[virtual layer] Fix xFilter for null value comparisons

Hugo Mercier · Hugo Mercier · commit d6e0120a1ce0 · 2016-12-05T10:18:15.000+01:00
diff --git a/src/providers/virtual/qgsvirtuallayersqlitemodule.cpp b/src/providers/virtual/qgsvirtuallayersqlitemodule.cpp
@@ -616,13 +616,13 @@ int vtableFilter( sqlite3_vtab_cursor * cursor, int idxNum, const char *idxStr,
         expr += "'" + str.replace( "'", "''" ) + "'";
         break;
       }
+      case SQLITE_NULL:
+      case SQLITE_BLOB: // comparison to blob ignored
       default:
-        expr = "";
-    }
-    if ( !expr.isEmpty() )
-    {
-      request.setFilterExpression( expr );
+        expr += " is null";
+        break;
     }
+    request.setFilterExpression( expr );
   }
   VTableCursor *c = reinterpret_cast<VTableCursor*>( cursor );
   c->filter( request );

Original file line number	Diff line number	Diff line change
`@@ -616,13 +616,13 @@ int vtableFilter( sqlite3_vtab_cursor * cursor, int idxNum, const char *idxStr,`
`616`	`616`	`expr += "'" + str.replace( "'", "''" ) + "'";`
`617`	`617`	`break;`
`618`	`618`	`}`
	`619`	`+ case SQLITE_NULL:`
	`620`	`+ case SQLITE_BLOB: // comparison to blob ignored`
`619`	`621`	`default:`
`620`		`- expr = "";`
`621`		`- }`
`622`		`- if ( !expr.isEmpty() )`
`623`		`- {`
`624`		`- request.setFilterExpression( expr );`
	`622`	`+ expr += " is null";`
	`623`	`+ break;`
`625`	`624`	`}`
	`625`	`+ request.setFilterExpression( expr );`
`626`	`626`	`}`
`627`	`627`	`VTableCursor c = reinterpret_cast<VTableCursor>( cursor );`
`628`	`628`	`c->filter( request );`