Using MySql User Defined Variables in .NET MySqlCommand

When executing a MySQL statement involving user defined variables within .NET MySqlCommand, you may encounter a fatal error. To resolve this issue, follow these steps:

In your code, you have a MySQL statement that sets a user defined variable, "@a", and then selects its value. However, you are encountering an error when attempting to execute this statement.

The error arises because MySQL user defined variables are not enabled by default in MySqlCommand. To enable them, append ";Allow User Variables=True" to the connection string:

$connectionstring = "Server=$Server;Port=$port;Database=$DataBase;Uid=$User;Pwd=$Password;allow zero datetime=yes;Allow User Variables=True"
$conn.ConnectionString = $connectionstring

This ensures that user defined variables are permitted within your connection. After making this adjustment, you should be able to successfully execute your query and retrieve the expected result.