Where后跟查询条件来进行条件查询,其逻辑运算符用and,or,not表示,同时需要注意运算符的优先次序及括弧的使用。
示例:
1 查询教师表中所有工资低于6000或者工资大于8000的03系老师信息
SELECT
*
FROM
teacher
WHERE
(
teacher_salary < 6000
OR teacher_salary > 8000
)
AND dept_id = '03';
运行结果:
2 查询教师表中所有工资低于6000或者工资大于8000的03系老师姓名
SELECT
teacher_name
FROM
teacher
WHERE
(
teacher_salary < 6000
OR teacher_salary > 8000
)
AND dept_id = '03';
运行结果: