Fix a bug in the LIKE optimizer that occurs when the last character

before the wildcard is an upper-case 'Z'.  Ticket #2959. (CVS 4807)

FossilOrigin-Name: 610574b23b5e73b71be71df66e084c5bf37f6ccd

diff --git a/manifest b/manifest
index 8e44d274af8b45689f8203001db31472ce08e457..fc1d79550a042ef037caecfc61623577661ff9e9 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Additional\stest\scases.\s(CVS\s4806)
-D 2008-02-21T21:30:07
+C Fix\sa\sbug\sin\sthe\sLIKE\soptimizer\sthat\soccurs\swhen\sthe\slast\scharacter\nbefore\sthe\swildcard\sis\san\supper-case\s'Z'.\s\sTicket\s#2959.\s(CVS\s4807)
+D 2008-02-23T21:55:40
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in bc2b5df3e3d0d4b801b824b7ef6dec43812b049b
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -181,7 +181,7 @@ F src/vdbeblob.c 63c750acc7b5012479f508c0e9627372a82cb65d
 F src/vdbefifo.c a30c237b2a3577e1415fb6e288cbb6b8ed1e5736
 F src/vdbemem.c 2d87d65430519dfb2103498b76bf15e4038b12b0
 F src/vtab.c dc8947c9c79780b19ee6d6bae4ea624a2a303353
-F src/where.c 7ff0ca021cc77086e367ed3b6308fbc6bc9e1a31
+F src/where.c f899a98f9823b965730d94b1c7c425f9ba914c12
 F tclinstaller.tcl 4356d9d94d2b5ed5e68f9f0c80c4df3048dd7617
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/all.test d12210212bada2bde6d5aeb90969b86c1aa977d2
@@ -361,7 +361,7 @@ F test/join5.test 86675fc2919269aa923c84dd00ee4249b97990fe
 F test/journal1.test 36f2d1bb9bf03f790f43fbdb439e44c0657fab19
 F test/lastinsert.test 474d519c68cb79d07ecae56a763aa7f322c72f51
 F test/laststmtchanges.test 18ead86c8a87ade949a1d5658f6dc4bb111d1b02
-F test/like.test d2d5efc471db314f662a6f0cfa52c6ec2d4fed8b
+F test/like.test 2a3ddbd5d91503f914eabae67a47c4196fe33a58
 F test/limit.test ca61a9fc520f54470edb3a771167fe4b68abc247
 F test/loadext.test 1911e7365a6d31d77ba00dd3a8a31b7f2111a670
 F test/loadext2.test 95ca7e2cb03fd3e068de97c3a2fe58dbdfd769e1
@@ -621,7 +621,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 4c9a7b42b797f42f2b1e2e8d6a260044bd22ef2d
-R 15fbbd63bac94bf4cf3996d2a4103198
+P 74126bf4e605dc875adbf5a0ee83bf8112891e35
+R 61ff14acc658996aa4f2c96b0d9cdcfb
 U drh
-Z 3ade4f046651b84bc599a69e7912090d
+Z bc51f98ef19af3970b42d08ccd4bf327

diff --git a/manifest.uuid b/manifest.uuid
index 4ae7915526d97d1343c01ed9dd28621cc397a214..5ec44852f84727e42acfbca5ac6b9c4d29094b4d 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-74126bf4e605dc875adbf5a0ee83bf8112891e35
\ No newline at end of file
+610574b23b5e73b71be71df66e084c5bf37f6ccd
\ No newline at end of file

diff --git a/src/where.c b/src/where.c
index 50bcea2ddbf9213a0da354657ee4170d6acc2523..0c222204c5dec66994209e407a4ae6838d76bf1b 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -16,7 +16,7 @@
 ** so is applicable.  Because this module is responsible for selecting
 ** indices, you might also think of this module as the "query optimizer".
 **
-** $Id: where.c,v 1.286 2008/01/23 12:52:41 drh Exp $
+** $Id: where.c,v 1.287 2008/02/23 21:55:40 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -517,19 +517,22 @@ static int isLikeOrGlob(
   sqlite3 *db,      /* The database */
   Expr *pExpr,      /* Test this expression */
   int *pnPattern,   /* Number of non-wildcard prefix characters */
-  int *pisComplete  /* True if the only wildcard is % in the last character */
+  int *pisComplete, /* True if the only wildcard is % in the last character */
+  int *pnoCase      /* True if uppercase is equivalent to lowercase */
 ){
   const char *z;
   Expr *pRight, *pLeft;
   ExprList *pList;
   int c, cnt;
-  int noCase;
   char wc[3];
   CollSeq *pColl;
 
-  if( !sqlite3IsLikeFunction(db, pExpr, &noCase, wc) ){
+  if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
     return 0;
   }
+#ifdef SQLITE_EBCDIC
+  if( *pnoCase ) return 0;
+#endif
   pList = pExpr->pList;
   pRight = pList->a[0].pExpr;
   if( pRight->op!=TK_STRING ){
@@ -545,8 +548,8 @@ static int isLikeOrGlob(
     /* No collation is defined for the ROWID.  Use the default. */
     pColl = db->pDfltColl;
   }
-  if( (pColl->type!=SQLITE_COLL_BINARY || noCase) &&
-      (pColl->type!=SQLITE_COLL_NOCASE || !noCase) ){
+  if( (pColl->type!=SQLITE_COLL_BINARY || *pnoCase) &&
+      (pColl->type!=SQLITE_COLL_NOCASE || !*pnoCase) ){
     return 0;
   }
   sqlite3DequoteExpr(db, pRight);
@@ -716,6 +719,7 @@ static void exprAnalyze(
   Bitmask prereqAll;
   int nPattern;
   int isComplete;
+  int noCase;
   int op;
   Parse *pParse = pWC->pParse;
   sqlite3 *db = pParse->db;
@@ -886,8 +890,16 @@ or_not_possible:
 #ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
   /* Add constraints to reduce the search space on a LIKE or GLOB
   ** operator.
+  **
+  ** A like pattern of the form "x LIKE 'abc%'" is changed into constraints
+  **
+  **          x>='abc' AND x<'abd' AND x LIKE 'abc%'
+  **
+  ** The last character of the prefix "abc" is incremented to form the
+  ** termination condidtion "abd".  This trick of incrementing the last
+  ** is not 255 and if the character set is not EBCDIC.  
   */
-  if( isLikeOrGlob(db, pExpr, &nPattern, &isComplete) ){
+  if( isLikeOrGlob(db, pExpr, &nPattern, &isComplete, &noCase) ){
     Expr *pLeft, *pRight;
     Expr *pStr1, *pStr2;
     Expr *pNewExpr1, *pNewExpr2;
@@ -903,8 +915,12 @@ or_not_possible:
     }
     pStr2 = sqlite3ExprDup(db, pStr1);
     if( !db->mallocFailed ){
+      u8 c, *pC;
       assert( pStr2->token.dyn );
-      ++*(u8*)&pStr2->token.z[nPattern-1];
+      pC = (u8*)&pStr2->token.z[nPattern-1];
+      c = *pC;
+      if( noCase ) c = sqlite3UpperToLower[c];
+      *pC = c + 1;
     }
     pNewExpr1 = sqlite3PExpr(pParse, TK_GE, sqlite3ExprDup(db,pLeft), pStr1, 0);
     idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);

diff --git a/test/like.test b/test/like.test
index 236529858e892739c4083e21726017d2ff90f47e..57f1086d91c406a81d46e30963f1b95b76d36bf0 100644 (file)
--- a/test/like.test
+++ b/test/like.test
@@ -13,7 +13,7 @@
 # in particular the optimizations that occur to help those operators
 # run faster.
 #
-# $Id: like.test,v 1.8 2008/01/23 12:52:41 drh Exp $
+# $Id: like.test,v 1.9 2008/02/23 21:55:40 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -381,6 +381,114 @@ do_test like-5.7 {
 do_test like-5.8 {
   set sqlite_like_count
 } 12
+do_test like-5.11 {
+  execsql {PRAGMA case_sensitive_like=off}
+  set sqlite_like_count 0
+  queryplan {
+    SELECT x FROM t1 WHERE x LIKE 'ABC%' ORDER BY 1
+  }
+} {ABC {ABC abc xyz} abc abcd nosort {} i1}
+do_test like-5.12 {
+  set sqlite_like_count
+} 12
+do_test like-5.13 {
+  set sqlite_like_count 0
+  queryplan {
+    SELECT x FROM t2 WHERE x LIKE 'ABC%' ORDER BY 1
+  }
+} {abc ABC {ABC abc xyz} abcd nosort {} i2}
+do_test like-5.14 {
+  set sqlite_like_count
+} 0
+do_test like-5.15 {
+  execsql {
+    PRAGMA case_sensitive_like=on;
+  }
+  set sqlite_like_count 0
+  queryplan {
+    SELECT x FROM t2 WHERE x LIKE 'ABC%' ORDER BY 1
+  }
+} {ABC {ABC abc xyz} nosort {} i2}
+do_test like-5.16 {
+  set sqlite_like_count
+} 12
+do_test like-5.17 {
+  execsql {
+    PRAGMA case_sensitive_like=off;
+  }
+  set sqlite_like_count 0
+  queryplan {
+    SELECT x FROM t2 WHERE x GLOB 'ABC*' ORDER BY 1
+  }
+} {ABC {ABC abc xyz} nosort {} i2}
+do_test like-5.18 {
+  set sqlite_like_count
+} 12
+
+# Boundary case.  The prefix for a LIKE comparison is rounded up
+# when constructing the comparison.  Example:  "ab" becomes "ac".
+# In other words, the last character is increased by one.
+#
+# Make sure this happens correctly when the last character is a 
+# "z" and we are doing case-insensitive comparisons.
+#
+# Ticket #2959
+#
+do_test like-5.21 {
+  execsql {
+    PRAGMA case_sensitive_like=off;
+    INSERT INTO t2 VALUES('ZZ-upper-upper');
+    INSERT INTO t2 VALUES('zZ-lower-upper');
+    INSERT INTO t2 VALUES('Zz-upper-lower');
+    INSERT INTO t2 VALUES('zz-lower-lower');
+  }
+  queryplan {
+    SELECT x FROM t2 WHERE x LIKE 'zz%';
+  }
+} {zz-lower-lower zZ-lower-upper Zz-upper-lower ZZ-upper-upper nosort {} i2}
+do_test like-5.22 {
+  queryplan {
+    SELECT x FROM t2 WHERE x LIKE 'zZ%';
+  }
+} {zz-lower-lower zZ-lower-upper Zz-upper-lower ZZ-upper-upper nosort {} i2}
+do_test like-5.23 {
+  queryplan {
+    SELECT x FROM t2 WHERE x LIKE 'Zz%';
+  }
+} {zz-lower-lower zZ-lower-upper Zz-upper-lower ZZ-upper-upper nosort {} i2}
+do_test like-5.24 {
+  queryplan {
+    SELECT x FROM t2 WHERE x LIKE 'ZZ%';
+  }
+} {zz-lower-lower zZ-lower-upper Zz-upper-lower ZZ-upper-upper nosort {} i2}
+do_test like-5.25 {
+  queryplan {
+    PRAGMA case_sensitive_like=on;
+    CREATE TABLE t3(x);
+    CREATE INDEX i3 ON t3(x);
+    INSERT INTO t3 VALUES('ZZ-upper-upper');
+    INSERT INTO t3 VALUES('zZ-lower-upper');
+    INSERT INTO t3 VALUES('Zz-upper-lower');
+    INSERT INTO t3 VALUES('zz-lower-lower');
+    SELECT x FROM t3 WHERE x LIKE 'zz%';
+  }
+} {zz-lower-lower nosort {} i3}
+do_test like-5.26 {
+  queryplan {
+    SELECT x FROM t3 WHERE x LIKE 'zZ%';
+  }
+} {zZ-lower-upper nosort {} i3}
+do_test like-5.27 {
+  queryplan {
+    SELECT x FROM t3 WHERE x LIKE 'Zz%';
+  }
+} {Zz-upper-lower nosort {} i3}
+do_test like-5.28 {
+  queryplan {
+    SELECT x FROM t3 WHERE x LIKE 'ZZ%';
+  }
+} {ZZ-upper-upper nosort {} i3}
+
 
 # ticket #2407
 #