SQLite: Check-in [e43da426]

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Overview

Comment:	Make sure the query optimizer for aggregate queries knows that expressions (x='a') and (x='A') are different. Ticket [fa7bf5ec94801e7e]
Downloads:	Tarball \| ZIP archive \| SQL archive
Timelines:	family \| ancestors \| descendants \| both \| trunk
Files:	files \| file ages \| folders
SHA1:	e43da426e66e6b63d5ed9610a6308aba0089313b
User & Date:	drh 2011-10-13 15:35:52

Context

2011-10-13
16:02		Enable large-file support for fopen() and friends in the command-line shell. Ticket [92af7da36b6fbd] check-in: eeeba4f0 user: drh tags: trunk
15:35		Make sure the query optimizer for aggregate queries knows that expressions (x='a') and (x='A') are different. Ticket [fa7bf5ec94801e7e] check-in: e43da426 user: drh tags: trunk
14:41		Make sure the page_count and quick_check pragmas work properly even when their names are capitalized. Fixes a problem reported on the mailing list. check-in: 150592b4 user: drh tags: trunk

Changes

Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/expr.c.

  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
  if( ExprHasProperty(pA, EP_IntValue) ){
    if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
      return 2;
    }
  }else if( pA->op!=TK_COLUMN && pA->u.zToken ){
    if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
    if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return 2;
    }
  }
  if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1;
  if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2;
  return 0;
}

  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
  if( ExprHasProperty(pA, EP_IntValue) ){
    if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
      return 2;
    }
  }else if( pA->op!=TK_COLUMN && pA->u.zToken ){
    if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
    if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return 2;
    }
  }
  if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1;
  if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2;
  return 0;
}

Added test/tkt-fa7bf5ec.test.

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# 2011 October 13
#
# 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 [fa7bf5ec94801e7e2030e41eefe5d9dd96eaacfd] has
# been resolved.
#
# The problem described by this ticket was that the sqlite3ExprCompare()
# function was saying that expressions (x='a') and (x='A') were identical
# because it was using sqlite3StrICmp() instead of strcmp() to compare string
# literals.  That was causing the query optimizer for aggregate queries to 
# believe that both count() operations were identical, and thus only 
# computing the first count() and making a copy of the result for the 
# second count().
#

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

do_test tkt-fa7bf5ec-1 {
  execsql {
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES ('a');
    INSERT INTO t1 VALUES ('A');
    INSERT INTO t1 VALUES ('A');
    SELECT count(CASE WHEN x='a' THEN 1 END),
           count(CASE WHEN x='A' THEN 1 END)
      FROM t1;
  }
} {1 2}

finish_test