### Error querying database.  Cause: java.sql.SQLException: Operand should contain 1 column(s)

既然是sql報錯，應該是sql語句寫錯了，然後我看了下語句發現少寫了連線函式。

原句是這樣的

select  * from t_user where user_name like concat('%',#{username},'%') and password like ('%',#{password},'%')

改為

select  * from t_user where user_name like concat('%',#{username},'%') and password like concat('%',#{password},'%')