“TableDetails”中列“IsPrimaryKey”的值为DBNull. Mysql EntityFramework

Entity Framework连接MySQL时：由于出现以下异常,无法生成模型:“表“TableDetails”中列“IsPrimaryKey”的值为DBNull.

解决方案：

Execute the following commands in MySQL.
   use <<database name>>;
   set global optimizer_switch='derived_merge=OFF';

 http://stackoverflow.com/questions/33575109/mysql-entity-the-value-for-column-isprimarykey-in-table-tabledetails-is