Where後跟查詢條件來進行條件查詢,其邏輯運算符用and,or,not表示,同時需要注意運算符的優先次序及括弧的使用。
示例:
1 查詢教師表中所有工資低於6000或者工資大於8000的03系老師信息
SELECT
*
FROM
teacher
WHERE
(
teacher_salary < 6000
OR teacher_salary > 8000
)
AND dept_id = '03';
運行結果:
2 查詢教師表中所有工資低於6000或者工資大於8000的03系老師姓名
SELECT
teacher_name
FROM
teacher
WHERE
(
teacher_salary < 6000
OR teacher_salary > 8000
)
AND dept_id = '03';
運行結果: