select 指定 列值

two way:

roleid列并不在表sys_user中，虚拟roleid列，指定roleid列的值均为aaa，以下两种方式实现。

1.username 为表sys_user中存在的列。

select userid,replace(username,username,'aaa') as roleid from sys_user ;

2.

select userid,'aaa' roleid from sys_user;

purpose

insert into sys_user_role (userid,roleid) select userid,'aaa' roleid from sys_user;

insert into sys_user_role (userid,roleid) select userid,replace(username,username,'aaa') as roleid from sys_user ;