假设有两张表:departments (部门表)和 employees (员工表),它们之间有一个外键关系 department_id

部门表结构:

CREATE TABLE departments (
  department_id INT PRIMARY KEY,
  department_name VARCHAR(50)
);

员工表结构:

CREATE TABLE employees (
  employee_id INT PRIMARY KEY,
  employee_name VARCHAR(50),
  department_id INT,
  FOREIGN KEY (department_id) REFERENCES departments(department_id)
);

要列出部门名称和这些部门的员工信息,可以使用以下 SQL 查询:

SELECT d.department_name, e.employee_id, e.employee_name
FROM departments d
LEFT JOIN employees e ON d.department_id = e.department_id;

要列出没有员工的部门,可以使用以下 SQL 查询:

SELECT d.department_name
FROM departments d
LEFT JOIN employees e ON d.department_id = e.department_id
WHERE e.employee_id IS NULL;
``
列出部门名称和这些部门的员工信息同时列出那些没有员工的部门用SQL语句写出

原文地址: http://www.cveoy.top/t/topic/hAbG 著作权归作者所有。请勿转载和采集!

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