First cut at adding the COLLATE operator. Regression tests pass (or at least

the quick set does) and a few new tests have been added.  But many more
tests are needed.  Rules for combining collations need to be worked out. (CVS 3624)

FossilOrigin-Name: 85cca7cd252d46ba71d302a89bc67c56146ec552

1 files changed, 22 insertions, 3 deletions

diff --git a/src/expr.c b/src/expr.c
index a20e1541c..7b34352c9 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -12,7 +12,7 @@
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 **
-** $Id: expr.c,v 1.272 2007/02/01 01:40:44 drh Exp $
+** $Id: expr.c,v 1.273 2007/02/01 23:02:45 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -50,6 +50,21 @@ char sqlite3ExprAffinity(Expr *pExpr){
 }
 
 /*
+** Set the collating sequence for expression pExpr to be the collating
+** sequence named by pToken.   Return a pointer to the revised expression.
+*/
+Expr *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pName){
+  CollSeq *pColl;
+  if( pExpr==0 ) return 0;
+  pColl = sqlite3LocateCollSeq(pParse, (char*)pName->z, pName->n);
+  if( pColl ){
+    pExpr->pColl = pColl;
+    pExpr->flags |= EP_ExpCollate;
+  }
+  return pExpr;
+}
+
+/*
 ** Return the default collation sequence for the expression pExpr. If
 ** there is no default collation type, return 0.
 */
@@ -890,7 +905,9 @@ static int lookupName(
             /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
             pExpr->iColumn = j==pTab->iPKey ? -1 : j;
             pExpr->affinity = pTab->aCol[j].affinity;
-            pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+            if( (pExpr->flags & EP_ExpCollate)==0 ){
+              pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+            }
             if( i<pSrcList->nSrc-1 ){
               if( pItem[1].jointype & JT_NATURAL ){
                 /* If this match occurred in the left table of a natural join,
@@ -946,7 +963,9 @@ static int lookupName(
             cnt++;
             pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol;
             pExpr->affinity = pTab->aCol[iCol].affinity;
-            pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+            if( (pExpr->flags & EP_ExpCollate)==0 ){
+              pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+            }
             pExpr->pTab = pTab;
             break;
           }