Add experimental support for LIKE, GLOB and REGEXP to the virtual table interface.

FossilOrigin-Name: 277a5b4027d4c2caba8143228a4f7d6df899dbb4

src/sqlite.h.in

@@ -5709,12 +5709,15 @@ struct sqlite3_index_info {
 ** an operator that is part of a constraint term in the wHERE clause of
 ** a query that uses a [virtual table].
 */
-#define SQLITE_INDEX_CONSTRAINT_EQ    2
-#define SQLITE_INDEX_CONSTRAINT_GT    4
-#define SQLITE_INDEX_CONSTRAINT_LE    8
-#define SQLITE_INDEX_CONSTRAINT_LT    16
-#define SQLITE_INDEX_CONSTRAINT_GE    32
-#define SQLITE_INDEX_CONSTRAINT_MATCH 64
+#define SQLITE_INDEX_CONSTRAINT_EQ      2
+#define SQLITE_INDEX_CONSTRAINT_GT      4
+#define SQLITE_INDEX_CONSTRAINT_LE      8
+#define SQLITE_INDEX_CONSTRAINT_LT     16
+#define SQLITE_INDEX_CONSTRAINT_GE     32
+#define SQLITE_INDEX_CONSTRAINT_MATCH  64
+#define SQLITE_INDEX_CONSTRAINT_LIKE   65
+#define SQLITE_INDEX_CONSTRAINT_GLOB   66
+#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
 
 /*
 ** CAPI3REF: Register A Virtual Table Implementation

src/test8.c

@@ -849,6 +849,12 @@ static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
           zOp = ">="; break;
         case SQLITE_INDEX_CONSTRAINT_MATCH:
           zOp = "LIKE"; break;
+        case SQLITE_INDEX_CONSTRAINT_LIKE:
+          zOp = "like"; break;
+        case SQLITE_INDEX_CONSTRAINT_GLOB:
+          zOp = "glob"; break;
+        case SQLITE_INDEX_CONSTRAINT_REGEXP:
+          zOp = "regexp"; break;
       }
       if( zOp[0]=='L' ){
         zNew = sqlite3_mprintf(" %s %s LIKE (SELECT '%%'||?||'%%')", 

src/where.c

@@ -893,6 +893,9 @@ static sqlite3_index_info *allocateIndexInfo(
     pIdxCons[j].iTermOffset = i;
     op = (u8)pTerm->eOperator & WO_ALL;
     if( op==WO_IN ) op = WO_EQ;
+    if( op==WO_MATCH ){
+      op = pTerm->eMatchOp;
+    }
     pIdxCons[j].op = op;
     /* The direct assignment in the previous line is possible only because
     ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The

src/whereInt.h

@@ -253,6 +253,7 @@ struct WhereTerm {
   u16 eOperator;          /* A WO_xx value describing <op> */
   u16 wtFlags;            /* TERM_xxx bit flags.  See below */
   u8 nChild;              /* Number of children that must disable us */
+  u8 eMatchOp;            /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
   WhereClause *pWC;       /* The clause this term is part of */
   Bitmask prereqRight;    /* Bitmask of tables used by pExpr->pRight */
   Bitmask prereqAll;      /* Bitmask of tables referenced by pExpr */

src/whereexpr.c

@@ -282,16 +282,24 @@ static int isLikeOrGlob(
 ** If it is then return TRUE.  If not, return FALSE.
 */
 static int isMatchOfColumn(
-  Expr *pExpr      /* Test this expression */
+  Expr *pExpr,                    /* Test this expression */
+  unsigned char *peOp2            /* OUT: 0 for MATCH, or else an op2 value */
 ){
+  struct Op2 {
+    const char *zOp;
+    unsigned char eOp2;
+  } aOp[] = {
+    { "match", SQLITE_INDEX_CONSTRAINT_MATCH },
+    { "glob",  SQLITE_INDEX_CONSTRAINT_GLOB },
+    { "like",  SQLITE_INDEX_CONSTRAINT_LIKE },
+    { "regex", SQLITE_INDEX_CONSTRAINT_REGEXP }
+  };
   ExprList *pList;
+  int i;
 
   if( pExpr->op!=TK_FUNCTION ){
     return 0;
   }
-  if( sqlite3StrICmp(pExpr->u.zToken,"match")!=0 ){
-    return 0;
-  }
   pList = pExpr->x.pList;
   if( pList->nExpr!=2 ){
     return 0;
@@ -299,7 +307,13 @@ static int isMatchOfColumn(
   if( pList->a[1].pExpr->op != TK_COLUMN ){
     return 0;
   }
-  return 1;
+  for(i=0; i<ArraySize(aOp); i++){
+    if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
+      *peOp2 = aOp[i].eOp2;
+      return 1;
+    }
+  }
+  return 0;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
@@ -876,6 +890,7 @@ static void exprAnalyze(
   int op;                          /* Top-level operator.  pExpr->op */
   Parse *pParse = pWInfo->pParse;  /* Parsing context */
   sqlite3 *db = pParse->db;        /* Database connection */
+  unsigned char eOp2;              /* op2 value for LIKE/REGEXP/GLOB */
 
   if( db->mallocFailed ){
     return;
@@ -1099,7 +1114,7 @@ static void exprAnalyze(
   ** virtual tables.  The native query optimizer does not attempt
   ** to do anything with MATCH functions.
   */
-  if( isMatchOfColumn(pExpr) ){
+  if( isMatchOfColumn(pExpr, &eOp2) ){
     int idxNew;
     Expr *pRight, *pLeft;
     WhereTerm *pNewTerm;
@@ -1120,6 +1135,7 @@ static void exprAnalyze(
       pNewTerm->leftCursor = pLeft->iTable;
       pNewTerm->u.leftColumn = pLeft->iColumn;
       pNewTerm->eOperator = WO_MATCH;
+      pNewTerm->eMatchOp = eOp2;
       markTermAsChild(pWC, idxNew, idxTerm);
       pTerm = &pWC->a[idxTerm];
       pTerm->wtFlags |= TERM_COPIED;