Question

In my c# application i am trying to delete a record and i am returning result of the executenonquery to check the deletion is exactly happening as below.

rowsAffected = db.ExecuteNonQuerySQL(
    @"DELETE FROM relation WHERE parent_itemid = " + SourceThingId + " AND " +
    "     child_itemid = " + ThingId + " AND " +
    "     relation_typeid = " + RelationTypeId);

And the executenonquery is definesd as below,

using (SQLiteTransaction dbtrans = conn.BeginTransaction())
{
    SQLiteCommand cmd = conn.CreateCommand();
    cmd.CommandText = sqlExpr;
    cmd.CommandType = CommandType.Text;
    ireturn = cmd.ExecuteNonQuery();
    dbtrans.Commit();
}
return ireturn;

But when i am executing its not deleting and the value returns 0.The databse used is sqlite.

Do any one have idea why it happens.Please help.

Thanx in advance.

Answer 1

Well it certainly sounds like the record simply isn’t there. You should debug this by running a SELECT * with the same query, and see whether you get any results back.

You should also stop putting your values directly into SQL, and instead use parameterized SQL. That will give a better separation of code and data, avoid SQL injection attacks, and avoid conversion issues (particularly with date/time values).