MySql EF事务using不会自动 Rollback的bug

EF to MySql一般都是用using最后Commit,一直以为最后没Commit,当using调用Dispose会自动Rollback,没想到这儿有个坑,mysql有个bug并不会Rollback,事务也不会关闭,所以再次BeginTransaction就会报An error occurred while starting a transaction on the provider connection. See the inner exception for details.错误详情是Nested transactions are not supported.

所以用 EF to MySql一定要记得try catch Rollback

例子如下

using (var db = new OtoRCEntities())
{
    using (var tran = db.Database.BeginTransaction())
    {
        try
        {
            db.Database.ExecuteSqlCommand("update xxx");
            tran.Commit();
        }
        catch (Exception)//这儿try catch 是用来报错了没有Commit,按理说using后应该自动Rollback
        {
             
        }
 
    }
}
using (var db = new OtoRCEntities())
{
    using (var tran = db.Database.BeginTransaction())//到这儿就会报错
    {
        try
        {
            db.Database.ExecuteSqlCommand("update xxx");
            tran.Commit();
        }
        catch (Exception)
        {
 
        }
 
    }
}