查询高于20号部门最低工资的员工的编号和姓名及工资。

要查询高于20号部门最低工资的员工信息，首先需要确定每个部门的最低工资。假设有一个`departments`表用于存储部门信息，包括`department_id`和`min_salary`（部门最低工资），以及`employees`表存储员工信息，包括`employee_id`, `name`, 和 `salary`，同时有一个`department_employee`表连接了这两个表。查询可以这样编写：

WITH department_wages AS (
  SELECT d.department_id, MIN(e.salary) as min_salary_per_dept
  FROM departments d
  JOIN department_employee de ON d.department_id = de.department_id
  GROUP BY d.department_id
)

SELECT e.employee_id, e.name, e.salary
FROM employees e
JOIN department_employee de ON e.employee_id = de.employee_id
JOIN department_wages dw ON e.salary > dw.min_salary_per_dept AND de.department_id = dw.department_id
WHERE dw.department_id = 20;

这个查询先通过子查询`department_wages`找出每个部门的最低工资，然后在主查询中筛选出20号部门并且工资高于该最低工资的所有员工。