Parameter '@myLeft' must be defined

Question

My question is quite similar to already answered ones but yet not. I\'d like some help sorting this out.

I\'m trying to add data to a database table but I get keepin

Answer 1

I found the solution to this problem by making an extensive Google search for undefined parameters in MySQL. This article (MySql.Data.MySqlClient.MySqlException: Parameter ‘@id’ must be defined) covers the basics of the problem. It's as far as I understand related to an upgrade of the connector.

You need to add Allow User Variables=True in the connection string in order to use custom variables. Pretty simple solution to an equally tough problem. ;)

Answer 2

The error is very much informative, you are just using @myLeft parameter in your query without defining it. you ned to define that parameter like the others you have done.

objCmdInsert.Parameters.Add("?myLeft",...

Answer 3

Can you try:

objCmdInsert.Parameters.Add("@myLeft", MySqlDbType.Int).Value = 1212;

You probably have to do it for EACH occurrence of that parameter.

It's not clear to me what's the meaning of SET @myLeft := lft; (You are trying to assign column value to parameter)

Answer 4

Before using @myLeft, you need to declare it. For example, assuming @myLeft is an INT:

DECLARE @myLeft INT;