Start of experimental implementation of SQL window functions. Does not yet
work.
FossilOrigin-Name: 3781e520854808fe02ad3fe77dd11fc917448c58ff1fd79123289dd91937decd
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 7b19e0a..8a1376f 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1107,6 +1107,7 @@
typedef struct VtabCtx VtabCtx;
typedef struct Walker Walker;
typedef struct WhereInfo WhereInfo;
+typedef struct Window Window;
typedef struct With With;
/* A VList object records a mapping between parameters/variables/wildcards
@@ -1588,6 +1589,8 @@
FuncDef *pNext; /* Next function with same name */
void (*xSFunc)(sqlite3_context*,int,sqlite3_value**); /* func or agg-step */
void (*xFinalize)(sqlite3_context*); /* Agg finalizer */
+ void (*xValue)(sqlite3_context*); /* Current agg value */
+ void (*xInverse)(sqlite3_context*,int,sqlite3_value**); /* inverse agg-step */
const char *zName; /* SQL name of the function. */
union {
FuncDef *pHash; /* Next with a different name but the same hash */
@@ -1678,6 +1681,12 @@
** are interpreted in the same way as the first 4 parameters to
** FUNCTION().
**
+** WFUNCTION(zName, nArg, iArg, xStep, xFinal, xValue, xInverse)
+** Used to create an aggregate function definition implemented by
+** the C functions xStep and xFinal. The first four parameters
+** are interpreted in the same way as the first 4 parameters to
+** FUNCTION().
+**
** LIKEFUNC(zName, nArg, pArg, flags)
** Used to create a scalar function definition of a function zName
** that accepts nArg arguments and is implemented by a call to C
@@ -1688,31 +1697,35 @@
*/
#define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
{nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
- SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+ SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }
#define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
{nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
- SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+ SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }
#define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
{nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8, \
- 0, 0, xFunc, 0, #zName, {0} }
+ 0, 0, xFunc, 0, 0, 0, #zName, {0} }
#define PURE_DATE(zName, nArg, iArg, bNC, xFunc) \
{nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|SQLITE_FUNC_CONSTANT, \
- (void*)&sqlite3Config, 0, xFunc, 0, #zName, {0} }
+ (void*)&sqlite3Config, 0, xFunc, 0, 0, 0, #zName, {0} }
#define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
{nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
- SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+ SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }
#define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
{nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
- pArg, 0, xFunc, 0, #zName, }
+ pArg, 0, xFunc, 0, 0, 0, #zName, }
#define LIKEFUNC(zName, nArg, arg, flags) \
{nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
- (void *)arg, 0, likeFunc, 0, #zName, {0} }
+ (void *)arg, 0, likeFunc, 0, 0, 0, #zName, {0} }
#define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
{nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
- SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName, {0}}
+ SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,0,0,#zName, {0}}
#define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
{nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
- SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName, {0}}
+ SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,0,0,#zName, {0}}
+
+#define WFUNCTION(zName, nArg, arg, xStep, xFinal, xValue, xInverse) \
+ {nArg, SQLITE_UTF8, \
+ SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,xValue,xInverse,#zName, {0}}
/*
** All current savepoints are stored in a linked list starting at
@@ -2413,6 +2426,7 @@
AggInfo *pAggInfo; /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
Table *pTab; /* Table for TK_COLUMN expressions. Can be NULL
** for a column of an index on an expression */
+ Window *pWin; /* Window definition for window functions */
};
/*
@@ -2699,6 +2713,7 @@
int nRef; /* Number of names resolved by this context */
int nErr; /* Number of errors encountered while resolving names */
u16 ncFlags; /* Zero or more NC_* flags defined below */
+ Window *pWin; /* List of window functions in this context */
};
/*
@@ -2721,6 +2736,7 @@
#define NC_UUpsert 0x0200 /* True if uNC.pUpsert is used */
#define NC_MinMaxAgg 0x1000 /* min/max aggregates seen. See note above */
#define NC_Complex 0x2000 /* True if a function or subquery seen */
+#define NC_AllowWin 0x4000 /* Window functions are allowed here */
/*
** An instance of the following object describes a single ON CONFLICT
@@ -2788,6 +2804,7 @@
Select *pNext; /* Next select to the left in a compound */
Expr *pLimit; /* LIMIT expression. NULL means not used. */
With *pWith; /* WITH clause attached to this select. Or NULL. */
+ Window *pWin; /* List of window functions */
};
/*
@@ -3401,6 +3418,7 @@
struct IdxExprTrans *pIdxTrans; /* Convert idxed expr to column */
ExprList *pGroupBy; /* GROUP BY clause */
Select *pSelect; /* HAVING to WHERE clause ctx */
+ struct WindowRewrite *pRewrite; /* Window rewrite context */
} u;
};
@@ -3451,6 +3469,31 @@
};
#endif /* SQLITE_DEBUG */
+struct Window {
+ Expr *pFilter;
+ ExprList *pPartition;
+ ExprList *pOrderBy;
+ u8 eType; /* TK_RANGE or TK_ROWS */
+ u8 eStart; /* UNBOUNDED, CURRENT, PRECEDING or FOLLOWING */
+ u8 eEnd; /* UNBOUNDED, CURRENT, PRECEDING or FOLLOWING */
+ Expr *pStart; /* Expression for "<expr> PRECEDING" */
+ Expr *pEnd; /* Expression for "<expr> FOLLOWING" */
+ Window *pNextWin; /* Next window function belonging to this SELECT */
+ int iEphCsr; /* Temp table used by this window */
+ int regAccum;
+ int regResult;
+ FuncDef *pFunc;
+ int nArg;
+
+ Expr *pOwner; /* Expression object this window is attached to */
+ int nBufferCol; /* Number of columns in buffer table */
+ int iArgCol; /* Offset of first argument for this function */
+};
+
+void sqlite3WindowDelete(sqlite3*, Window*);
+Window *sqlite3WindowAlloc(Parse*, int, int, Expr*, int , Expr*);
+void sqlite3WindowAttach(Parse*, Expr*, Window*);
+
/*
** Assuming zIn points to the first byte of a UTF-8 character,
** advance zIn to point to the first byte of the next UTF-8 character.