NULL cannot be compared with the = operator; it is not equal with any value, even itself.
NULL
=
To compare with NULL, you have to use the IS NULL operator:
IS NULL
stmt = @"select * from test where shipToCode is null";
Try the following and check if there are any changes:
NSString *query = @"SELECT * FROM test WHERE shipToCode is NULL";FMResultSet *rs = [db executeQuery:query];int count = 0;while ([rs next]) { count++;}NSLog(@"Count %d", count);