** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
  int op;
  pExpr = sqlite3ExprSkipCollate(pExpr);

  op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
  }
#ifndef SQLITE_OMIT_CAST
  if( op==TK_CAST ){
................................................................................
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken.   Return a pointer to a new Expr node that
** implements the COLLATE operator.
**
** If a memory allocation error occurs, that fact is recorded in pParse->db
** and the pExpr parameter is returned unchanged.
*/
Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr *pExpr, Token *pCollName){




  if( pCollName->n>0 ){
    Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, 1);
    if( pNew ){
      pNew->pLeft = pExpr;
      pNew->flags |= EP_Collate|EP_Skip;
      pExpr = pNew;
    }
................................................................................
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;
  CollSeq *pColl = 0;
  Expr *p = pExpr;
  while( p ){
    int op = p->op;

    if( op==TK_CAST || op==TK_UPLUS ){
      p = p->pLeft;
      continue;
    }
    if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){
      pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
      break;
................................................................................
    u32 savedNQueryLoop = pParse->nQueryLoop;
    int rMayHaveNull = 0;
    eType = IN_INDEX_EPH;
    if( prNotFound ){
      *prNotFound = rMayHaveNull = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    }else{
      testcase( pParse->nQueryLoop>0 );
      pParse->nQueryLoop = 0;
      if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
        eType = IN_INDEX_ROWID;
      }
    }
    sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
    pParse->nQueryLoop = savedNQueryLoop;

** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
  int op;
  pExpr = sqlite3ExprSkipCollate(pExpr);
  if( pExpr->flags & EP_Generic ) return SQLITE_AFF_NONE;
  op = pExpr->op;
  if( op==TK_SELECT ){
    assert( pExpr->flags&EP_xIsSelect );
    return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
  }
#ifndef SQLITE_OMIT_CAST
  if( op==TK_CAST ){
................................................................................
** Set the collating sequence for expression pExpr to be the collating
** sequence named by pToken.   Return a pointer to a new Expr node that
** implements the COLLATE operator.
**
** If a memory allocation error occurs, that fact is recorded in pParse->db
** and the pExpr parameter is returned unchanged.
*/
Expr *sqlite3ExprAddCollateToken(
  Parse *pParse,           /* Parsing context */
  Expr *pExpr,             /* Add the "COLLATE" clause to this expression */
  const Token *pCollName   /* Name of collating sequence */
){
  if( pCollName->n>0 ){
    Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, 1);
    if( pNew ){
      pNew->pLeft = pExpr;
      pNew->flags |= EP_Collate|EP_Skip;
      pExpr = pNew;
    }
................................................................................
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;
  CollSeq *pColl = 0;
  Expr *p = pExpr;
  while( p ){
    int op = p->op;
    if( p->flags & EP_Generic ) break;
    if( op==TK_CAST || op==TK_UPLUS ){
      p = p->pLeft;
      continue;
    }
    if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){
      pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
      break;
................................................................................
    u32 savedNQueryLoop = pParse->nQueryLoop;
    int rMayHaveNull = 0;
    eType = IN_INDEX_EPH;
    if( prNotFound ){
      *prNotFound = rMayHaveNull = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
    }else{

      pParse->nQueryLoop = 0;
      if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
        eType = IN_INDEX_ROWID;
      }
    }
    sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
    pParse->nQueryLoop = savedNQueryLoop;

      **      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);

      **      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 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.pExpr = sqlite3PExpr(pParse, N ? TK_NE : TK_EQ, X.pExpr, pRHS, 0);
    }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);

static void explain_data_prepare(struct callback_data *p, sqlite3_stmt *pSql){
  const char *zSql;               /* The text of the SQL statement */
  const char *z;                  /* Used to check if this is an EXPLAIN */
  int *abYield = 0;               /* True if op is an OP_Yield */
  int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
  int iOp;                        /* Index of operation in p->aiIndent[] */

  const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext", 0 };

  const char *azYield[] = { "Yield", "SeekLt", "SeekGt", "RowSetRead", "Rewind", 0 };
  const char *azGoto[] = { "Goto", 0 };

  /* Try to figure out if this is really an EXPLAIN statement. If this
  ** cannot be verified, return early.  */
  zSql = sqlite3_sql(pSql);
  if( zSql==0 ) return;

static void explain_data_prepare(struct callback_data *p, sqlite3_stmt *pSql){
  const char *zSql;               /* The text of the SQL statement */
  const char *z;                  /* Used to check if this is an EXPLAIN */
  int *abYield = 0;               /* True if op is an OP_Yield */
  int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
  int iOp;                        /* Index of operation in p->aiIndent[] */

  const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext",
                           "NextIfOpen", "PrevIfOpen", 0 };
  const char *azYield[] = { "Yield", "SeekLt", "SeekGt", "RowSetRead", "Rewind", 0 };
  const char *azGoto[] = { "Goto", 0 };

  /* Try to figure out if this is really an EXPLAIN statement. If this
  ** cannot be verified, return early.  */
  zSql = sqlite3_sql(pSql);
  if( zSql==0 ) return;

#define EP_Agg       0x000002 /* Contains one or more aggregate functions */
#define EP_Resolved  0x000004 /* IDs have been resolved to COLUMNs */
#define EP_Error     0x000008 /* Expression contains one or more errors */
#define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
#define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
#define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
#define EP_Collate   0x000100 /* Tree contains a TK_COLLATE opeartor */
      /* unused      0x000200 */
#define EP_IntValue  0x000400 /* Integer value contained in u.iValue */
#define EP_xIsSelect 0x000800 /* x.pSelect is valid (otherwise x.pList is) */
#define EP_Skip      0x001000 /* COLLATE, AS, or UNLIKELY */
#define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */
#define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
#define EP_Static    0x008000 /* Held in memory not obtained from malloc() */
#define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
................................................................................
#endif

const char *sqlite3ErrStr(int);
int sqlite3ReadSchema(Parse *pParse);
CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, Token*);
Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
Expr *sqlite3ExprSkipCollate(Expr*);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3CheckObjectName(Parse *, const char *);
void sqlite3VdbeSetChanges(sqlite3 *, int);
int sqlite3AddInt64(i64*,i64);
int sqlite3SubInt64(i64*,i64);

#define EP_Agg       0x000002 /* Contains one or more aggregate functions */
#define EP_Resolved  0x000004 /* IDs have been resolved to COLUMNs */
#define EP_Error     0x000008 /* Expression contains one or more errors */
#define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
#define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
#define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
#define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */
#define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */
#define EP_IntValue  0x000400 /* Integer value contained in u.iValue */
#define EP_xIsSelect 0x000800 /* x.pSelect is valid (otherwise x.pList is) */
#define EP_Skip      0x001000 /* COLLATE, AS, or UNLIKELY */
#define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */
#define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
#define EP_Static    0x008000 /* Held in memory not obtained from malloc() */
#define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
................................................................................
#endif

const char *sqlite3ErrStr(int);
int sqlite3ReadSchema(Parse *pParse);
CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*);
Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
Expr *sqlite3ExprSkipCollate(Expr*);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3CheckObjectName(Parse *, const char *);
void sqlite3VdbeSetChanges(sqlite3 *, int);
int sqlite3AddInt64(i64*,i64);
int sqlite3SubInt64(i64*,i64);

        **
        ** Alternatively, if pIter2 contains the smaller of the two values,
        ** set aTree[i] to its index and update pIter1. If vdbeSorterCompare()
        ** was actually called above, then pSorter->pUnpacked now contains
        ** a value equivalent to pIter2. So set pKey2 to NULL to prevent
        ** vdbeSorterCompare() from decoding pIter2 again.  */
        if( iRes<=0 ){
          pSorter->aTree[i] = (pIter1 - pSorter->aIter);
          pIter2 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
          pKey2 = pIter2->aKey;
        }else{
          if( pIter1->pFile ) pKey2 = 0;
          pSorter->aTree[i] = (pIter2 - pSorter->aIter);
          pIter1 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
        }

      }
      *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
    }
  }else{

        **
        ** Alternatively, if pIter2 contains the smaller of the two values,
        ** set aTree[i] to its index and update pIter1. If vdbeSorterCompare()
        ** was actually called above, then pSorter->pUnpacked now contains
        ** a value equivalent to pIter2. So set pKey2 to NULL to prevent
        ** vdbeSorterCompare() from decoding pIter2 again.  */
        if( iRes<=0 ){
          pSorter->aTree[i] = (int)(pIter1 - pSorter->aIter);
          pIter2 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
          pKey2 = pIter2->aKey;
        }else{
          if( pIter1->pFile ) pKey2 = 0;
          pSorter->aTree[i] = (int)(pIter2 - pSorter->aIter);
          pIter1 = &pSorter->aIter[ pSorter->aTree[i ^ 0x0001] ];
        }

      }
      *pbEof = (pSorter->aIter[pSorter->aTree[1]].pFile==0);
    }
  }else{

      pLevel->op = OP_Noop;
    }else if( bRev ){
      pLevel->op = OP_Prev;
    }else{
      pLevel->op = OP_Next;
    }
    pLevel->p1 = iIdxCur;
    assert( (WHERE_UNQ_WANTED>>16)==1 );
    pLevel->p3 = (pLoop->wsFlags>>16)&1;
    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
    }else{
      assert( pLevel->p5==0 );
    }
  }else

................................................................................
      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
        nIn = 46;  assert( 46==sqlite3LogEst(25) );
      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
        /* "x IN (value, value, ...)" */
        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
      }


      pNew->rRun += nIn;
      pNew->u.btree.nEq++;
      pNew->nOut = nRowEst + nInMul + nIn;
    }else if( pTerm->eOperator & (WO_EQ) ){
      assert(
        (pNew->wsFlags & (WHERE_COLUMN_NULL|WHERE_COLUMN_IN|WHERE_SKIPSCAN))!=0
        || nInMul==0

      pLevel->op = OP_Noop;
    }else if( bRev ){
      pLevel->op = OP_Prev;
    }else{
      pLevel->op = OP_Next;
    }
    pLevel->p1 = iIdxCur;

    pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
    }else{
      assert( pLevel->p5==0 );
    }
  }else

................................................................................
      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
        nIn = 46;  assert( 46==sqlite3LogEst(25) );
      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
        /* "x IN (value, value, ...)" */
        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
      }
      assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
                        ** changes "x IN (?)" into "x=?". */
      pNew->rRun += nIn;
      pNew->u.btree.nEq++;
      pNew->nOut = nRowEst + nInMul + nIn;
    }else if( pTerm->eOperator & (WO_EQ) ){
      assert(
        (pNew->wsFlags & (WHERE_COLUMN_NULL|WHERE_COLUMN_IN|WHERE_SKIPSCAN))!=0
        || nInMul==0

} {}
do_test in4-3.11 {
  execsql { SELECT * FROM t3 WHERE x IN (1, 2) OR y IN ()}
} {1 1 1}
do_test in4-3.12 {
  execsql { SELECT * FROM t3 WHERE x IN (1, 2) AND y IN ()}
} {}


















































































































































































finish_test

} {}
do_test in4-3.11 {
  execsql { SELECT * FROM t3 WHERE x IN (1, 2) OR y IN ()}
} {1 1 1}
do_test in4-3.12 {
  execsql { SELECT * FROM t3 WHERE x IN (1, 2) AND y IN ()}
} {}

# Tests for "... IN (?)" and "... NOT IN (?)".  In other words, tests
# for when the RHS of IN is a single expression.  This should work the
# same as the == and <> operators.
#
do_execsql_test in4-3.21 {
  SELECT * FROM t3 WHERE x=10 AND y IN (10);
} {10 10 10}
do_execsql_test in4-3.22 {
  SELECT * FROM t3 WHERE x IN (10) AND y=10;
} {10 10 10}
do_execsql_test in4-3.23 {
  SELECT * FROM t3 WHERE x IN (10) AND y IN (10);
} {10 10 10}
do_execsql_test in4-3.24 {
  SELECT * FROM t3 WHERE x=1 AND y NOT IN (10);
} {1 1 1}
do_execsql_test in4-3.25 {
  SELECT * FROM t3 WHERE x  NOT IN (10) AND y=1;
} {1 1 1}
do_execsql_test in4-3.26 {
  SELECT * FROM t3 WHERE x NOT IN (10) AND y NOT IN (10);
} {1 1 1}

# The query planner recognizes that "x IN (?)" only generates a
# single match and can use this information to optimize-out ORDER BY
# clauses.
#
do_execsql_test in4-3.31 {
  DROP INDEX t3i1;
  CREATE UNIQUE INDEX t3xy ON t3(x,y);

  SELECT *, '|' FROM t3 A, t3 B
   WHERE A.x=10 AND A.y IN (10)
     AND B.x=1 AND B.y IN (1);
} {10 10 10 1 1 1 |}
do_execsql_test in4-3.32 {
  EXPLAIN QUERY PLAN
  SELECT *, '|' FROM t3 A, t3 B
   WHERE A.x=10 AND A.y IN (10)
     AND B.x=1 AND B.y IN (1);
} {~/B-TREE/}  ;# No separate sorting pass
do_execsql_test in4-3.33 {
  SELECT *, '|' FROM t3 A, t3 B
   WHERE A.x IN (10) AND A.y=10
     AND B.x IN (1) AND B.y=1;
} {10 10 10 1 1 1 |}
do_execsql_test in4-3.34 {
  EXPLAIN QUERY PLAN
  SELECT *, '|' FROM t3 A, t3 B
   WHERE A.x IN (10) AND A.y=10
     AND B.x IN (1) AND B.y=1;
} {~/B-TREE/}  ;# No separate sorting pass

# An expression of the form "x IN (?,?)" creates an ephemeral table to
# hold the list of values on the RHS.  But "x IN (?)" does not create
# an ephemeral table.
#
do_execsql_test in4-3.41 {
  SELECT * FROM t3 WHERE x IN (10,11);
} {10 10 10}
do_execsql_test in4-3.42 {
  EXPLAIN
  SELECT * FROM t3 WHERE x IN (10,11);
} {/OpenEphemeral/}
do_execsql_test in4-3.43 {
  SELECT * FROM t3 WHERE x IN (10);
} {10 10 10}
do_execsql_test in4-3.44 {
  EXPLAIN
  SELECT * FROM t3 WHERE x IN (10);
} {~/OpenEphemeral/}
do_execsql_test in4-3.45 {
  SELECT * FROM t3 WHERE x NOT IN (10,11);
} {1 1 1}
do_execsql_test in4-3.46 {
  EXPLAIN
  SELECT * FROM t3 WHERE x NOT IN (10,11);
} {/OpenEphemeral/}
do_execsql_test in4-3.47 {
  SELECT * FROM t3 WHERE x NOT IN (10);
} {1 1 1}
do_execsql_test in4-3.48 {
  EXPLAIN
  SELECT * FROM t3 WHERE x NOT IN (10);
} {~/OpenEphemeral/}

# Make sure that when "x IN (?)" is converted into "x==?" that collating
# sequence and affinity computations do not get messed up.
#
do_execsql_test in4-4.1 {
  CREATE TABLE t4a(a TEXT, b TEXT COLLATE nocase, c);
  INSERT INTO t4a VALUES('ABC','abc',1);
  INSERT INTO t4a VALUES('def','xyz',2);
  INSERT INTO t4a VALUES('ghi','ghi',3);
  SELECT c FROM t4a WHERE a=b ORDER BY c;
} {3}
do_execsql_test in4-4.2 {
  SELECT c FROM t4a WHERE b=a ORDER BY c;
} {1 3}
do_execsql_test in4-4.3 {
  SELECT c FROM t4a WHERE (a||'')=b ORDER BY c;
} {1 3}
do_execsql_test in4-4.4 {
  SELECT c FROM t4a WHERE (a||'')=(b||'') ORDER BY c;
} {3}
do_execsql_test in4-4.5 {
  SELECT c FROM t4a WHERE a IN (b) ORDER BY c;
} {3}
do_execsql_test in4-4.6 {
  SELECT c FROM t4a WHERE (a||'') IN (b) ORDER BY c;
} {3}


do_execsql_test in4-4.11 {
  CREATE TABLE t4b(a TEXT, b NUMERIC, c);
  INSERT INTO t4b VALUES('1.0',1,4);
  SELECT c FROM t4b WHERE a=b;
} {4}
do_execsql_test in4-4.12 {
  SELECT c FROM t4b WHERE b=a;
} {4}
do_execsql_test in4-4.13 {
  SELECT c FROM t4b WHERE +a=b;
} {4}
do_execsql_test in4-4.14 {
  SELECT c FROM t4b WHERE a=+b;
} {}
do_execsql_test in4-4.15 {
  SELECT c FROM t4b WHERE +b=a;
} {}
do_execsql_test in4-4.16 {
  SELECT c FROM t4b WHERE b=+a;
} {4}
do_execsql_test in4-4.17 {
  SELECT c FROM t4b WHERE a IN (b);
} {}
do_execsql_test in4-4.18 {
  SELECT c FROM t4b WHERE b IN (a);
} {4}
do_execsql_test in4-4.19 {
  SELECT c FROM t4b WHERE +b IN (a);
} {}

do_execsql_test in4-5.1 {
  CREATE TABLE t5(c INTEGER PRIMARY KEY, d TEXT COLLATE nocase);
  INSERT INTO t5 VALUES(17, 'fuzz');
  SELECT 1 FROM t5 WHERE 'fuzz' IN (d);  -- match
  SELECT 2 FROM t5 WHERE 'FUZZ' IN (d);  -- no match
  SELECT 3 FROM t5 WHERE d IN ('fuzz');  -- match
  SELECT 4 FROM t5 WHERE d IN ('FUZZ');  -- match
} {1 3 4}

# An expression of the form "x IN (y)" can be used as "x=y" by the
# query planner when computing transitive constraints or to run the
# query using an index on y.
#
do_execsql_test in4-6.1 {
  CREATE TABLE t6a(a INTEGER PRIMARY KEY, b);
  INSERT INTO t6a VALUES(1,2),(3,4),(5,6);
  CREATE TABLE t6b(c INTEGER PRIMARY KEY, d);
  INSERT INTO t6b VALUES(4,44),(5,55),(6,66);

  SELECT * FROM t6a, t6b WHERE a=3 AND b IN (c);
} {3 4 4 44}
do_execsql_test in4-6.1-eqp {
  EXPLAIN QUERY PLAN
  SELECT * FROM t6a, t6b WHERE a=3 AND b IN (c);
} {~/SCAN/}
do_execsql_test in4-6.2 {
  SELECT * FROM t6a, t6b WHERE a=3 AND c IN (b);
} {3 4 4 44}
do_execsql_test in4-6.2-eqp {
  EXPLAIN QUERY PLAN
  SELECT * FROM t6a, t6b WHERE a=3 AND c IN (b);
} {~/SCAN/}


finish_test