mysql-Parameter “@xx” must be defined

select n x, s y,@num from (select @num:=1 n,@str:='abc' s) as t

mysql支持使用@xxx变量名在select语句中定义变量和赋值，使用odbc方式查询sql时报错，“mysql-Parameter “@xx” must be defined”

通过连接字符串 加入 : Allow User Variables=True;解决

 

<add name="ConnectionString" connectionString="Database=test;Data Source=localhost;User Id=root;Password=root;charset=utf8;pooling=true;Allow User Variables=True"/>