 16:48:26 +0000689 int nLevel; /* Number of nested loop */
drh832508b2002-03-02 17:04:07 +0000690 int savedNTab; /* Value of pParse->nTab before WhereBegin() */
691 int peakNTab; /* Value of pParse->nTab after WhereBegin() */
drh6b563442001-11-07 16:48:26 +0000692 WhereLevel a[1]; /* Information about each nest loop in the WHERE */
drh75897232000-05-29 14:26:00 +0000693};
694
695/*
drh9bb61fe2000-06-05 16:01:39 +0000696** An instance of the following structure contains all information
697** needed to generate code for a single SELECT statement.
drha76b5df2002-02-23 02:32:10 +0000698**
699** The zSelect field is used when the Select structure must be persistent.
700** Normally, the expression tree points to tokens in the original input
701** string that encodes the select. But if the Select structure must live
702** longer than its input string (for example when it is used to describe
703** a VIEW) we have to make a copy of the input string so that the nodes
704** of the expression tree will have something to point to. zSelect is used
705** to hold that copy.
drhd11d3822002-06-21 23:01:49 +0000706**
707** nLimit is set to -1 if there is no LIMIT clause. nOffset is set to 0.
708** If there is a LIMIT clause, the parser sets nLimit to the value of the
709** limit and nOffset to the value of the offset (or 0 if there is not
710** offset). But later on, nLimit and nOffset become the memory locations
711** in the VDBE that record the limit and offset counters.
drh9bb61fe2000-06-05 16:01:39 +0000712*/
713struct Select {
714 int isDistinct; /* True if the DISTINCT keyword is present */
715 ExprList *pEList; /* The fields of the result */
drhad3cab52002-05-24 02:04:32 +0000716 SrcList *pSrc; /* The FROM clause */
drh9bb61fe2000-06-05 16:01:39 +0000717 Expr *pWhere; /* The WHERE clause */
718 ExprList *pGroupBy; /* The GROUP BY clause */
719 Expr *pHaving; /* The HAVING clause */
720 ExprList *pOrderBy; /* The ORDER BY clause */
drh82c3d632000-06-06 21:56:07 +0000721 int op; /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
drh967e8b72000-06-21 13:59:10 +0000722 Select *pPrior; /* Prior select in a compound select statement */
drh9bbca4c2001-11-06 04:00:18 +0000723 int nLimit, nOffset; /* LIMIT and OFFSET values. -1 means not used */
drha76b5df2002-02-23 02:32:10 +0000724 char *zSelect; /* Complete text of the SELECT command */
drh832508b2002-03-02 17:04:07 +0000725 int base; /* Index of VDBE cursor for left-most FROM table */
drh9bb61fe2000-06-05 16:01:39 +0000726};
727
728/*
drhfef52082000-06-06 01:50:43 +0000729** The results of a select can be distributed in several ways.
730*/
731#define SRT_Callback 1 /* Invoke a callback with each row of result */
732#define SRT_Mem 2 /* Store result in a memory cell */
drh82c3d632000-06-06 21:56:07 +0000733#define SRT_Set 3 /* Store result as unique keys in a table */
734#define SRT_Union 5 /* Store result as keys in a table */
735#define SRT_Except 6 /* Remove result from a UNION table */
drh5974a302000-06-07 14:42:26 +0000736#define SRT_Table 7 /* Store result as data with a unique key */
drh2d0794e2002-03-03 03:03:52 +0000737#define SRT_TempTable 8 /* Store result in a trasient table */
drhd7489c32002-05-27 12:24:48 +0000738#define SRT_Discard 9 /* Do not save the results anywhere */
drhf46f9052002-06-22 02:33:38 +0000739#define SRT_Sorter 10 /* Store results in the sorter */
drh142e30d2002-08-28 03:00:58 +0000740#define SRT_Subroutine 11 /* Call a subroutine to handle results */
drhfef52082000-06-06 01:50:43 +0000741
742/*
drh22827922000-06-06 17:27:05 +0000743** When a SELECT uses aggregate functions (like "count(*)" or "avg(f1)")
744** we have to do some additional analysis of expressions. An instance
745** of the following structure holds information about a single subexpression
746** somewhere in the SELECT statement. An array of these structures holds
747** all the information we need to generate code for aggregate
748** expressions.
749**
750** Note that when analyzing a SELECT containing aggregates, both
751** non-aggregate field variables and aggregate functions are stored
752** in the AggExpr array of the Parser structure.
753**
754** The pExpr field points to an expression that is part of either the
755** field list, the GROUP BY clause, the HAVING clause or the ORDER BY
756** clause. The expression will be freed when those clauses are cleaned
757** up. Do not try to delete the expression attached to AggExpr.pExpr.
758**
759** If AggExpr.pExpr==0, that means the expression is "count(*)".
760*/
761struct AggExpr {
762 int isAgg; /* if TRUE contains an aggregate function */
763 Expr *pExpr; /* The expression */
drh0bce8352002-02-28 00:41:10 +0000764 FuncDef *pFunc; /* Information about the aggregate function */
drh22827922000-06-06 17:27:05 +0000765};
766
767/*
drhf57b3392001-10-08 13:22:32 +0000768** An SQL parser context. A copy of this structure is passed through
769** the parser and down into all the parser action routine in order to
770** carry around information that is global to the entire parse.
drh75897232000-05-29 14:26:00 +0000771*/
772struct Parse {
773 sqlite *db; /* The main database structure */
drh4c504392000-10-16 22:06:40 +0000774 int rc; /* Return code from execution */
drh75897232000-05-29 14:26:00 +0000775 sqlite_callback xCallback; /* The callback function */
776 void *pArg; /* First argument to the callback function */
777 char *zErrMsg; /* An error message */
778 Token sErrToken; /* The token at which the error occurred */
779 Token sFirstToken; /* The first token parsed */
780 Token sLastToken; /* The last token parsed */
drh326dce72003-01-29 14:06:07 +0000781 const char *zTail; /* All SQL text past the last semicolon parsed */
drh75897232000-05-29 14:26:00 +0000782 Table *pNewTable; /* A table being constructed by CREATE TABLE */
783 Vdbe *pVdbe; /* An engine for executing database bytecode */
drh836faa42003-01-11 13:30:57 +0000784 u8 colNamesSet; /* TRUE after OP_ColumnName has been issued to pVdbe */
drhe0bc4042002-06-25 01:09:11 +0000785 u8 explain; /* True if the EXPLAIN flag is found on the query */
786 u8 initFlag; /* True if reparsing CREATE TABLEs */
787 u8 nameClash; /* A permanent table name clashes with temp table name */
788 u8 useAgg; /* If true, extract field values from the aggregator
789 ** while generating expressions. Normally false */
790 u8 schemaVerified; /* True if an OP_VerifySchema has been coded someplace
791 ** other than after an OP_Transaction */
drhd24cc422003-03-27 12:51:24 +0000792 u8 iDb; /* Index of database whose schema is being parsed */
drhb86ccfb2003-01-28 23:13:10 +0000793 u8 useCallback; /* True if callbacks should be used to report results */
drhd78eeee2001-09-13 16:18:53 +0000794 int newTnum; /* Table number to use when reparsing CREATE TABLEs */
drh75897232000-05-29 14:26:00 +0000795 int nErr; /* Number of errors seen */
drh832508b2002-03-02 17:04:07 +0000796 int nTab; /* Number of previously allocated VDBE cursors */
drh19a775c2000-06-05 18:54:46 +0000797 int nMem; /* Number of memory cells used so far */
drhfef52082000-06-06 01:50:43 +0000798 int nSet; /* Number of sets used so far */
drh22827922000-06-06 17:27:05 +0000799 int nAgg; /* Number of aggregate expressions */
800 AggExpr *aAgg; /* An array of aggregate expressions */
drhdc379452002-05-15 12:45:43 +0000801 TriggerStack *trigStack;
drh75897232000-05-29 14:26:00 +0000802};
803
danielk1977d99bc932002-05-16 00:13:12 +0000804/*
805 * Each trigger present in the database schema is stored as an instance of
806 * struct Trigger.
807 *
808 * Pointers to instances of struct Trigger are stored in two ways.
809 * 1. In the "trigHash" hash table (part of the sqlite* that represents the
810 * database). This allows Trigger structures to be retrieved by name.
811 * 2. All triggers associated with a single table form a linked list, using the
drhad3cab52002-05-24 02:04:32 +0000812 * pNext member of struct Trigger. A pointer to the first element of the
813 * linked list is stored as the "pTrigger" member of the associated
814 * struct Table.
danielk1977d99bc932002-05-16 00:13:12 +0000815 *
drhad3cab52002-05-24 02:04:32 +0000816 * The "step_list" member points to the first element of a linked list
817 * containing the SQL statements specified as the trigger program.
danielk1977d99bc932002-05-16 00:13:12 +0000818 *
819 * When a trigger is initially created, the "isCommit" member is set to FALSE.
820 * When a transaction is rolled back, any Trigger structures with "isCommit" set
821 * to FALSE are deleted by the logic in sqliteRollbackInternalChanges(). When
822 * a transaction is commited, the "isCommit" member is set to TRUE for any
823 * Trigger structures for which it is FALSE.
824 *
825 * When a trigger is dropped, using the sqliteDropTrigger() interfaced, it is
drhad3cab52002-05-24 02:04:32 +0000826 * removed from the trigHash hash table and added to the trigDrop hash table.
827 * If the transaction is rolled back, the trigger is re-added into the trigHash
danielk1977d99bc932002-05-16 00:13:12 +0000828 * hash table (and hence the database schema). If the transaction is commited,
829 * then the Trigger structure is deleted permanently.
830 */
danielk1977c3f9bad2002-05-15 08:30:12 +0000831struct Trigger {
drhdc379452002-05-15 12:45:43 +0000832 char *name; /* The name of the trigger */
833 char *table; /* The table or view to which the trigger applies */
drhd24cc422003-03-27 12:51:24 +0000834 int iDb; /* Database containing this trigger */
drhdc379452002-05-15 12:45:43 +0000835 int op; /* One of TK_DELETE, TK_UPDATE, TK_INSERT */
danielk1977d99bc932002-05-16 00:13:12 +0000836 int tr_tm; /* One of TK_BEFORE, TK_AFTER */
drhdc379452002-05-15 12:45:43 +0000837 Expr *pWhen; /* The WHEN clause of the expresion (may be NULL) */
838 IdList *pColumns; /* If this is an UPDATE OF <column-list> trigger,
danielk1977d99bc932002-05-16 00:13:12 +0000839 the <column-list> is stored here */
drhdc379452002-05-15 12:45:43 +0000840 int foreach; /* One of TK_ROW or TK_STATEMENT */
danielk1977c3f9bad2002-05-15 08:30:12 +0000841
drhdc379452002-05-15 12:45:43 +0000842 TriggerStep *step_list; /* Link list of trigger program steps */
drhdc379452002-05-15 12:45:43 +0000843 Trigger *pNext; /* Next trigger associated with the table */
danielk1977c3f9bad2002-05-15 08:30:12 +0000844};
845
danielk1977d99bc932002-05-16 00:13:12 +0000846/*
847 * An instance of struct TriggerStep is used to store a single SQL statement
848 * that is a part of a trigger-program.
849 *
850 * Instances of struct TriggerStep are stored in a singly linked list (linked
851 * using the "pNext" member) referenced by the "step_list" member of the
852 * associated struct Trigger instance. The first element of the linked list is
853 * the first step of the trigger-program.
854 *
855 * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
856 * "SELECT" statement. The meanings of the other members is determined by the
857 * value of "op" as follows:
858 *
859 * (op == TK_INSERT)
860 * orconf -> stores the ON CONFLICT algorithm
861 * pSelect -> If this is an INSERT INTO ... SELECT ... statement, then
862 * this stores a pointer to the SELECT statement. Otherwise NULL.
863 * target -> A token holding the name of the table to insert into.
864 * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
865 * this stores values to be inserted. Otherwise NULL.
866 * pIdList -> If this is an INSERT INTO ... (<column-names>) VALUES ...
drhad3cab52002-05-24 02:04:32 +0000867 * statement, then this stores the column-names to be
868 * inserted into.
danielk1977d99bc932002-05-16 00:13:12 +0000869 *
870 * (op == TK_DELETE)
871 * target -> A token holding the name of the table to delete from.
872 * pWhere -> The WHERE clause of the DELETE statement if one is specified.
873 * Otherwise NULL.
874 *
875 * (op == TK_UPDATE)
876 * target -> A token holding the name of the table to update rows of.
877 * pWhere -> The WHERE clause of the UPDATE statement if one is specified.
878 * Otherwise NULL.
879 * pExprList -> A list of the columns to update and the expressions to update
drhad3cab52002-05-24 02:04:32 +0000880 * them to. See sqliteUpdate() documentation of "pChanges"
881 * argument.
danielk1977d99bc932002-05-16 00:13:12 +0000882 *
883 */
884struct TriggerStep {
885 int op; /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
886 int orconf; /* OE_Rollback etc. */
danielk1977c3f9bad2002-05-15 08:30:12 +0000887
danielk1977d99bc932002-05-16 00:13:12 +0000888 Select *pSelect; /* Valid for SELECT and sometimes
889 INSERT steps (when pExprList == 0) */
890 Token target; /* Valid for DELETE, UPDATE, INSERT steps */
891 Expr *pWhere; /* Valid for DELETE, UPDATE steps */
892 ExprList *pExprList; /* Valid for UPDATE statements and sometimes
893 INSERT steps (when pSelect == 0) */
894 IdList *pIdList; /* Valid for INSERT statements only */
895
896 TriggerStep * pNext; /* Next in the link-list */
897};
898
899/*
900 * An instance of struct TriggerStack stores information required during code
901 * generation of a single trigger program. While the trigger program is being
902 * coded, its associated TriggerStack instance is pointed to by the
903 * "pTriggerStack" member of the Parse structure.
904 *
905 * The pTab member points to the table that triggers are being coded on. The
906 * newIdx member contains the index of the vdbe cursor that points at the temp
907 * table that stores the new.* references. If new.* references are not valid
908 * for the trigger being coded (for example an ON DELETE trigger), then newIdx
909 * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
910 *
911 * The ON CONFLICT policy to be used for the trigger program steps is stored
912 * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
913 * specified for individual triggers steps is used.
914 *
915 * struct TriggerStack has a "pNext" member, to allow linked lists to be
916 * constructed. When coding nested triggers (triggers fired by other triggers)
917 * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
918 * pointer. Once the nested trigger has been coded, the pNext value is restored
919 * to the pTriggerStack member of the Parse stucture and coding of the parent
920 * trigger continues.
921 *
922 * Before a nested trigger is coded, the linked list pointed to by the
923 * pTriggerStack is scanned to ensure that the trigger is not about to be coded
924 * recursively. If this condition is detected, the nested trigger is not coded.
925 */
926struct TriggerStack {
927 Table *pTab; /* Table that triggers are currently being coded on */
928 int newIdx; /* Index of vdbe cursor to "new" temp table */
929 int oldIdx; /* Index of vdbe cursor to "old" temp table */
930 int orconf; /* Current orconf policy */
danielk19776f349032002-06-11 02:25:40 +0000931 int ignoreJump; /* where to jump to for a RAISE(IGNORE) */
danielk1977d99bc932002-05-16 00:13:12 +0000932 Trigger *pTrigger;
933
934 TriggerStack *pNext;
935};
936
937/*
938 * This global flag is set for performance testing of triggers. When it is set
939 * SQLite will perform the overhead of building new and old trigger references
940 * even when no triggers exist
941 */
942extern int always_code_trigger_setup;
danielk1977c3f9bad2002-05-15 08:30:12 +0000943
drh75897232000-05-29 14:26:00 +0000944/*
945** Internal function prototypes
946*/
947int sqliteStrICmp(const char *, const char *);
948int sqliteStrNICmp(const char *, const char *, int);
949int sqliteHashNoCase(const char *, int);
950int sqliteCompare(const char *, const char *);
951int sqliteSortCompare(const char *, const char *);
drh9bbca4c2001-11-06 04:00:18 +0000952void sqliteRealToSortable(double r, char *);
drhdcc581c2000-05-30 13:44:19 +0000953#ifdef MEMORY_DEBUG
drh8c1238a2003-01-02 14:43:55 +0000954 void *sqliteMalloc_(int,int,char*,int);
drhdcc581c2000-05-30 13:44:19 +0000955 void sqliteFree_(void*,char*,int);
956 void *sqliteRealloc_(void*,int,char*,int);
drh6e142f52000-06-08 13:36:40 +0000957 char *sqliteStrDup_(const char*,char*,int);
958 char *sqliteStrNDup_(const char*, int,char*,int);
drhed6c8672003-01-12 18:02:16 +0000959 void sqliteCheckMemory(void*,int);
drhdcc581c2000-05-30 13:44:19 +0000960#else
961 void *sqliteMalloc(int);
drh8c1238a2003-01-02 14:43:55 +0000962 void *sqliteMallocRaw(int);
drhdcc581c2000-05-30 13:44:19 +0000963 void sqliteFree(void*);
964 void *sqliteRealloc(void*,int);
drh6e142f52000-06-08 13:36:40 +0000965 char *sqliteStrDup(const char*);
966 char *sqliteStrNDup(const char*, int);
drhed6c8672003-01-12 18:02:16 +0000967# define sqliteCheckMemory(a,b)
drhdcc581c2000-05-30 13:44:19 +0000968#endif
drh483750b2003-01-29 18:46:51 +0000969char *sqliteMPrintf(const char *,...);
drh75897232000-05-29 14:26:00 +0000970void sqliteSetString(char **, const char *, ...);
971void sqliteSetNString(char **, ...);
drhda93d232003-03-31 02:12:46 +0000972void sqliteErrorMsg(Parse*, const char*, ...);
drh982cef72000-05-30 16:27:03 +0000973void sqliteDequote(char*);
drh17f71932002-02-21 12:01:27 +0000974int sqliteKeywordCode(const char*, int);
drh80ff32f2001-11-04 18:32:46 +0000975int sqliteRunParser(Parse*, const char*, char **);
drh75897232000-05-29 14:26:00 +0000976void sqliteExec(Parse*);
977Expr *sqliteExpr(int, Expr*, Expr*, Token*);
drhe1b6a5b2000-07-29 13:06:59 +0000978void sqliteExprSpan(Expr*,Token*,Token*);
drh75897232000-05-29 14:26:00 +0000979Expr *sqliteExprFunction(ExprList*, Token*);
980void sqliteExprDelete(Expr*);
981ExprList *sqliteExprListAppend(ExprList*,Expr*,Token*);
982void sqliteExprListDelete(ExprList*);
drhe0bc4042002-06-25 01:09:11 +0000983int sqliteInit(sqlite*, char**);
drh1c2d8412003-03-31 00:30:47 +0000984void sqlitePragma(Parse*,Token*,Token*,int);
985void sqliteResetInternalSchema(sqlite*, int);
drhe0bc4042002-06-25 01:09:11 +0000986void sqliteBeginParse(Parse*,int);
drh5e00f6c2001-09-13 13:46:56 +0000987void sqliteRollbackInternalChanges(sqlite*);
drhe0bc4042002-06-25 01:09:11 +0000988void sqliteCommitInternalChanges(sqlite*);
drh969fa7c2002-02-18 18:30:32 +0000989Table *sqliteResultSetOfSelect(Parse*,char*,Select*);
drhe0bc4042002-06-25 01:09:11 +0000990void sqliteOpenMasterTable(Vdbe *v, int);
drhe5f9c642003-01-13 23:27:31 +0000991void sqliteStartTable(Parse*,Token*,Token*,int,int);
drh75897232000-05-29 14:26:00 +0000992void sqliteAddColumn(Parse*,Token*);
drh9cfcf5d2002-01-29 18:41:24 +0000993void sqliteAddNotNull(Parse*, int);
994void sqliteAddPrimaryKey(Parse*, IdList*, int);
drh382c0242001-10-06 16:33:02 +0000995void sqliteAddColumnType(Parse*,Token*,Token*);
drh7020f652000-06-03 18:06:52 +0000996void sqliteAddDefaultValue(Parse*,Token*,int);
drhfcb78a42003-01-18 20:11:05 +0000997int sqliteCollateType(const char*, int);
drh8e2ca022002-06-17 17:07:19 +0000998void sqliteAddCollateType(Parse*, int);
drh969fa7c2002-02-18 18:30:32 +0000999void sqliteEndTable(Parse*,Token*,Select*);
drh6276c1c2002-07-08 22:03:32 +00001000void sqliteCreateView(Parse*,Token*,Token*,Select*,int);
drh417be792002-03-03 18:59:40 +00001001int sqliteViewGetColumnNames(Parse*,Table*);
drh4ff6dfa2002-03-03 23:06:00 +00001002void sqliteDropTable(Parse*, Token*, int);
drh75897232000-05-29 14:26:00 +00001003void sqliteDeleteTable(sqlite*, Table*);
drh113088e2003-03-20 01:16:58 +00001004void sqliteInsert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
drh75897232000-05-29 14:26:00 +00001005IdList *sqliteIdListAppend(IdList*, Token*);
drhad2d8302002-05-24 20:31:36 +00001006int sqliteIdListIndex(IdList*,const char*);
drh113088e2003-03-20 01:16:58 +00001007SrcList *sqliteSrcListAppend(SrcList*, Token*, Token*);
drhad3cab52002-05-24 02:04:32 +00001008void sqliteSrcListAddAlias(SrcList*, Token*);
drh75897232000-05-29 14:26:00 +00001009void sqliteIdListDelete(IdList*);
drhad3cab52002-05-24 02:04:32 +00001010void sqliteSrcListDelete(SrcList*);
drhd24cc422003-03-27 12:51:24 +00001011void sqliteCreateIndex(Parse*,Token*,SrcList*,IdList*,int,int,Token*,Token*);
1012void sqliteDropIndex(Parse*, SrcList*);
drh38640e12002-07-05 21:42:36 +00001013void sqliteAddKeyType(Vdbe*, ExprList*);
1014void sqliteAddIdxKeyType(Vdbe*, Index*);
drh1b2e0322002-03-03 02:49:51 +00001015int sqliteSelect(Parse*, Select*, int, int, Select*, int, int*);
drhad3cab52002-05-24 02:04:32 +00001016Select *sqliteSelectNew(ExprList*,SrcList*,Expr*,ExprList*,Expr*,ExprList*,
drh9bbca4c2001-11-06 04:00:18 +00001017 int,int,int);
drh9bb61fe2000-06-05 16:01:39 +00001018void sqliteSelectDelete(Select*);
drhff78bd22002-02-27 01:47:11 +00001019void sqliteSelectUnbind(Select*);
drh812d7a22003-03-27 13:50:00 +00001020Table *sqliteSrcListLookup(Parse*, SrcList*);
1021int sqliteIsReadOnly(Parse*, Table*);
drh113088e2003-03-20 01:16:58 +00001022void sqliteDeleteFrom(Parse*, SrcList*, Expr*);
1023void sqliteUpdate(Parse*, SrcList*, ExprList*, Expr*, int);
drhe3184742002-06-19 14:27:05 +00001024WhereInfo *sqliteWhereBegin(Parse*, int, SrcList*, Expr*, int, ExprList**);
drh75897232000-05-29 14:26:00 +00001025void sqliteWhereEnd(WhereInfo*);
1026void sqliteExprCode(Parse*, Expr*);
drhf5905aa2002-05-26 20:54:33 +00001027void sqliteExprIfTrue(Parse*, Expr*, int, int);
1028void sqliteExprIfFalse(Parse*, Expr*, int, int);
drhd24cc422003-03-27 12:51:24 +00001029Table *sqliteFindTable(sqlite*,const char*, const char*);
1030Index *sqliteFindIndex(sqlite*,const char*, const char*);
drh6d4abfb2001-10-22 02:58:08 +00001031void sqliteUnlinkAndDeleteIndex(sqlite*,Index*);
drhd24cc422003-03-27 12:51:24 +00001032void sqliteCopy(Parse*, SrcList*, Token*, Token*, int);
drhdce2cbe2000-05-31 02:27:49 +00001033void sqliteVacuum(Parse*, Token*);
drhe17a7e32001-04-04 21:10:18 +00001034int sqliteGlobCompare(const unsigned char*,const unsigned char*);
drhdce2cbe2000-05-31 02:27:49 +00001035int sqliteLikeCompare(const unsigned char*,const unsigned char*);
drhcce7d172000-05-31 15:34:51 +00001036char *sqliteTableNameFromToken(Token*);
1037int sqliteExprCheck(Parse*, Expr*, int, int*);
drhc9b84a12002-06-20 11:36:48 +00001038int sqliteExprType(Expr*);
drhd8bc7082000-06-07 23:51:50 +00001039int sqliteExprCompare(Expr*, Expr*);
drhcce7d172000-05-31 15:34:51 +00001040int sqliteFuncId(Token*);
drhad3cab52002-05-24 02:04:32 +00001041int sqliteExprResolveIds(Parse*, int, SrcList*, ExprList*, Expr*);
drh22827922000-06-06 17:27:05 +00001042int sqliteExprAnalyzeAggregates(Parse*, Expr*);
drhd8bc7082000-06-07 23:51:50 +00001043Vdbe *sqliteGetVdbe(Parse*);
drhb8ca3072001-12-05 00:21:20 +00001044int sqliteRandomByte(void);
1045int sqliteRandomInteger(void);
drh001bbcb2003-03-19 03:14:00 +00001046void sqliteRollbackAll(sqlite*);
1047void sqliteCodeVerifySchema(Parse*);
drh1c928532002-01-31 15:54:21 +00001048void sqliteBeginTransaction(Parse*, int);
drhc4a3c772001-04-04 11:48:57 +00001049void sqliteCommitTransaction(Parse*);
1050void sqliteRollbackTransaction(Parse*);
drh92086432002-01-22 14:11:29 +00001051int sqliteExprIsConstant(Expr*);
drhe4de1fe2002-06-02 16:09:01 +00001052int sqliteExprIsInteger(Expr*, int*);
drha9f9d1c2002-06-29 02:20:08 +00001053int sqliteIsRowid(const char*);
drh38640e12002-07-05 21:42:36 +00001054void sqliteGenerateRowDelete(sqlite*, Vdbe*, Table*, int, int);
1055void sqliteGenerateRowIndexDelete(sqlite*, Vdbe*, Table*, int, char*);
drh0ca3e242002-01-29 23:07:02 +00001056void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
drhb419a922002-01-30 16:17:23 +00001057void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int);
drhcabb0812002-09-14 13:47:32 +00001058void sqliteBeginWriteOperation(Parse*, int, int);
drh1c928532002-01-31 15:54:21 +00001059void sqliteEndWriteOperation(Parse*);
drhff78bd22002-02-27 01:47:11 +00001060Expr *sqliteExprDup(Expr*);
drh4b59ab52002-08-24 18:24:51 +00001061void sqliteTokenCopy(Token*, Token*);
drhff78bd22002-02-27 01:47:11 +00001062ExprList *sqliteExprListDup(ExprList*);
drhad3cab52002-05-24 02:04:32 +00001063SrcList *sqliteSrcListDup(SrcList*);
drhff78bd22002-02-27 01:47:11 +00001064IdList *sqliteIdListDup(IdList*);
1065Select *sqliteSelectDup(Select*);
drh0bce8352002-02-28 00:41:10 +00001066FuncDef *sqliteFindFunction(sqlite*,const char*,int,int,int);
drh28f4b682002-06-09 10:14:18 +00001067void sqliteRegisterBuiltinFunctions(sqlite*);
drh247be432002-05-10 05:44:55 +00001068int sqliteSafetyOn(sqlite*);
1069int sqliteSafetyOff(sqlite*);
drhc22bd472002-05-10 13:14:07 +00001070int sqliteSafetyCheck(sqlite*);
drhe0bc4042002-06-25 01:09:11 +00001071void sqliteChangeCookie(sqlite*, Vdbe*);
drhd24cc422003-03-27 12:51:24 +00001072void sqliteCreateTrigger(Parse*, Token*, int, int, IdList*, SrcList*,
drh4b59ab52002-08-24 18:24:51 +00001073 int, Expr*, TriggerStep*, Token*);
drhd24cc422003-03-27 12:51:24 +00001074void sqliteDropTrigger(Parse*, SrcList*, int);
drhdc379452002-05-15 12:45:43 +00001075int sqliteTriggersExist(Parse* , Trigger* , int , int , int, ExprList*);
danielk19776f349032002-06-11 02:25:40 +00001076int sqliteCodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int,
1077 int, int);
drhdc379452002-05-15 12:45:43 +00001078void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
1079TriggerStep *sqliteTriggerSelectStep(Select*);
1080TriggerStep *sqliteTriggerInsertStep(Token*, IdList*, ExprList*, Select*, int);
1081TriggerStep *sqliteTriggerUpdateStep(Token*, ExprList*, Expr*, int);
1082TriggerStep *sqliteTriggerDeleteStep(Token*, Expr*);
drh1d1f3052002-05-21 13:18:25 +00001083void sqliteDeleteTrigger(Trigger*);
drh01f3f252002-05-24 16:14:15 +00001084int sqliteJoinType(Parse*, Token*, Token*, Token*);
drhc2eef3b2002-08-31 18:53:06 +00001085void sqliteCreateForeignKey(Parse*, IdList*, Token*, IdList*, int);
1086void sqliteDeferForeignKey(Parse*, int);
drhed6c8672003-01-12 18:02:16 +00001087#ifndef SQLITE_OMIT_AUTHORIZATION
1088 void sqliteAuthRead(Parse*,Expr*,SrcList*,int);
drhe5f9c642003-01-13 23:27:31 +00001089 int sqliteAuthCheck(Parse*,int, const char*, const char*);
drhed6c8672003-01-12 18:02:16 +00001090#else
1091# define sqliteAuthRead(a,b,c,d)
drhe5f9c642003-01-13 23:27:31 +00001092# define sqliteAuthCheck(a,b,c,d) SQLITE_OK
drhed6c8672003-01-12 18:02:16 +00001093#endif
drh1c2d8412003-03-31 00:30:47 +00001094void sqliteAttach(Parse*, Token*, Token*);
1095void sqliteDetach(Parse*, Token*);