c# - .NET MySqlCommand @ 占位符与 MySQL 变量冲突

Question

这是针对此问题的示例 SQL。 (实际的SQL比这个复杂多了)

SET @HELLO = 1;
SELECT @HELLO;

如您所见。 @HELLO 是一个 MySQL 变量，但 .NET MySQLCommand 将其视为占位符而不需要绑定(bind)值。无论如何，我可以在 .NET 中使用 MySQL 变量吗？

Answer 1

看看下面的MySql.Data.MySqlClient.MySqlException: Parameter ‘@id’ must be defined

哪个州

Finally, I found that this was indeed a change in the .Net Connector. (I’m not sure what version number but starting from 5.2.0 would be my guess) Starting from version 5.2.2 of the Connector you should add the Allow User Variables=True Connection String Setting in order to use User Defined Variables in your SQL statements.

Example of Connection String:

 Database=testdb;Data Source=localhost;User Id=root;Password=hello;Allow User Variables=True