[virtual layer] Fix xFilter for null value comparisons

Hugo Mercier · Hugo Mercier · commit 95ae154889fe · 2016-12-05T11:01:18.000+01:00
diff --git a/src/providers/virtual/qgsvirtuallayersqlitemodule.cpp b/src/providers/virtual/qgsvirtuallayersqlitemodule.cpp
@@ -619,13 +619,13 @@ 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
`@@ -619,13 +619,13 @@ int vtableFilter( sqlite3_vtab_cursor * cursor, int idxNum, const char *idxStr,`
`619`	`619`	`expr += "'" + str.replace( "'", "''" ) + "'";`
`620`	`620`	`break;`
`621`	`621`	`}`
	`622`	`+ case SQLITE_NULL:`
	`623`	`+ case SQLITE_BLOB: // comparison to blob ignored`
`622`	`624`	`default:`
`623`		`- expr = "";`
`624`		`- }`
`625`		`- if ( !expr.isEmpty() )`
`626`		`- {`
`627`		`- request.setFilterExpression( expr );`
	`625`	`+ expr += " is null";`
	`626`	`+ break;`
`628`	`627`	`}`
	`628`	`+ request.setFilterExpression( expr );`
`629`	`629`	`}`
`630`	`630`	`VTableCursor c = reinterpret_cast<VTableCursor>( cursor );`
`631`	`631`	`c->filter( request );`