SELECT*
FROM t_book
WHERE book_copy IN(5,6,7);
SELECT*
FROM t_press
WHERE press_address LIKE'%北京%';
SELECT*
FROM t_reader
WHERE reader_borrowtotal IS NULL LIMIT 2,4;
SELECT AVG (YEAR(CURDATE())-YEAR(reader_birthday)) AS 平均年龄,
MIN(YEAR(CURDATE())-YEAR(reader_birthday)) AS 最小年龄,
MAX(YEAR(CURDATE())-YEAR(reader_birthday))AS 最大年龄,
COUNT(reader_id) AS 读者人数
FROM t_reader;
作业题：
图片来源：嘉杰
正确作业代码班上同学已经发在班级群里，我这个不一定正确，我主要分享这两张表✌️
/*SELECT *,borndate
FROM student
WHERE GradeId="1"
*/
SELECT *
FROM student
WHERE GradeId=1
ORDER BY borndate;
SELECT *
FROM result
WHERE SubjectNo=1
ORDER BY StudentResult DESC;
SELECT StudentNo,studentResult FROM result
WHERE ExamDate='2016-02-17'
ORDER BY studentresult DESC LIMIT 5;
SELECT COUNT(*),borndate FROM student GROUP BY YEAR(BORNDATE)
HAVING COUNT(*)>=2
SELECT studentName,FLOOR(DATEDIFF(NOW(),bornDate)/365) FROM student
WHERE sex='女'
ORDER BY bornDate DESC LIMIT 1,7;
SELECT MAX(studentresult),MIN(studentresult),MAX(studentresult)
FROM result WHERE
examDate='2016-02-17';
两张数据库表打包下载：
符攀飞