SQLite

    if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
    if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
    if( pA->op!=TK_STRING
     && pA->op!=TK_TRUEFALSE
     && (combinedFlags & EP_Reduced)==0
    ){
      if( pA->iColumn!=pB->iColumn ) return 2;
      if( pA->op2!=pB->op2 ) return 2;
      if( pA->iTable!=pB->iTable 
       && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
    }
  }
  return 0;
}

                         ** EP_Unlikely:  134217728 times likelihood
                         ** TK_SELECT: 1st register of result vector */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1).
                         ** TK_SELECT_COLUMN: column of the result vector */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 op2;                /* TK_REGISTER/TK_TRUTH: original value of Expr.op
                         ** TK_COLUMN: the value of p5 for OP_Column
                         ** TK_AGG_FUNCTION: nesting depth */
  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  union {
    Table *pTab;           /* TK_COLUMN: Table containing column. Can be NULL
                           ** for a column of an index on an expression */
    Window *pWin;          /* TK_FUNCTION: Window definition for the func */

# 2019 May 20
#
# 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.  The
# focus of this file is testing expressions.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix expr2

do_execsql_test 1.0 {
  CREATE TABLE t0(c0);
  INSERT INTO t0(c0) VALUES ('val');
}

do_execsql_test 1.1 {
  SELECT * FROM t0 WHERE (
      ( (0 IS NOT FALSE) OR NOT (0 IS FALSE OR (t0.c0 = 1)) ) IS 0
  )
} {val}

do_execsql_test 1.2.1 {
  SELECT 
      ( (0 IS NOT FALSE) OR NOT (0 IS FALSE OR (t0.c0 = 1)) ) IS 0
  FROM t0 
} {1}

do_execsql_test 1.2.2 {
  SELECT 
      ( (0 IS NOT FALSE) OR NOT (0 IS 0 OR (t0.c0 = 1)) ) IS 0
  FROM t0 
} {1}

do_execsql_test 1.3 {
  SELECT ( (0 IS NOT FALSE) OR NOT (0 IS FALSE OR (t0.c0 = 1)) ) FROM t0 
} {0}

do_execsql_test 1.4.1 {
  SELECT (0 IS NOT FALSE) FROM t0 
} {0}
do_execsql_test 1.4.2 {
  SELECT NOT (0 IS FALSE OR (t0.c0 = 1)) FROM t0 
} {0}


finish_test

do_eqp_test index7-6.4 {
  SELECT * FROM v4 WHERE d='xyz' AND c='def'
} {SEARCH TABLE t4 USING INDEX i4 (c=?)}

do_catchsql_test index7-6.5 {
  CREATE INDEX t5a ON t5(a) WHERE a=#1;
} {1 {near "#1": syntax error}}

do_execsql_test index7-7.0 {
  CREATE TABLE t6(x, y);
  INSERT INTO t6 VALUES(1, 1);
  INSERT INTO t6 VALUES(0, 0);
  SELECT * FROM t6 WHERE y IS TRUE ORDER BY x;
} {1 1}

do_execsql_test index7-7.1 {
  CREATE INDEX i6 ON t6(x) WHERE y IS NOT TRUE;
  SELECT * FROM t6 WHERE y IS TRUE ORDER BY x;
} {1 1}


finish_test