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Overview
Comment:Make the result of an IN or NOT IN expression with an empty set on the right-hand side always either false or true, respectively, even if the left-hand side is NULL. Ticket [80e031a00f45dc]
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SHA1: c288ac644d0bfda2b9bc204dc86df8e74d4f6843
User & Date: drh 2010-07-14 18:24:06.000
References
2010-07-14
20:23
The expression list on the RHS of an IN operator can no longer be empty because an empty expression list is now optimized out by changes in check-in [c288ac644d0bf]. Therefore add ALWAYS() macros around tests for the expression list being non-empty. (check-in: fd130ae56c user: drh tags: trunk)
Context
2010-07-14
19:31
Additional test cases and evidence marks for the empty RHS bug on the IN operator - ticket [80e031a00f45dca877] (check-in: 6851c517ac user: drh tags: trunk)
18:24
Make the result of an IN or NOT IN expression with an empty set on the right-hand side always either false or true, respectively, even if the left-hand side is NULL. Ticket [80e031a00f45dc] (check-in: c288ac644d user: drh tags: trunk)
18:10
Fix an assert() failure in wal2.test caused by messing with the contents of shared memory. (check-in: 9f452514d9 user: dan tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/expr.c.
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    default: {
      /* If this has to be a scalar SELECT.  Generate code to put the
      ** value of this select in a memory cell and record the number
      ** of the memory cell in iColumn.  If this is an EXISTS, write
      ** an integer 0 (not exists) or 1 (exists) into a memory cell
      ** and record that memory cell in iColumn.
      */
      static const Token one = { "1", 1 };  /* Token for literal value 1 */
      Select *pSel;                         /* SELECT statement to encode */
      SelectDest dest;                      /* How to deal with SELECt result */

      testcase( pExpr->op==TK_EXISTS );
      testcase( pExpr->op==TK_SELECT );
      assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );

      assert( ExprHasProperty(pExpr, EP_xIsSelect) );
      pSel = pExpr->x.pSelect;
      sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
      if( pExpr->op==TK_SELECT ){
        dest.eDest = SRT_Mem;
        sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
        VdbeComment((v, "Init EXISTS result"));
      }
      sqlite3ExprDelete(pParse->db, pSel->pLimit);
      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);

      if( sqlite3Select(pParse, pSel, &dest) ){
        return 0;
      }
      rReg = dest.iParm;
      ExprSetIrreducible(pExpr);
      break;
    }







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    default: {
      /* If this has to be a scalar SELECT.  Generate code to put the
      ** value of this select in a memory cell and record the number
      ** of the memory cell in iColumn.  If this is an EXISTS, write
      ** an integer 0 (not exists) or 1 (exists) into a memory cell
      ** and record that memory cell in iColumn.
      */

      Select *pSel;                         /* SELECT statement to encode */
      SelectDest dest;                      /* How to deal with SELECt result */

      testcase( pExpr->op==TK_EXISTS );
      testcase( pExpr->op==TK_SELECT );
      assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );

      assert( ExprHasProperty(pExpr, EP_xIsSelect) );
      pSel = pExpr->x.pSelect;
      sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
      if( pExpr->op==TK_SELECT ){
        dest.eDest = SRT_Mem;
        sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
        VdbeComment((v, "Init EXISTS result"));
      }
      sqlite3ExprDelete(pParse->db, pSel->pLimit);
      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
                                  &sqlite3IntTokens[1]);
      if( sqlite3Select(pParse, pSel, &dest) ){
        return 0;
      }
      rReg = dest.iParm;
      ExprSetIrreducible(pExpr);
      break;
    }
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  affinity = comparisonAffinity(pExpr);

  /* Code the LHS, the <expr> from "<expr> IN (...)".
  */
  sqlite3ExprCachePush(pParse);
  r1 = sqlite3GetTempReg(pParse);
  sqlite3ExprCode(pParse, pExpr->pLeft, r1);







  sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);







  if( eType==IN_INDEX_ROWID ){
    /* In this case, the RHS is the ROWID of table b-tree
    */
    sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
    sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
  }else{







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  affinity = comparisonAffinity(pExpr);

  /* Code the LHS, the <expr> from "<expr> IN (...)".
  */
  sqlite3ExprCachePush(pParse);
  r1 = sqlite3GetTempReg(pParse);
  sqlite3ExprCode(pParse, pExpr->pLeft, r1);

  /* If the LHS is NULL, then the result is either false or NULL depending
  ** on whether the RHS is empty or not, respectively.
  */
  if( destIfNull==destIfFalse ){
    /* Shortcut for the common case where the false and NULL outcomes are
    ** the same. */
    sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);
  }else{
    int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1);
    sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
    sqlite3VdbeJumpHere(v, addr1);
  }

  if( eType==IN_INDEX_ROWID ){
    /* In this case, the RHS is the ROWID of table b-tree
    */
    sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
    sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
  }else{
Changes to src/global.c.
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/*
** Hash table for global functions - functions common to all
** database connections.  After initialization, this table is
** read-only.
*/
SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;










/*
** The value of the "pending" byte must be 0x40000000 (1 byte past the
** 1-gibabyte boundary) in a compatible database.  SQLite never uses
** the database page that contains the pending byte.  It never attempts
** to read or write that page.  The pending byte page is set assign
** for use by the VFS layers as space for managing file locks.







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/*
** Hash table for global functions - functions common to all
** database connections.  After initialization, this table is
** read-only.
*/
SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;

/*
** Constant tokens for values 0 and 1.
*/
const Token sqlite3IntTokens[] = {
   { "0", 1 },
   { "1", 1 }
};


/*
** The value of the "pending" byte must be 0x40000000 (1 byte past the
** 1-gibabyte boundary) in a compatible database.  SQLite never uses
** the database page that contains the pending byte.  It never attempts
** to read or write that page.  The pending byte page is set assign
** for use by the VFS layers as space for managing file locks.
Changes to src/parse.y.
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  A.zEnd = Y.zEnd;
}
%ifndef SQLITE_OMIT_SUBQUERY
  %type in_op {int}
  in_op(A) ::= IN.      {A = 0;}
  in_op(A) ::= NOT IN.  {A = 1;}
  expr(A) ::= expr(X) in_op(N) LP exprlist(Y) RP(E). [IN] {












    A.pExpr = sqlite3PExpr(pParse, TK_IN, X.pExpr, 0, 0);
    if( A.pExpr ){
      A.pExpr->x.pList = Y;
      sqlite3ExprSetHeight(pParse, A.pExpr);
    }else{
      sqlite3ExprListDelete(pParse->db, Y);
    }
    if( N ) A.pExpr = sqlite3PExpr(pParse, TK_NOT, A.pExpr, 0, 0);

    A.zStart = X.zStart;
    A.zEnd = &E.z[E.n];
  }
  expr(A) ::= LP(B) select(X) RP(E). {
    A.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
    if( A.pExpr ){
      A.pExpr->x.pSelect = X;







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  A.zEnd = Y.zEnd;
}
%ifndef SQLITE_OMIT_SUBQUERY
  %type in_op {int}
  in_op(A) ::= IN.      {A = 0;}
  in_op(A) ::= NOT IN.  {A = 1;}
  expr(A) ::= expr(X) in_op(N) LP exprlist(Y) RP(E). [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.
      //
      A.pExpr = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &sqlite3IntTokens[N]);
      sqlite3ExprDelete(pParse->db, X.pExpr);
    }else{
      A.pExpr = sqlite3PExpr(pParse, TK_IN, X.pExpr, 0, 0);
      if( A.pExpr ){
        A.pExpr->x.pList = Y;
        sqlite3ExprSetHeight(pParse, A.pExpr);
      }else{
        sqlite3ExprListDelete(pParse->db, Y);
      }
      if( N ) A.pExpr = sqlite3PExpr(pParse, TK_NOT, A.pExpr, 0, 0);
    }
    A.zStart = X.zStart;
    A.zEnd = &E.z[E.n];
  }
  expr(A) ::= LP(B) select(X) RP(E). {
    A.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
    if( A.pExpr ){
      A.pExpr->x.pSelect = X;
Changes to src/sqliteInt.h.
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#endif
int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION
extern const unsigned char sqlite3OpcodeProperty[];
extern const unsigned char sqlite3UpperToLower[];
extern const unsigned char sqlite3CtypeMap[];

extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
#ifndef SQLITE_OMIT_WSD
extern int sqlite3PendingByte;
#endif
#endif
void sqlite3RootPageMoved(Db*, int, int);







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#endif
int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
#ifndef SQLITE_AMALGAMATION
extern const unsigned char sqlite3OpcodeProperty[];
extern const unsigned char sqlite3UpperToLower[];
extern const unsigned char sqlite3CtypeMap[];
extern const Token sqlite3IntTokens[];
extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
#ifndef SQLITE_OMIT_WSD
extern int sqlite3PendingByte;
#endif
#endif
void sqlite3RootPageMoved(Db*, int, int);
Added test/tkt-80e031a00f.test.


































































































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# 2010 July 14
#
# 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 implements regression tests for SQLite library. Specifically,
# it tests that ticket [80e031a00f45dca877ed92b225209cfa09280f4f] has been
# resolved.  That ticket is about IN and NOT IN operators with empty-set
# right-hand sides.  Such expressions should always return TRUE or FALSE
# even if the left-hand side is NULL.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/malloc_common.tcl

do_execsql_test tkt-80e031a00f.1 {SELECT 1 IN ()} 0
do_execsql_test tkt-80e031a00f.2 {SELECT 1 NOT IN ()} 1
do_execsql_test tkt-80e031a00f.3 {SELECT null IN ()} 0
do_execsql_test tkt-80e031a00f.4 {SELECT null NOT IN ()} 1
do_execsql_test tkt-80e031a00f.5 {
  CREATE TABLE t1(x);
  SELECT 1 IN t1;
} 0
do_execsql_test tkt-80e031a00f.6 {SELECT 1 NOT IN t1} 1
do_execsql_test tkt-80e031a00f.7 {SELECT null IN t1} 0
do_execsql_test tkt-80e031a00f.8 {SELECT null NOT IN t1} 1
do_execsql_test tkt-80e031a00f.9 {
  CREATE TABLE t2(y INTEGER PRIMARY KEY);
  SELECT 1 IN t2;
} 0
do_execsql_test tkt-80e031a00f.10 {SELECT 1 NOT IN t2} 1
do_execsql_test tkt-80e031a00f.11 {SELECT null IN t2} 0
do_execsql_test tkt-80e031a00f.12 {SELECT null NOT IN t2} 1
do_execsql_test tkt-80e031a00f.9 {
  CREATE TABLE t3(z INT UNIQUE);
  SELECT 1 IN t3;
} 0
do_execsql_test tkt-80e031a00f.13 {SELECT 1 NOT IN t3} 1
do_execsql_test tkt-80e031a00f.14 {SELECT null IN t3} 0
do_execsql_test tkt-80e031a00f.15 {SELECT null NOT IN t3} 1

finish_test