案例

案例解析

查询年龄 20,21,22,23 岁的女员工信息

SELECT * FROM emp WHERE gender='女' and  age IN (20,21,22,23);

查询性别为男,并且年龄在 20-40 岁(含)以内的姓名为三个字的员工

SELECT *  from emp WHERE gender='男' and (age BETWEEN 20 AND 40) AND name LIKE '___';

统计员工表中 年龄小于 60 岁的,男员工和女员工的数量

SELECT gender,COUNT(*) FROM emp WHERE age<60 GROUP BY gender;

查询所有年龄小于等于 35 岁员工的姓名和年龄，并对查询结果按年龄升序排序，如果年龄相同按入职时间降序排序。

SELECT name,age FROM emp WHERE age<=35 ORDER BY age ASC,entrydate DESC;

查询性别为男，且年龄在 20-40 岁(含)以内的前 5 个员工信息，对查询的结果按年龄升序排序，年龄相同按入职时间升序排序。

SELECT * FROM emp WHERE gender='男' AND age BETWEEN 20 AND 40 ORDER BY age ASC,entrydate ASC LIMIT 5;

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