src/parse.y

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
*/

// All token codes are small integers with #defines that begin with "TK_"
%token_prefix TK_

// The type of the data attached to each token is Token.  This is also the
// default type for non-terminals.
//
%token_type {Token}
%default_type {Token}

// The generated parser function takes a 4th argument as follows:
%extra_argument {Parse *pParse}

// This code runs whenever there is a syntax error
//
%syntax_error {
  UNUSED_PARAMETER(yymajor);  /* Silence some compiler warnings */
  if( TOKEN.z[0] ){
    sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
  }else{
    sqlite3ErrorMsg(pParse, "incomplete input");
  }
}
%stack_overflow {
  sqlite3ErrorMsg(pParse, "parser stack overflow");
}

// The name of the generated procedure that implements the parser
// is as follows:
%name sqlite3Parser

// The following text is included near the beginning of the C source
// code file that implements the parser.
//
%include {
#include "sqliteInt.h"

/*
** Disable all error recovery processing in the parser push-down
** automaton.
*/
#define YYNOERRORRECOVERY 1

/*
** Make yytestcase() the same as testcase()
*/
#define yytestcase(X) testcase(X)

/*
** Indicate that sqlite3ParserFree() will never be called with a null
** pointer.
*/
#define YYPARSEFREENEVERNULL 1

/*
** In the amalgamation, the parse.c file generated by lemon and the
** tokenize.c file are concatenated.  In that case, sqlite3RunParser()
** has access to the the size of the yyParser object and so the parser
** engine can be allocated from stack.  In that case, only the
** sqlite3ParserInit() and sqlite3ParserFinalize() routines are invoked
** and the sqlite3ParserAlloc() and sqlite3ParserFree() routines can be
** omitted.
*/
#ifdef SQLITE_AMALGAMATION
# define sqlite3Parser_ENGINEALWAYSONSTACK 1
#endif

/*
** Alternative datatype for the argument to the malloc() routine passed
** into sqlite3ParserAlloc().  The default is size_t.
*/
#define YYMALLOCARGTYPE  u64

/*
** An instance of the following structure describes the event of a
** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
** TK_DELETE, or TK_INSTEAD.  If the event is of the form
**
**      UPDATE ON (a,b,c)
**
** Then the "b" IdList records the list "a,b,c".
*/
struct TrigEvent { int a; IdList * b; };

/*
** Disable lookaside memory allocation for objects that might be
** shared across database connections.
*/
static void disableLookaside(Parse *pParse){
  pParse->disableLookaside++;
  pParse->db->lookaside.bDisable++;
}

} // end %include

// Input is a single SQL command
input ::= cmdlist.
cmdlist ::= cmdlist ecmd.
cmdlist ::= ecmd.
ecmd ::= SEMI.
ecmd ::= explain cmdx SEMI.
explain ::= .
%ifndef SQLITE_OMIT_EXPLAIN
explain ::= EXPLAIN.              { pParse->explain = 1; }
explain ::= EXPLAIN QUERY PLAN.   { pParse->explain = 2; }
%endif  SQLITE_OMIT_EXPLAIN
cmdx ::= cmd.           { sqlite3FinishCoding(pParse); }

///////////////////// Begin and end transactions. ////////////////////////////
//

cmd ::= BEGIN transtype(Y) trans_opt.  {sqlite3BeginTransaction(pParse, Y);}
trans_opt ::= .
trans_opt ::= TRANSACTION.
trans_opt ::= TRANSACTION nm.
%type transtype {int}
transtype(A) ::= .             {A = TK_DEFERRED;}
transtype(A) ::= DEFERRED(X).  {A = @X; /*A-overwrites-X*/}
transtype(A) ::= IMMEDIATE(X). {A = @X; /*A-overwrites-X*/}
transtype(A) ::= EXCLUSIVE(X). {A = @X; /*A-overwrites-X*/}
cmd ::= COMMIT|END(X) trans_opt.   {sqlite3EndTransaction(pParse,@X);}
cmd ::= ROLLBACK(X) trans_opt.     {sqlite3EndTransaction(pParse,@X);}

savepoint_opt ::= SAVEPOINT.
savepoint_opt ::= .
cmd ::= SAVEPOINT nm(X). {
  sqlite3Savepoint(pParse, SAVEPOINT_BEGIN, &X);
}
cmd ::= RELEASE savepoint_opt nm(X). {
  sqlite3Savepoint(pParse, SAVEPOINT_RELEASE, &X);
}
cmd ::= ROLLBACK trans_opt TO savepoint_opt nm(X). {
  sqlite3Savepoint(pParse, SAVEPOINT_ROLLBACK, &X);
}

///////////////////// The CREATE TABLE statement ////////////////////////////
//
cmd ::= create_table create_table_args.
create_table ::= createkw temp(T) TABLE ifnotexists(E) nm(Y) dbnm(Z). {
   sqlite3StartTable(pParse,&Y,&Z,T,0,0,E);
}
createkw(A) ::= CREATE(A).  {disableLookaside(pParse);}

%type ifnotexists {int}
ifnotexists(A) ::= .              {A = 0;}
ifnotexists(A) ::= IF NOT EXISTS. {A = 1;}
%type temp {int}
%ifndef SQLITE_OMIT_TEMPDB
temp(A) ::= TEMP.  {A = 1;}
%endif  SQLITE_OMIT_TEMPDB
temp(A) ::= .      {A = 0;}
create_table_args ::= LP columnlist conslist_opt(X) RP(E) table_options(F). {
  sqlite3EndTable(pParse,&X,&E,F,0);
}
create_table_args ::= AS select(S). {
  sqlite3EndTable(pParse,0,0,0,S);
  sqlite3SelectDelete(pParse->db, S);
}
%type table_options {int}
table_options(A) ::= .    {A = 0;}
table_options(A) ::= WITHOUT nm(X). {
  if( X.n==5 && sqlite3_strnicmp(X.z,"rowid",5)==0 ){
    A = TF_WithoutRowid | TF_NoVisibleRowid;
  }else{
    A = 0;
    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", X.n, X.z);
  }
}
columnlist ::= columnlist COMMA columnname carglist.
columnlist ::= columnname carglist.
columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}

// Declare some tokens early in order to influence their values, to 
// improve performance and reduce the executable size.  The goal here is
// to get the "jump" operations in ISNULL through ESCAPE to have numeric
// values that are early enough so that all jump operations are clustered
// at the beginning, but also so that the comparison tokens NE through GE
// are as large as possible so that they are near to FUNCTION, which is a
// token synthesized by addopcodes.tcl.
//
%token ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST.
%token CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL.
%token OR AND NOT IS MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
%token GT LE LT GE ESCAPE.

// The following directive causes tokens ABORT, AFTER, ASC, etc. to
// fallback to ID if they will not parse as their original value.
// This obviates the need for the "id" nonterminal.
//
%fallback ID
  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
  CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
  QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
  ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.

// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer.  Keeping the operators together
// causes them to be assigned integer values that are close together,
// which keeps parser tables smaller.
//
// The token values assigned to these symbols is determined by the order
// in which lemon first sees them.  It must be the case that ISNULL/NOTNULL,
// NE/EQ, GT/LE, and GE/LT are separated by only a single value.  See
// the sqlite3ExprIfFalse() routine for additional information on this
// constraint.
//
%left OR.
%left AND.
%right NOT.
%left IS MATCH LIKE_KW BETWEEN IN ISNULL NOTNULL NE EQ.
%left GT LE LT GE.
%right ESCAPE.
%left BITAND BITOR LSHIFT RSHIFT.
%left PLUS MINUS.
%left STAR SLASH REM.
%left CONCAT.
%left COLLATE.
%right BITNOT.

// An IDENTIFIER can be a generic identifier, or one of several
// keywords.  Any non-standard keyword can also be an identifier.
//
%token_class id  ID|INDEXED.


// And "ids" is an identifer-or-string.
//
%token_class ids  ID|STRING.

// The name of a column or table can be any of the following:
//
%type nm {Token}
nm(A) ::= id(A).
nm(A) ::= STRING(A).
nm(A) ::= JOIN_KW(A).

// A typetoken is really zero or more tokens that form a type name such
// as can be found after the column name in a CREATE TABLE statement.
// Multiple tokens are concatenated to form the value of the typetoken.
//
%type typetoken {Token}
typetoken(A) ::= .   {A.n = 0; A.z = 0;}
typetoken(A) ::= typename(A).
typetoken(A) ::= typename(A) LP signed RP(Y). {
  A.n = (int)(&Y.z[Y.n] - A.z);
}
typetoken(A) ::= typename(A) LP signed COMMA signed RP(Y). {
  A.n = (int)(&Y.z[Y.n] - A.z);
}
%type typename {Token}
typename(A) ::= ids(A).
typename(A) ::= typename(A) ids(Y). {A.n=Y.n+(int)(Y.z-A.z);}
signed ::= plus_num.
signed ::= minus_num.

// The scanpt non-terminal takes a value which is a pointer to the
// input text just past the last token that has been shifted into
// the parser.  By surrounding some phrase in the grammar with two
// scanpt non-terminals, we can capture the input text for that phrase.
// For example:
//
//      something ::= .... scanpt(A) phrase scanpt(Z).
//
// The text that is parsed as "phrase" is a string starting at A
// and containing (int)(Z-A) characters.  There might be some extra
// whitespace on either end of the text, but that can be removed in
// post-processing, if needed.
//
%type scanpt {const char*}
scanpt(A) ::= . {
  assert( yyLookahead!=YYNOCODE );
  A = yyLookaheadToken.z;
}

// "carglist" is a list of additional constraints that come after the
// column name and column type in a CREATE TABLE statement.
//
carglist ::= carglist ccons.
carglist ::= .
ccons ::= CONSTRAINT nm(X).           {pParse->constraintName = X;}
ccons ::= DEFAULT scanpt(A) term(X) scanpt(Z).
                            {sqlite3AddDefaultValue(pParse,X,A,Z);}
ccons ::= DEFAULT LP(A) expr(X) RP(Z).
                            {sqlite3AddDefaultValue(pParse,X,A.z+1,Z.z);}
ccons ::= DEFAULT PLUS(A) term(X) scanpt(Z).
                            {sqlite3AddDefaultValue(pParse,X,A.z,Z);}
ccons ::= DEFAULT MINUS(A) term(X) scanpt(Z).      {
  Expr *p = sqlite3PExpr(pParse, TK_UMINUS, X, 0);
  sqlite3AddDefaultValue(pParse,p,A.z,Z);
}
ccons ::= DEFAULT scanpt id(X).       {
  Expr *p = tokenExpr(pParse, TK_STRING, X);
  sqlite3AddDefaultValue(pParse,p,X.z,X.z+X.n);
}

// In addition to the type name, we also care about the primary key and
// UNIQUE constraints.
//
ccons ::= NULL onconf.
ccons ::= NOT NULL onconf(R).    {sqlite3AddNotNull(pParse, R);}
ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
                                 {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
ccons ::= UNIQUE onconf(R).      {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0,0,
                                   SQLITE_IDXTYPE_UNIQUE);}
ccons ::= CHECK LP expr(X) RP.   {sqlite3AddCheckConstraint(pParse,X);}
ccons ::= REFERENCES nm(T) eidlist_opt(TA) refargs(R).
                                 {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
ccons ::= defer_subclause(D).    {sqlite3DeferForeignKey(pParse,D);}
ccons ::= COLLATE ids(C).        {sqlite3AddCollateType(pParse, &C);}

// The optional AUTOINCREMENT keyword
%type autoinc {int}
autoinc(X) ::= .          {X = 0;}
autoinc(X) ::= AUTOINCR.  {X = 1;}

// The next group of rules parses the arguments to a REFERENCES clause
// that determine if the referential integrity checking is deferred or
// or immediate and which determine what action to take if a ref-integ
// check fails.
//
%type refargs {int}
refargs(A) ::= .                  { A = OE_None*0x0101; /* EV: R-19803-45884 */}
refargs(A) ::= refargs(A) refarg(Y). { A = (A & ~Y.mask) | Y.value; }
%type refarg {struct {int value; int mask;}}
refarg(A) ::= MATCH nm.              { A.value = 0;     A.mask = 0x000000; }
refarg(A) ::= ON INSERT refact.      { A.value = 0;     A.mask = 0x000000; }
refarg(A) ::= ON DELETE refact(X).   { A.value = X;     A.mask = 0x0000ff; }
refarg(A) ::= ON UPDATE refact(X).   { A.value = X<<8;  A.mask = 0x00ff00; }
%type refact {int}
refact(A) ::= SET NULL.              { A = OE_SetNull;  /* EV: R-33326-45252 */}
refact(A) ::= SET DEFAULT.           { A = OE_SetDflt;  /* EV: R-33326-45252 */}
refact(A) ::= CASCADE.               { A = OE_Cascade;  /* EV: R-33326-45252 */}
refact(A) ::= RESTRICT.              { A = OE_Restrict; /* EV: R-33326-45252 */}
refact(A) ::= NO ACTION.             { A = OE_None;     /* EV: R-33326-45252 */}
%type defer_subclause {int}
defer_subclause(A) ::= NOT DEFERRABLE init_deferred_pred_opt.     {A = 0;}
defer_subclause(A) ::= DEFERRABLE init_deferred_pred_opt(X).      {A = X;}
%type init_deferred_pred_opt {int}
init_deferred_pred_opt(A) ::= .                       {A = 0;}
init_deferred_pred_opt(A) ::= INITIALLY DEFERRED.     {A = 1;}
init_deferred_pred_opt(A) ::= INITIALLY IMMEDIATE.    {A = 0;}

conslist_opt(A) ::= .                         {A.n = 0; A.z = 0;}
conslist_opt(A) ::= COMMA(A) conslist.
conslist ::= conslist tconscomma tcons.
conslist ::= tcons.
tconscomma ::= COMMA.            {pParse->constraintName.n = 0;}
tconscomma ::= .
tcons ::= CONSTRAINT nm(X).      {pParse->constraintName = X;}
tcons ::= PRIMARY KEY LP sortlist(X) autoinc(I) RP onconf(R).
                                 {sqlite3AddPrimaryKey(pParse,X,R,I,0);}
tcons ::= UNIQUE LP sortlist(X) RP onconf(R).
                                 {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0,0,0,
                                       SQLITE_IDXTYPE_UNIQUE);}
tcons ::= CHECK LP expr(E) RP onconf.
                                 {sqlite3AddCheckConstraint(pParse,E);}
tcons ::= FOREIGN KEY LP eidlist(FA) RP
          REFERENCES nm(T) eidlist_opt(TA) refargs(R) defer_subclause_opt(D). {
    sqlite3CreateForeignKey(pParse, FA, &T, TA, R);
    sqlite3DeferForeignKey(pParse, D);
}
%type defer_subclause_opt {int}
defer_subclause_opt(A) ::= .                    {A = 0;}
defer_subclause_opt(A) ::= defer_subclause(A).

// The following is a non-standard extension that allows us to declare the
// default behavior when there is a constraint conflict.
//
%type onconf {int}
%type orconf {int}
%type resolvetype {int}
onconf(A) ::= .                              {A = OE_Default;}
onconf(A) ::= ON CONFLICT resolvetype(X).    {A = X;}
orconf(A) ::= .                              {A = OE_Default;}
orconf(A) ::= OR resolvetype(X).             {A = X;}
resolvetype(A) ::= raisetype(A).
resolvetype(A) ::= IGNORE.                   {A = OE_Ignore;}
resolvetype(A) ::= REPLACE.                  {A = OE_Replace;}

////////////////////////// The DROP TABLE /////////////////////////////////////
//
cmd ::= DROP TABLE ifexists(E) fullname(X). {
  sqlite3DropTable(pParse, X, 0, E);
}
%type ifexists {int}
ifexists(A) ::= IF EXISTS.   {A = 1;}
ifexists(A) ::= .            {A = 0;}

///////////////////// The CREATE VIEW statement /////////////////////////////
//
%ifndef SQLITE_OMIT_VIEW
cmd ::= createkw(X) temp(T) VIEW ifnotexists(E) nm(Y) dbnm(Z) eidlist_opt(C)
          AS select(S). {
  sqlite3CreateView(pParse, &X, &Y, &Z, C, S, T, E);
}
cmd ::= DROP VIEW ifexists(E) fullname(X). {
  sqlite3DropTable(pParse, X, 1, E);
}
%endif  SQLITE_OMIT_VIEW

//////////////////////// The SELECT statement /////////////////////////////////
//
cmd ::= select(X).  {
  SelectDest dest = {SRT_Output, 0, 0, 0, 0, 0};
  sqlite3Select(pParse, X, &dest);
  sqlite3SelectDelete(pParse->db, X);
}

%type select {Select*}
%destructor select {sqlite3SelectDelete(pParse->db, $$);}
%type selectnowith {Select*}
%destructor selectnowith {sqlite3SelectDelete(pParse->db, $$);}
%type oneselect {Select*}
%destructor oneselect {sqlite3SelectDelete(pParse->db, $$);}

%include {
  /*
  ** For a compound SELECT statement, make sure p->pPrior->pNext==p for
  ** all elements in the list.  And make sure list length does not exceed
  ** SQLITE_LIMIT_COMPOUND_SELECT.
  */
  static void parserDoubleLinkSelect(Parse *pParse, Select *p){
    if( p->pPrior ){
      Select *pNext = 0, *pLoop;
      int mxSelect, cnt = 0;
      for(pLoop=p; pLoop; pNext=pLoop, pLoop=pLoop->pPrior, cnt++){
        pLoop->pNext = pNext;
        pLoop->selFlags |= SF_Compound;
      }
      if( (p->selFlags & SF_MultiValue)==0 && 
        (mxSelect = pParse->db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT])>0 &&
        cnt>mxSelect
      ){
        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
      }
    }
  }
}

select(A) ::= with(W) selectnowith(X). {
  Select *p = X;
  if( p ){
    p->pWith = W;
    parserDoubleLinkSelect(pParse, p);
  }else{
    sqlite3WithDelete(pParse->db, W);
  }
  A = p; /*A-overwrites-W*/
}

selectnowith(A) ::= oneselect(A).
%ifndef SQLITE_OMIT_COMPOUND_SELECT
selectnowith(A) ::= selectnowith(A) multiselect_op(Y) oneselect(Z).  {
  Select *pRhs = Z;
  Select *pLhs = A;
  if( pRhs && pRhs->pPrior ){
    SrcList *pFrom;
    Token x;
    x.n = 0;
    parserDoubleLinkSelect(pParse, pRhs);
    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0);
  }
  if( pRhs ){
    pRhs->op = (u8)Y;
    pRhs->pPrior = pLhs;
    if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;
    pRhs->selFlags &= ~SF_MultiValue;
    if( Y!=TK_ALL ) pParse->hasCompound = 1;
  }else{
    sqlite3SelectDelete(pParse->db, pLhs);
  }
  A = pRhs;
}
%type multiselect_op {int}
multiselect_op(A) ::= UNION(OP).             {A = @OP; /*A-overwrites-OP*/}
multiselect_op(A) ::= UNION ALL.             {A = TK_ALL;}
multiselect_op(A) ::= EXCEPT|INTERSECT(OP).  {A = @OP; /*A-overwrites-OP*/}
%endif SQLITE_OMIT_COMPOUND_SELECT
oneselect(A) ::= SELECT(S) distinct(D) selcollist(W) from(X) where_opt(Y)
                 groupby_opt(P) having_opt(Q) orderby_opt(Z) limit_opt(L). {
#if SELECTTRACE_ENABLED
  Token s = S; /*A-overwrites-S*/
#endif
  A = sqlite3SelectNew(pParse,W,X,Y,P,Q,Z,D,L);
#if SELECTTRACE_ENABLED
  /* Populate the Select.zSelName[] string that is used to help with
  ** query planner debugging, to differentiate between multiple Select
  ** objects in a complex query.
  **
  ** If the SELECT keyword is immediately followed by a C-style comment
  ** then extract the first few alphanumeric characters from within that
  ** comment to be the zSelName value.  Otherwise, the label is #N where
  ** is an integer that is incremented with each SELECT statement seen.
  */
  if( A!=0 ){
    const char *z = s.z+6;
    int i;
    sqlite3_snprintf(sizeof(A->zSelName), A->zSelName, "#%d",
                     ++pParse->nSelect);
    while( z[0]==' ' ) z++;
    if( z[0]=='/' && z[1]=='*' ){
      z += 2;
      while( z[0]==' ' ) z++;
      for(i=0; sqlite3Isalnum(z[i]); i++){}
      sqlite3_snprintf(sizeof(A->zSelName), A->zSelName, "%.*s", i, z);
    }
  }
#endif /* SELECTRACE_ENABLED */
}
oneselect(A) ::= values(A).

%type values {Select*}
%destructor values {sqlite3SelectDelete(pParse->db, $$);}
values(A) ::= VALUES LP nexprlist(X) RP. {
  A = sqlite3SelectNew(pParse,X,0,0,0,0,0,SF_Values,0);
}
values(A) ::= values(A) COMMA LP exprlist(Y) RP. {
  Select *pRight, *pLeft = A;
  pRight = sqlite3SelectNew(pParse,Y,0,0,0,0,0,SF_Values|SF_MultiValue,0);
  if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;
  if( pRight ){
    pRight->op = TK_ALL;
    pRight->pPrior = pLeft;
    A = pRight;
  }else{
    A = pLeft;
  }
}

// The "distinct" nonterminal is true (1) if the DISTINCT keyword is
// present and false (0) if it is not.
//
%type distinct {int}
distinct(A) ::= DISTINCT.   {A = SF_Distinct;}
distinct(A) ::= ALL.        {A = SF_All;}
distinct(A) ::= .           {A = 0;}

// selcollist is a list of expressions that are to become the return
// values of the SELECT statement.  The "*" in statements like
// "SELECT * FROM ..." is encoded as a special expression with an
// opcode of TK_ASTERISK.
//
%type selcollist {ExprList*}
%destructor selcollist {sqlite3ExprListDelete(pParse->db, $$);}
%type sclp {ExprList*}
%destructor sclp {sqlite3ExprListDelete(pParse->db, $$);}
sclp(A) ::= selcollist(A) COMMA.
sclp(A) ::= .                                {A = 0;}
selcollist(A) ::= sclp(A) scanpt(B) expr(X) scanpt(Z) as(Y).     {
   A = sqlite3ExprListAppend(pParse, A, X);
   if( Y.n>0 ) sqlite3ExprListSetName(pParse, A, &Y, 1);
   sqlite3ExprListSetSpan(pParse,A,B,Z);
}
selcollist(A) ::= sclp(A) scanpt STAR. {
  Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);
  A = sqlite3ExprListAppend(pParse, A, p);
}
selcollist(A) ::= sclp(A) scanpt nm(X) DOT STAR. {
  Expr *pRight = sqlite3PExpr(pParse, TK_ASTERISK, 0, 0);
  Expr *pLeft = sqlite3ExprAlloc(pParse->db, TK_ID, &X, 1);
  Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);
  A = sqlite3ExprListAppend(pParse,A, pDot);
}

// An option "AS <id>" phrase that can follow one of the expressions that
// define the result set, or one of the tables in the FROM clause.
//
%type as {Token}
as(X) ::= AS nm(Y).    {X = Y;}
as(X) ::= ids(X).
as(X) ::= .            {X.n = 0; X.z = 0;}


%type seltablist {SrcList*}
%destructor seltablist {sqlite3SrcListDelete(pParse->db, $$);}
%type stl_prefix {SrcList*}
%destructor stl_prefix {sqlite3SrcListDelete(pParse->db, $$);}
%type from {SrcList*}
%destructor from {sqlite3SrcListDelete(pParse->db, $$);}

// A complete FROM clause.
//
from(A) ::= .                {A = sqlite3DbMallocZero(pParse->db, sizeof(*A));}
from(A) ::= FROM seltablist(X). {
  A = X;
  sqlite3SrcListShiftJoinType(A);
}

// "seltablist" is a "Select Table List" - the content of the FROM clause
// in a SELECT statement.  "stl_prefix" is a prefix of this list.
//
stl_prefix(A) ::= seltablist(A) joinop(Y).    {
   if( ALWAYS(A && A->nSrc>0) ) A->a[A->nSrc-1].fg.jointype = (u8)Y;
}
stl_prefix(A) ::= .                           {A = 0;}
seltablist(A) ::= stl_prefix(A) nm(Y) dbnm(D) as(Z) indexed_opt(I)
                  on_opt(N) using_opt(U). {
  A = sqlite3SrcListAppendFromTerm(pParse,A,&Y,&D,&Z,0,N,U);
  sqlite3SrcListIndexedBy(pParse, A, &I);
}
seltablist(A) ::= stl_prefix(A) nm(Y) dbnm(D) LP exprlist(E) RP as(Z)
                  on_opt(N) using_opt(U). {
  A = sqlite3SrcListAppendFromTerm(pParse,A,&Y,&D,&Z,0,N,U);
  sqlite3SrcListFuncArgs(pParse, A, E);
}
%ifndef SQLITE_OMIT_SUBQUERY
  seltablist(A) ::= stl_prefix(A) LP select(S) RP
                    as(Z) on_opt(N) using_opt(U). {
    A = sqlite3SrcListAppendFromTerm(pParse,A,0,0,&Z,S,N,U);
  }
  seltablist(A) ::= stl_prefix(A) LP seltablist(F) RP
                    as(Z) on_opt(N) using_opt(U). {
    if( A==0 && Z.n==0 && N==0 && U==0 ){
      A = F;
    }else if( F->nSrc==1 ){
      A = sqlite3SrcListAppendFromTerm(pParse,A,0,0,&Z,0,N,U);
      if( A ){
        struct SrcList_item *pNew = &A->a[A->nSrc-1];
        struct SrcList_item *pOld = F->a;
        pNew->zName = pOld->zName;
        pNew->zDatabase = pOld->zDatabase;
        pNew->pSelect = pOld->pSelect;
        pOld->zName = pOld->zDatabase = 0;
        pOld->pSelect = 0;
      }
      sqlite3SrcListDelete(pParse->db, F);
    }else{
      Select *pSubquery;
      sqlite3SrcListShiftJoinType(F);
      pSubquery = sqlite3SelectNew(pParse,0,F,0,0,0,0,SF_NestedFrom,0);
      A = sqlite3SrcListAppendFromTerm(pParse,A,0,0,&Z,pSubquery,N,U);
    }
  }
%endif  SQLITE_OMIT_SUBQUERY

%type dbnm {Token}
dbnm(A) ::= .          {A.z=0; A.n=0;}
dbnm(A) ::= DOT nm(X). {A = X;}

%type fullname {SrcList*}
%destructor fullname {sqlite3SrcListDelete(pParse->db, $$);}
fullname(A) ::= nm(X) dbnm(Y).  
   {A = sqlite3SrcListAppend(pParse->db,0,&X,&Y); /*A-overwrites-X*/}

%type joinop {int}
joinop(X) ::= COMMA|JOIN.              { X = JT_INNER; }
joinop(X) ::= JOIN_KW(A) JOIN.
                  {X = sqlite3JoinType(pParse,&A,0,0);  /*X-overwrites-A*/}
joinop(X) ::= JOIN_KW(A) nm(B) JOIN.
                  {X = sqlite3JoinType(pParse,&A,&B,0); /*X-overwrites-A*/}
joinop(X) ::= JOIN_KW(A) nm(B) nm(C) JOIN.
                  {X = sqlite3JoinType(pParse,&A,&B,&C);/*X-overwrites-A*/}

%type on_opt {Expr*}
%destructor on_opt {sqlite3ExprDelete(pParse->db, $$);}
on_opt(N) ::= ON expr(E).   {N = E;}
on_opt(N) ::= .             {N = 0;}

// Note that this block abuses the Token type just a little. If there is
// no "INDEXED BY" clause, the returned token is empty (z==0 && n==0). If
// there is an INDEXED BY clause, then the token is populated as per normal,
// with z pointing to the token data and n containing the number of bytes
// in the token.
//
// If there is a "NOT INDEXED" clause, then (z==0 && n==1), which is 
// normally illegal. The sqlite3SrcListIndexedBy() function 
// recognizes and interprets this as a special case.
//
%type indexed_opt {Token}
indexed_opt(A) ::= .                 {A.z=0; A.n=0;}
indexed_opt(A) ::= INDEXED BY nm(X). {A = X;}
indexed_opt(A) ::= NOT INDEXED.      {A.z=0; A.n=1;}

%type using_opt {IdList*}
%destructor using_opt {sqlite3IdListDelete(pParse->db, $$);}
using_opt(U) ::= USING LP idlist(L) RP.  {U = L;}
using_opt(U) ::= .                        {U = 0;}


%type orderby_opt {ExprList*}
%destructor orderby_opt {sqlite3ExprListDelete(pParse->db, $$);}

// the sortlist non-terminal stores a list of expression where each
// expression is optionally followed by ASC or DESC to indicate the
// sort order.
//
%type sortlist {ExprList*}
%destructor sortlist {sqlite3ExprListDelete(pParse->db, $$);}

orderby_opt(A) ::= .                          {A = 0;}
orderby_opt(A) ::= ORDER BY sortlist(X).      {A = X;}
sortlist(A) ::= sortlist(A) COMMA expr(Y) sortorder(Z). {
  A = sqlite3ExprListAppend(pParse,A,Y);
  sqlite3ExprListSetSortOrder(A,Z);
}
sortlist(A) ::= expr(Y) sortorder(Z). {
  A = sqlite3ExprListAppend(pParse,0,Y); /*A-overwrites-Y*/
  sqlite3ExprListSetSortOrder(A,Z);
}

%type sortorder {int}

sortorder(A) ::= ASC.           {A = SQLITE_SO_ASC;}
sortorder(A) ::= DESC.          {A = SQLITE_SO_DESC;}
sortorder(A) ::= .              {A = SQLITE_SO_UNDEFINED;}

%type groupby_opt {ExprList*}
%destructor groupby_opt {sqlite3ExprListDelete(pParse->db, $$);}
groupby_opt(A) ::= .                      {A = 0;}
groupby_opt(A) ::= GROUP BY nexprlist(X). {A = X;}

%type having_opt {Expr*}
%destructor having_opt {sqlite3ExprDelete(pParse->db, $$);}
having_opt(A) ::= .                {A = 0;}
having_opt(A) ::= HAVING expr(X).  {A = X;}

%type limit_opt {Expr*}

// The destructor for limit_opt will never fire in the current grammar.
// The limit_opt non-terminal only occurs at the end of a single production
// rule for SELECT statements.  As soon as the rule that create the 
// limit_opt non-terminal reduces, the SELECT statement rule will also
// reduce.  So there is never a limit_opt non-terminal on the stack 
// except as a transient.  So there is never anything to destroy.
//
//%destructor limit_opt {sqlite3ExprDelete(pParse->db, $$);}
limit_opt(A) ::= .       {A = 0;}
limit_opt(A) ::= LIMIT expr(X).
                         {A = sqlite3PExpr(pParse,TK_LIMIT,X,0);}
limit_opt(A) ::= LIMIT expr(X) OFFSET expr(Y). 
                         {A = sqlite3PExpr(pParse,TK_LIMIT,X,Y);}
limit_opt(A) ::= LIMIT expr(X) COMMA expr(Y). 
                         {A = sqlite3PExpr(pParse,TK_LIMIT,Y,X);}

/////////////////////////// The DELETE statement /////////////////////////////
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W) 
        orderby_opt(O) limit_opt(L). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3DeleteFrom(pParse,X,W,O,L);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3DeleteFrom(pParse,X,W,0,0);
}
%endif

%type where_opt {Expr*}
%destructor where_opt {sqlite3ExprDelete(pParse->db, $$);}

where_opt(A) ::= .                    {A = 0;}
where_opt(A) ::= WHERE expr(X).       {A = X;}

////////////////////////// The UPDATE command ////////////////////////////////
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W) orderby_opt(O) limit_opt(L).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  sqlite3Update(pParse,X,Y,W,R,O,L);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  sqlite3Update(pParse,X,Y,W,R,0,0);
}
%endif

%type setlist {ExprList*}
%destructor setlist {sqlite3ExprListDelete(pParse->db, $$);}

setlist(A) ::= setlist(A) COMMA nm(X) EQ expr(Y). {
  A = sqlite3ExprListAppend(pParse, A, Y);
  sqlite3ExprListSetName(pParse, A, &X, 1);
}
setlist(A) ::= setlist(A) COMMA LP idlist(X) RP EQ expr(Y). {
  A = sqlite3ExprListAppendVector(pParse, A, X, Y);
}
setlist(A) ::= nm(X) EQ expr(Y). {
  A = sqlite3ExprListAppend(pParse, 0, Y);
  sqlite3ExprListSetName(pParse, A, &X, 1);
}
setlist(A) ::= LP idlist(X) RP EQ expr(Y). {
  A = sqlite3ExprListAppendVector(pParse, 0, X, Y);
}

////////////////////////// The INSERT command /////////////////////////////////
//
cmd ::= with(W) insert_cmd(R) INTO fullname(X) idlist_opt(F) select(S). {
  sqlite3WithPush(pParse, W, 1);
  sqlite3Insert(pParse, X, S, F, R);
}
cmd ::= with(W) insert_cmd(R) INTO fullname(X) idlist_opt(F) DEFAULT VALUES.
{
  sqlite3WithPush(pParse, W, 1);
  sqlite3Insert(pParse, X, 0, F, R);
}

%type insert_cmd {int}
insert_cmd(A) ::= INSERT orconf(R).   {A = R;}
insert_cmd(A) ::= REPLACE.            {A = OE_Replace;}

%type idlist_opt {IdList*}
%destructor idlist_opt {sqlite3IdListDelete(pParse->db, $$);}
%type idlist {IdList*}
%destructor idlist {sqlite3IdListDelete(pParse->db, $$);}

idlist_opt(A) ::= .                       {A = 0;}
idlist_opt(A) ::= LP idlist(X) RP.    {A = X;}
idlist(A) ::= idlist(A) COMMA nm(Y).
    {A = sqlite3IdListAppend(pParse->db,A,&Y);}
idlist(A) ::= nm(Y).
    {A = sqlite3IdListAppend(pParse->db,0,&Y); /*A-overwrites-Y*/}

/////////////////////////// Expression Processing /////////////////////////////
//

%type expr {Expr*}
%destructor expr {sqlite3ExprDelete(pParse->db, $$);}
%type term {Expr*}
%destructor term {sqlite3ExprDelete(pParse->db, $$);}

%include {

  /* Construct a new Expr object from a single identifier.  Use the
  ** new Expr to populate pOut.  Set the span of pOut to be the identifier
  ** that created the expression.
  */
  static Expr *tokenExpr(Parse *pParse, int op, Token t){
    Expr *p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr)+t.n+1);
    if( p ){
      memset(p, 0, sizeof(Expr));
      p->op = (u8)op;
      p->flags = EP_Leaf;
      p->iAgg = -1;
      p->u.zToken = (char*)&p[1];
      memcpy(p->u.zToken, t.z, t.n);
      p->u.zToken[t.n] = 0;
      if( sqlite3Isquote(p->u.zToken[0]) ){
        if( p->u.zToken[0]=='"' ) p->flags |= EP_DblQuoted;
        sqlite3Dequote(p->u.zToken);
      }
#if SQLITE_MAX_EXPR_DEPTH>0
      p->nHeight = 1;
#endif  
    }
    return p;
  }
}

expr(A) ::= term(A).
expr(A) ::= LP expr(X) RP. {A = X;}
expr(A) ::= id(X).          {A=tokenExpr(pParse,TK_ID,X); /*A-overwrites-X*/}
expr(A) ::= JOIN_KW(X).     {A=tokenExpr(pParse,TK_ID,X); /*A-overwrites-X*/}
expr(A) ::= nm(X) DOT nm(Y). {
  Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &X, 1);
  Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &Y, 1);
  A = sqlite3PExpr(pParse, TK_DOT, temp1, temp2);
}
expr(A) ::= nm(X) DOT nm(Y) DOT nm(Z). {
  Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &X, 1);
  Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &Y, 1);
  Expr *temp3 = sqlite3ExprAlloc(pParse->db, TK_ID, &Z, 1);
  Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3);
  A = sqlite3PExpr(pParse, TK_DOT, temp1, temp4);
}
term(A) ::= NULL|FLOAT|BLOB(X). {A=tokenExpr(pParse,@X,X); /*A-overwrites-X*/}
term(A) ::= STRING(X).          {A=tokenExpr(pParse,@X,X); /*A-overwrites-X*/}
term(A) ::= INTEGER(X). {
  A = sqlite3ExprAlloc(pParse->db, TK_INTEGER, &X, 1);
}
expr(A) ::= VARIABLE(X).     {
  if( !(X.z[0]=='#' && sqlite3Isdigit(X.z[1])) ){
    u32 n = X.n;
    A = tokenExpr(pParse, TK_VARIABLE, X);
    sqlite3ExprAssignVarNumber(pParse, A, n);
  }else{
    /* When doing a nested parse, one can include terms in an expression
    ** that look like this:   #1 #2 ...  These terms refer to registers
    ** in the virtual machine.  #N is the N-th register. */
    Token t = X; /*A-overwrites-X*/
    assert( t.n>=2 );
    if( pParse->nested==0 ){
      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &t);
      A = 0;
    }else{
      A = sqlite3PExpr(pParse, TK_REGISTER, 0, 0);
      if( A ) sqlite3GetInt32(&t.z[1], &A->iTable);
    }
  }
}
expr(A) ::= expr(A) COLLATE ids(C). {
  A = sqlite3ExprAddCollateToken(pParse, A, &C, 1);
}
%ifndef SQLITE_OMIT_CAST
expr(A) ::= CAST LP expr(E) AS typetoken(T) RP. {
  A = sqlite3ExprAlloc(pParse->db, TK_CAST, &T, 1);
  sqlite3ExprAttachSubtrees(pParse->db, A, E, 0);
}
%endif  SQLITE_OMIT_CAST
expr(A) ::= id(X) LP distinct(D) exprlist(Y) RP. {
  if( Y && Y->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
    sqlite3ErrorMsg(pParse, "too many arguments on function %T", &X);
  }
  A = sqlite3ExprFunction(pParse, Y, &X);
  if( D==SF_Distinct && A ){
    A->flags |= EP_Distinct;
  }
}
expr(A) ::= id(X) LP STAR RP. {
  A = sqlite3ExprFunction(pParse, 0, &X);
}
term(A) ::= CTIME_KW(OP). {
  A = sqlite3ExprFunction(pParse, 0, &OP);
}

expr(A) ::= LP nexprlist(X) COMMA expr(Y) RP. {
  ExprList *pList = sqlite3ExprListAppend(pParse, X, Y);
  A = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);
  if( A ){
    A->x.pList = pList;
  }else{
    sqlite3ExprListDelete(pParse->db, pList);
  }
}

expr(A) ::= expr(A) AND(OP) expr(Y).    {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) OR(OP) expr(Y).     {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) LT|GT|GE|LE(OP) expr(Y).
                                        {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) EQ|NE(OP) expr(Y).  {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) BITAND|BITOR|LSHIFT|RSHIFT(OP) expr(Y).
                                        {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) PLUS|MINUS(OP) expr(Y).
                                        {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) STAR|SLASH|REM(OP) expr(Y).
                                        {A=sqlite3PExpr(pParse,@OP,A,Y);}
expr(A) ::= expr(A) CONCAT(OP) expr(Y). {A=sqlite3PExpr(pParse,@OP,A,Y);}
%type likeop {Token}
likeop(A) ::= LIKE_KW|MATCH(A).
likeop(A) ::= NOT LIKE_KW|MATCH(X). {A=X; A.n|=0x80000000; /*A-overwrite-X*/}
expr(A) ::= expr(A) likeop(OP) expr(Y).  [LIKE_KW]  {
  ExprList *pList;
  int bNot = OP.n & 0x80000000;
  OP.n &= 0x7fffffff;
  pList = sqlite3ExprListAppend(pParse,0, Y);
  pList = sqlite3ExprListAppend(pParse,pList, A);
  A = sqlite3ExprFunction(pParse, pList, &OP);
  if( bNot ) A = sqlite3PExpr(pParse, TK_NOT, A, 0);
  if( A ) A->flags |= EP_InfixFunc;
}
expr(A) ::= expr(A) likeop(OP) expr(Y) ESCAPE expr(E).  [LIKE_KW]  {
  ExprList *pList;
  int bNot = OP.n & 0x80000000;
  OP.n &= 0x7fffffff;
  pList = sqlite3ExprListAppend(pParse,0, Y);
  pList = sqlite3ExprListAppend(pParse,pList, A);
  pList = sqlite3ExprListAppend(pParse,pList, E);
  A = sqlite3ExprFunction(pParse, pList, &OP);
  if( bNot ) A = sqlite3PExpr(pParse, TK_NOT, A, 0);
  if( A ) A->flags |= EP_InfixFunc;
}

expr(A) ::= expr(A) ISNULL|NOTNULL(E).   {A = sqlite3PExpr(pParse,@E,A,0);}
expr(A) ::= expr(A) NOT NULL.    {A = sqlite3PExpr(pParse,TK_NOTNULL,A,0);}

%include {
  /* A routine to convert a binary TK_IS or TK_ISNOT expression into a
  ** unary TK_ISNULL or TK_NOTNULL expression. */
  static void binaryToUnaryIfNull(Parse *pParse, Expr *pY, Expr *pA, int op){
    sqlite3 *db = pParse->db;
    if( pA && pY && pY->op==TK_NULL ){
      pA->op = (u8)op;
      sqlite3ExprDelete(db, pA->pRight);
      pA->pRight = 0;
    }
  }
}

//    expr1 IS expr2
//    expr1 IS NOT expr2
//
// If expr2 is NULL then code as TK_ISNULL or TK_NOTNULL.  If expr2
// is any other expression, code as TK_IS or TK_ISNOT.
// 
expr(A) ::= expr(A) IS expr(Y).     {
  A = sqlite3PExpr(pParse,TK_IS,A,Y);
  binaryToUnaryIfNull(pParse, Y, A, TK_ISNULL);
}
expr(A) ::= expr(A) IS NOT expr(Y). {
  A = sqlite3PExpr(pParse,TK_ISNOT,A,Y);
  binaryToUnaryIfNull(pParse, Y, A, TK_NOTNULL);
}

expr(A) ::= NOT(B) expr(X).  
              {A = sqlite3PExpr(pParse, @B, X, 0);/*A-overwrites-B*/}
expr(A) ::= BITNOT(B) expr(X).
              {A = sqlite3PExpr(pParse, @B, X, 0);/*A-overwrites-B*/}
expr(A) ::= MINUS expr(X). [BITNOT]
              {A = sqlite3PExpr(pParse, TK_UMINUS, X, 0);}
expr(A) ::= PLUS expr(X). [BITNOT]
              {A = sqlite3PExpr(pParse, TK_UPLUS, X, 0);}

%type between_op {int}
between_op(A) ::= BETWEEN.     {A = 0;}
between_op(A) ::= NOT BETWEEN. {A = 1;}
expr(A) ::= expr(A) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
  ExprList *pList = sqlite3ExprListAppend(pParse,0, X);
  pList = sqlite3ExprListAppend(pParse,pList, Y);
  A = sqlite3PExpr(pParse, TK_BETWEEN, A, 0);
  if( A ){
    A->x.pList = pList;
  }else{
    sqlite3ExprListDelete(pParse->db, pList);
  } 
  if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0);
}
%ifndef SQLITE_OMIT_SUBQUERY
  %type in_op {int}
  in_op(A) ::= IN.      {A = 0;}
  in_op(A) ::= NOT IN.  {A = 1;}
  expr(A) ::= expr(A) in_op(N) LP exprlist(Y) RP. [IN] {
    if( Y==0 ){
      /* Expressions of the form
      **
      **      expr1 IN ()
      **      expr1 NOT IN ()
      **
      ** simplify to constants 0 (false) and 1 (true), respectively,
      ** regardless of the value of expr1.
      */
      sqlite3ExprDelete(pParse->db, A);
      A = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[N],1);
    }else if( Y->nExpr==1 ){
      /* Expressions of the form:
      **
      **      expr1 IN (?1)
      **      expr1 NOT IN (?2)
      **
      ** with exactly one value on the RHS can be simplified to something
      ** like this:
      **
      **      expr1 == ?1
      **      expr1 <> ?2
      **
      ** But, the RHS of the == or <> is marked with the EP_Generic flag
      ** so that it may not contribute to the computation of comparison
      ** affinity or the collating sequence to use for comparison.  Otherwise,
      ** the semantics would be subtly different from IN or NOT IN.
      */
      Expr *pRHS = Y->a[0].pExpr;
      Y->a[0].pExpr = 0;
      sqlite3ExprListDelete(pParse->db, Y);
      /* pRHS cannot be NULL because a malloc error would have been detected
      ** before now and control would have never reached this point */
      if( ALWAYS(pRHS) ){
        pRHS->flags &= ~EP_Collate;
        pRHS->flags |= EP_Generic;
      }
      A = sqlite3PExpr(pParse, N ? TK_NE : TK_EQ, A, pRHS);
    }else{
      A = sqlite3PExpr(pParse, TK_IN, A, 0);
      if( A ){
        A->x.pList = Y;
        sqlite3ExprSetHeightAndFlags(pParse, A);
      }else{
        sqlite3ExprListDelete(pParse->db, Y);
      }
      if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0);
    }
  }
  expr(A) ::= LP select(X) RP. {
    A = sqlite3PExpr(pParse, TK_SELECT, 0, 0);
    sqlite3PExprAddSelect(pParse, A, X);
  }
  expr(A) ::= expr(A) in_op(N) LP select(Y) RP.  [IN] {
    A = sqlite3PExpr(pParse, TK_IN, A, 0);
    sqlite3PExprAddSelect(pParse, A, Y);
    if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0);
  }
  expr(A) ::= expr(A) in_op(N) nm(Y) dbnm(Z) paren_exprlist(E). [IN] {
    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&Y,&Z);
    Select *pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0);
    if( E )  sqlite3SrcListFuncArgs(pParse, pSelect ? pSrc : 0, E);
    A = sqlite3PExpr(pParse, TK_IN, A, 0);
    sqlite3PExprAddSelect(pParse, A, pSelect);
    if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0);
  }
  expr(A) ::= EXISTS LP select(Y) RP. {
    Expr *p;
    p = A = sqlite3PExpr(pParse, TK_EXISTS, 0, 0);
    sqlite3PExprAddSelect(pParse, p, Y);
  }
%endif SQLITE_OMIT_SUBQUERY

/* CASE expressions */
expr(A) ::= CASE case_operand(X) case_exprlist(Y) case_else(Z) END. {
  A = sqlite3PExpr(pParse, TK_CASE, X, 0);
  if( A ){
    A->x.pList = Z ? sqlite3ExprListAppend(pParse,Y,Z) : Y;
    sqlite3ExprSetHeightAndFlags(pParse, A);
  }else{
    sqlite3ExprListDelete(pParse->db, Y);
    sqlite3ExprDelete(pParse->db, Z);
  }
}
%type case_exprlist {ExprList*}
%destructor case_exprlist {sqlite3ExprListDelete(pParse->db, $$);}
case_exprlist(A) ::= case_exprlist(A) WHEN expr(Y) THEN expr(Z). {
  A = sqlite3ExprListAppend(pParse,A, Y);
  A = sqlite3ExprListAppend(pParse,A, Z);
}
case_exprlist(A) ::= WHEN expr(Y) THEN expr(Z). {
  A = sqlite3ExprListAppend(pParse,0, Y);
  A = sqlite3ExprListAppend(pParse,A, Z);
}
%type case_else {Expr*}
%destructor case_else {sqlite3ExprDelete(pParse->db, $$);}
case_else(A) ::=  ELSE expr(X).         {A = X;}
case_else(A) ::=  .                     {A = 0;} 
%type case_operand {Expr*}
%destructor case_operand {sqlite3ExprDelete(pParse->db, $$);}
case_operand(A) ::= expr(X).            {A = X; /*A-overwrites-X*/} 
case_operand(A) ::= .                   {A = 0;} 

%type exprlist {ExprList*}
%destructor exprlist {sqlite3ExprListDelete(pParse->db, $$);}
%type nexprlist {ExprList*}
%destructor nexprlist {sqlite3ExprListDelete(pParse->db, $$);}

exprlist(A) ::= nexprlist(A).
exprlist(A) ::= .                            {A = 0;}
nexprlist(A) ::= nexprlist(A) COMMA expr(Y).
    {A = sqlite3ExprListAppend(pParse,A,Y);}
nexprlist(A) ::= expr(Y).
    {A = sqlite3ExprListAppend(pParse,0,Y); /*A-overwrites-Y*/}

%ifndef SQLITE_OMIT_SUBQUERY
/* A paren_exprlist is an optional expression list contained inside
** of parenthesis */
%type paren_exprlist {ExprList*}
%destructor paren_exprlist {sqlite3ExprListDelete(pParse->db, $$);}
paren_exprlist(A) ::= .   {A = 0;}
paren_exprlist(A) ::= LP exprlist(X) RP.  {A = X;}
%endif SQLITE_OMIT_SUBQUERY


///////////////////////////// The CREATE INDEX command ///////////////////////
//
cmd ::= createkw(S) uniqueflag(U) INDEX ifnotexists(NE) nm(X) dbnm(D)
        ON nm(Y) LP sortlist(Z) RP where_opt(W). {
  sqlite3CreateIndex(pParse, &X, &D, 
                     sqlite3SrcListAppend(pParse->db,0,&Y,0), Z, U,
                      &S, W, SQLITE_SO_ASC, NE, SQLITE_IDXTYPE_APPDEF);
}

%type uniqueflag {int}
uniqueflag(A) ::= UNIQUE.  {A = OE_Abort;}
uniqueflag(A) ::= .        {A = OE_None;}


// The eidlist non-terminal (Expression Id List) generates an ExprList
// from a list of identifiers.  The identifier names are in ExprList.a[].zName.
// This list is stored in an ExprList rather than an IdList so that it
// can be easily sent to sqlite3ColumnsExprList().
//
// eidlist is grouped with CREATE INDEX because it used to be the non-terminal
// used for the arguments to an index.  That is just an historical accident.
//
// IMPORTANT COMPATIBILITY NOTE:  Some prior versions of SQLite accepted
// COLLATE clauses and ASC or DESC keywords on ID lists in inappropriate
// places - places that might have been stored in the sqlite_master schema.
// Those extra features were ignored.  But because they might be in some
// (busted) old databases, we need to continue parsing them when loading
// historical schemas.
//
%type eidlist {ExprList*}
%destructor eidlist {sqlite3ExprListDelete(pParse->db, $$);}
%type eidlist_opt {ExprList*}
%destructor eidlist_opt {sqlite3ExprListDelete(pParse->db, $$);}

%include {
  /* Add a single new term to an ExprList that is used to store a
  ** list of identifiers.  Report an error if the ID list contains
  ** a COLLATE clause or an ASC or DESC keyword, except ignore the
  ** error while parsing a legacy schema.
  */
  static ExprList *parserAddExprIdListTerm(
    Parse *pParse,
    ExprList *pPrior,
    Token *pIdToken,
    int hasCollate,
    int sortOrder
  ){
    ExprList *p = sqlite3ExprListAppend(pParse, pPrior, 0);
    if( (hasCollate || sortOrder!=SQLITE_SO_UNDEFINED)
        && pParse->db->init.busy==0
    ){
      sqlite3ErrorMsg(pParse, "syntax error after column name \"%.*s\"",
                         pIdToken->n, pIdToken->z);
    }
    sqlite3ExprListSetName(pParse, p, pIdToken, 1);
    return p;
  }
} // end %include

eidlist_opt(A) ::= .                         {A = 0;}
eidlist_opt(A) ::= LP eidlist(X) RP.         {A = X;}
eidlist(A) ::= eidlist(A) COMMA nm(Y) collate(C) sortorder(Z).  {
  A = parserAddExprIdListTerm(pParse, A, &Y, C, Z);
}
eidlist(A) ::= nm(Y) collate(C) sortorder(Z). {
  A = parserAddExprIdListTerm(pParse, 0, &Y, C, Z); /*A-overwrites-Y*/
}

%type collate {int}
collate(C) ::= .              {C = 0;}
collate(C) ::= COLLATE ids.   {C = 1;}


///////////////////////////// The DROP INDEX command /////////////////////////
//
cmd ::= DROP INDEX ifexists(E) fullname(X).   {sqlite3DropIndex(pParse, X, E);}

///////////////////////////// The VACUUM command /////////////////////////////
//
%ifndef SQLITE_OMIT_VACUUM
%ifndef SQLITE_OMIT_ATTACH
cmd ::= VACUUM.                {sqlite3Vacuum(pParse,0);}
cmd ::= VACUUM nm(X).          {sqlite3Vacuum(pParse,&X);}
%endif  SQLITE_OMIT_ATTACH
%endif  SQLITE_OMIT_VACUUM

///////////////////////////// The PRAGMA command /////////////////////////////
//
%ifndef SQLITE_OMIT_PRAGMA
cmd ::= PRAGMA nm(X) dbnm(Z).                {sqlite3Pragma(pParse,&X,&Z,0,0);}
cmd ::= PRAGMA nm(X) dbnm(Z) EQ nmnum(Y).    {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
cmd ::= PRAGMA nm(X) dbnm(Z) LP nmnum(Y) RP. {sqlite3Pragma(pParse,&X,&Z,&Y,0);}
cmd ::= PRAGMA nm(X) dbnm(Z) EQ minus_num(Y). 
                                             {sqlite3Pragma(pParse,&X,&Z,&Y,1);}
cmd ::= PRAGMA nm(X) dbnm(Z) LP minus_num(Y) RP.
                                             {sqlite3Pragma(pParse,&X,&Z,&Y,1);}

nmnum(A) ::= plus_num(A).
nmnum(A) ::= nm(A).
nmnum(A) ::= ON(A).
nmnum(A) ::= DELETE(A).
nmnum(A) ::= DEFAULT(A).
%endif SQLITE_OMIT_PRAGMA
%token_class number INTEGER|FLOAT.
plus_num(A) ::= PLUS number(X).       {A = X;}
plus_num(A) ::= number(A).
minus_num(A) ::= MINUS number(X).     {A = X;}
//////////////////////////// The CREATE TRIGGER command /////////////////////

%ifndef SQLITE_OMIT_TRIGGER

cmd ::= createkw trigger_decl(A) BEGIN trigger_cmd_list(S) END(Z). {
  Token all;
  all.z = A.z;
  all.n = (int)(Z.z - A.z) + Z.n;
  sqlite3FinishTrigger(pParse, S, &all);
}

trigger_decl(A) ::= temp(T) TRIGGER ifnotexists(NOERR) nm(B) dbnm(Z) 
                    trigger_time(C) trigger_event(D)
                    ON fullname(E) foreach_clause when_clause(G). {
  sqlite3BeginTrigger(pParse, &B, &Z, C, D.a, D.b, E, G, T, NOERR);
  A = (Z.n==0?B:Z); /*A-overwrites-T*/
}

%type trigger_time {int}
trigger_time(A) ::= BEFORE|AFTER(X).  { A = @X; /*A-overwrites-X*/ }
trigger_time(A) ::= INSTEAD OF.  { A = TK_INSTEAD;}
trigger_time(A) ::= .            { A = TK_BEFORE; }

%type trigger_event {struct TrigEvent}
%destructor trigger_event {sqlite3IdListDelete(pParse->db, $$.b);}
trigger_event(A) ::= DELETE|INSERT(X).   {A.a = @X; /*A-overwrites-X*/ A.b = 0;}
trigger_event(A) ::= UPDATE(X).          {A.a = @X; /*A-overwrites-X*/ A.b = 0;}
trigger_event(A) ::= UPDATE OF idlist(X).{A.a = TK_UPDATE; A.b = X;}

foreach_clause ::= .
foreach_clause ::= FOR EACH ROW.

%type when_clause {Expr*}
%destructor when_clause {sqlite3ExprDelete(pParse->db, $$);}
when_clause(A) ::= .             { A = 0; }
when_clause(A) ::= WHEN expr(X). { A = X; }

%type trigger_cmd_list {TriggerStep*}
%destructor trigger_cmd_list {sqlite3DeleteTriggerStep(pParse->db, $$);}
trigger_cmd_list(A) ::= trigger_cmd_list(A) trigger_cmd(X) SEMI. {
  assert( A!=0 );
  A->pLast->pNext = X;
  A->pLast = X;
}
trigger_cmd_list(A) ::= trigger_cmd(A) SEMI. { 
  assert( A!=0 );
  A->pLast = A;
}

// Disallow qualified table names on INSERT, UPDATE, and DELETE statements
// within a trigger.  The table to INSERT, UPDATE, or DELETE is always in 
// the same database as the table that the trigger fires on.
//
%type trnm {Token}
trnm(A) ::= nm(A).
trnm(A) ::= nm DOT nm(X). {
  A = X;
  sqlite3ErrorMsg(pParse, 
        "qualified table names are not allowed on INSERT, UPDATE, and DELETE "
        "statements within triggers");
}

// Disallow the INDEX BY and NOT INDEXED clauses on UPDATE and DELETE
// statements within triggers.  We make a specific error message for this
// since it is an exception to the default grammar rules.
//
tridxby ::= .
tridxby ::= INDEXED BY nm. {
  sqlite3ErrorMsg(pParse,
        "the INDEXED BY clause is not allowed on UPDATE or DELETE statements "
        "within triggers");
}
tridxby ::= NOT INDEXED. {
  sqlite3ErrorMsg(pParse,
        "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements "
        "within triggers");
}



%type trigger_cmd {TriggerStep*}
%destructor trigger_cmd {sqlite3DeleteTriggerStep(pParse->db, $$);}
// UPDATE 
trigger_cmd(A) ::=
   UPDATE(B) orconf(R) trnm(X) tridxby SET setlist(Y) where_opt(Z) scanpt(E).  
   {A = sqlite3TriggerUpdateStep(pParse->db, &X, Y, Z, R, B.z, E);}

// INSERT
trigger_cmd(A) ::= scanpt(B) insert_cmd(R) INTO
                      trnm(X) idlist_opt(F) select(S) scanpt(Z).
   {A = sqlite3TriggerInsertStep(pParse->db,&X,F,S,R,B,Z);/*A-overwrites-R*/}

// DELETE
trigger_cmd(A) ::= DELETE(B) FROM trnm(X) tridxby where_opt(Y) scanpt(E).
   {A = sqlite3TriggerDeleteStep(pParse->db, &X, Y, B.z, E);}

// SELECT
trigger_cmd(A) ::= scanpt(B) select(X) scanpt(E).
   {A = sqlite3TriggerSelectStep(pParse->db, X, B, E); /*A-overwrites-X*/}

// The special RAISE expression that may occur in trigger programs
expr(A) ::= RAISE LP IGNORE RP.  {
  A = sqlite3PExpr(pParse, TK_RAISE, 0, 0); 
  if( A ){
    A->affinity = OE_Ignore;
  }
}
expr(A) ::= RAISE LP raisetype(T) COMMA nm(Z) RP.  {
  A = sqlite3ExprAlloc(pParse->db, TK_RAISE, &Z, 1); 
  if( A ) {
    A->affinity = (char)T;
  }
}
%endif  !SQLITE_OMIT_TRIGGER

%type raisetype {int}
raisetype(A) ::= ROLLBACK.  {A = OE_Rollback;}
raisetype(A) ::= ABORT.     {A = OE_Abort;}
raisetype(A) ::= FAIL.      {A = OE_Fail;}


////////////////////////  DROP TRIGGER statement //////////////////////////////
%ifndef SQLITE_OMIT_TRIGGER
cmd ::= DROP TRIGGER ifexists(NOERR) fullname(X). {
  sqlite3DropTrigger(pParse,X,NOERR);
}
%endif  !SQLITE_OMIT_TRIGGER

//////////////////////// ATTACH DATABASE file AS name /////////////////////////
%ifndef SQLITE_OMIT_ATTACH
cmd ::= ATTACH database_kw_opt expr(F) AS expr(D) key_opt(K). {
  sqlite3Attach(pParse, F, D, K);
}
cmd ::= DETACH database_kw_opt expr(D). {
  sqlite3Detach(pParse, D);
}

%type key_opt {Expr*}
%destructor key_opt {sqlite3ExprDelete(pParse->db, $$);}
key_opt(A) ::= .                     { A = 0; }
key_opt(A) ::= KEY expr(X).          { A = X; }

database_kw_opt ::= DATABASE.
database_kw_opt ::= .
%endif SQLITE_OMIT_ATTACH

////////////////////////// REINDEX collation //////////////////////////////////
%ifndef SQLITE_OMIT_REINDEX
cmd ::= REINDEX.                {sqlite3Reindex(pParse, 0, 0);}
cmd ::= REINDEX nm(X) dbnm(Y).  {sqlite3Reindex(pParse, &X, &Y);}
%endif  SQLITE_OMIT_REINDEX

/////////////////////////////////// ANALYZE ///////////////////////////////////
%ifndef SQLITE_OMIT_ANALYZE
cmd ::= ANALYZE.                {sqlite3Analyze(pParse, 0, 0);}
cmd ::= ANALYZE nm(X) dbnm(Y).  {sqlite3Analyze(pParse, &X, &Y);}
%endif

//////////////////////// ALTER TABLE table ... ////////////////////////////////
%ifndef SQLITE_OMIT_ALTERTABLE
cmd ::= ALTER TABLE fullname(X) RENAME TO nm(Z). {
  sqlite3AlterRenameTable(pParse,X,&Z);
}
cmd ::= ALTER TABLE add_column_fullname
        ADD kwcolumn_opt columnname(Y) carglist. {
  Y.n = (int)(pParse->sLastToken.z-Y.z) + pParse->sLastToken.n;
  sqlite3AlterFinishAddColumn(pParse, &Y);
}
add_column_fullname ::= fullname(X). {
  disableLookaside(pParse);
  sqlite3AlterBeginAddColumn(pParse, X);
}
kwcolumn_opt ::= .
kwcolumn_opt ::= COLUMNKW.
%endif  SQLITE_OMIT_ALTERTABLE

//////////////////////// CREATE VIRTUAL TABLE ... /////////////////////////////
%ifndef SQLITE_OMIT_VIRTUALTABLE
cmd ::= create_vtab.                       {sqlite3VtabFinishParse(pParse,0);}
cmd ::= create_vtab LP vtabarglist RP(X).  {sqlite3VtabFinishParse(pParse,&X);}
create_vtab ::= createkw VIRTUAL TABLE ifnotexists(E)
                nm(X) dbnm(Y) USING nm(Z). {
    sqlite3VtabBeginParse(pParse, &X, &Y, &Z, E);
}
vtabarglist ::= vtabarg.
vtabarglist ::= vtabarglist COMMA vtabarg.
vtabarg ::= .                       {sqlite3VtabArgInit(pParse);}
vtabarg ::= vtabarg vtabargtoken.
vtabargtoken ::= ANY(X).            {sqlite3VtabArgExtend(pParse,&X);}
vtabargtoken ::= lp anylist RP(X).  {sqlite3VtabArgExtend(pParse,&X);}
lp ::= LP(X).                       {sqlite3VtabArgExtend(pParse,&X);}
anylist ::= .
anylist ::= anylist LP anylist RP.
anylist ::= anylist ANY.
%endif  SQLITE_OMIT_VIRTUALTABLE


//////////////////////// COMMON TABLE EXPRESSIONS ////////////////////////////
%type with {With*}
%type wqlist {With*}
%destructor with {sqlite3WithDelete(pParse->db, $$);}
%destructor wqlist {sqlite3WithDelete(pParse->db, $$);}

with(A) ::= . {A = 0;}
%ifndef SQLITE_OMIT_CTE
with(A) ::= WITH wqlist(W).              { A = W; }
with(A) ::= WITH RECURSIVE wqlist(W).    { A = W; }

wqlist(A) ::= nm(X) eidlist_opt(Y) AS LP select(Z) RP. {
  A = sqlite3WithAdd(pParse, 0, &X, Y, Z); /*A-overwrites-X*/
}
wqlist(A) ::= wqlist(A) COMMA nm(X) eidlist_opt(Y) AS LP select(Z) RP. {
  A = sqlite3WithAdd(pParse, A, &X, Y, Z);
}
%endif  SQLITE_OMIT_CTE