Mybatis plus the lambda method can use SQL built-in functions (together), or like jpa, the aggregation function, for example,
Like this:
QueryWrapper 've=new QueryWrapper<> (a);
LambdaQueryWrapper Qwlambda='ve. Lambda ();
Qwlambda. Select (Employee: : getId);
//lambda how to use the SQL function

//similar:
//'ve. Select (" avg (id) as avg_ad ");