表名和字段
學生表
Student(s_id,s_name,s_birth,s_sex)：學生編號、學生姓名、出生年月、學生性別。
課程表
Course(c_id,c_name,t_id)：課程編號、課程名稱、教師編號。
教師表
Teacher(t_id,t_name)：教師編號、教師姓名。
成績表
Score(s_id,c_id,s_score)：學生編號、課程編號、分數。
建表語句
# 建表
# 學生表
CREATE TABLE `student`(
`s_id` VARCHAR(20),
`s_name` VARCHAR(20) NOT NULL DEFAULT '',
`s_birth` VARCHAR(20) NOT NULL DEFAULT '',
`s_sex` VARCHAR(10) NOT NULL DEFAULT '',
PRIMARY KEY(`s_id`)
);
# 課程表
CREATE TABLE `course`(
`c_id` VARCHAR(20),
`c_name` VARCHAR(20) NOT NULL DEFAULT '',
`t_id` VARCHAR(20) NOT NULL,
PRIMARY KEY(`c_id`)
);
# 教師表
CREATE TABLE `teacher`(
`t_id` VARCHAR(20),
`t_name` VARCHAR(20) NOT NULL DEFAULT '',
PRIMARY KEY(`t_id`)
);
# 成績表
CREATE TABLE `score`(
`s_id` VARCHAR(20),
`c_id` VARCHAR(20),
`s_score` INT(3),
PRIMARY KEY(`s_id`,`c_id`)
);
# 插入數據
# 插入學生表測試數據
insert into Student values('1', '趙雷', '1990-01-01', '男');
insert into Student values('2', '錢電', '1990-12-21', '男');
insert into Student values('3', '孫風', '1990-05-20', '男');
insert into Student values('4', '李雲', '1990-08-06', '男');
insert into Student values('5', '周梅', '1991-12-01', '女');
insert into Student values('6', '吳蘭', '1992-03-01', '女');
insert into Student values('7', '鄭竹', '1989-07-01', '女');
insert into Student values('8', '王菊', '1990-01-20', '女');
# 插入課程表測試數據
insert into Course values('1', '語文', '2');
insert into Course values('2', '數學', '1');
insert into Course values('3', '英語', '3');
# 插入教師表測試數據
insert into Teacher values('1', '張三');
insert into Teacher values('2', '李四');
insert into Teacher values('3', '王五');
# 插入成績表測試數據
insert into Score values('1', '1', 80);
insert into Score values('1', '2', 90);
insert into Score values('1', '3', 99);
insert into Score values('2', '1', 70);
insert into Score values('2', '2', 60);
insert into Score values('2', '3', 80);
insert into Score values('3', '1', 80);
insert into Score values('3', '2', 80);
insert into Score values('3', '3', 80);
insert into Score values('4', '1', 50);
insert into Score values('4', '2', 30);
insert into Score values('4', '3', 20);
insert into Score values('5', '1', 76);
insert into Score values('5', '2', 87);
insert into Score values('6', '1', 31);
insert into Score values('6', '3', 34);
insert into Score values('7', '2', 89);
insert into Score values('7', '3', 98);
題目及答案
# 1.查詢"1"課程比"2"課程成績高的學生的信息及課程分數。
SELECT
student.*,
s1.s_score AS "語文成績",
s2.s_score AS "數學成績"
FROM
student
LEFT JOIN
score AS s1
ON
student.s_id = s1.s_id AND s1.c_id = 1
LEFT JOIN
score AS s2
ON
student.s_id = s2.s_id AND s2.c_id = 2
WHERE
s1.s_score > s2.s_score;
# 2.查詢"1"課程比"2"課程成績低的學生的信息及課程分數。
SELECT
student.*,
s1.s_score AS "語文成績",
s2.s_score AS "數學成績"
FROM
student
LEFT JOIN
score AS s1
ON
s1.s_id = student.s_id AND s1.c_id = 1
LEFT JOIN
score AS s2
ON
s2.s_id = student.s_id AND s2.c_id = 2
WHERE
s1.s_score < s2.s_score;
# 3.查詢平均成績大於等於60分的同學的學生編號和學生姓名和平均成績。
SELECT
student.s_id AS "學生編號",
student.s_name AS "學生姓名",
ROUND(AVG(score.s_score),2) AS "平均成績"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
AVG(score.s_score) >= 60;
# 4.查詢平均成績小於60分的同學的學生編號和學生姓名和平均成績（包括有成績的和無成績的）。
SELECT
student.s_id AS "學生編號",
student.s_name AS "學生姓名",
IFNULL(ROUND(AVG(score.s_score),2),0) AS "平均成績"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
AVG(score.s_score) < 60 OR AVG(score.s_score) IS NULL;
# 5.查詢所有同學的學生編號、學生姓名、選課總數、所有課程的總成績。
SELECT
student.s_id AS "學生編號",
student.s_name AS "學生姓名",
COUNT(course.c_id) AS "選課總數",
IFNULL(SUM(score.s_score),0) AS "所有課程總成績"
FROM
student
LEFT JOIN
score
ON
student.s_id = score.s_id
LEFT JOIN
course
ON
course.c_id = score.c_id
GROUP BY
student.s_id;
# 6.查詢"李"姓老師的數量。
SELECT
COUNT(t_id)
FROM
teacher
WHERE
t_name LIKE "李%";
# 7.查詢學過"張三"老師授課的同學的信息。
SELECT
student.*
FROM
student
LEFT JOIN
score
ON
student.s_id = score.s_id
LEFT JOIN
course
ON
score.c_id = course.c_id
LEFT JOIN
teacher
ON
course.t_id = teacher.t_id
WHERE
teacher.t_name = "張三";
# 8.查詢沒學過"張三"老師授課的同學的信息。
SELECT
student.*
FROM
student
WHERE
student.s_id NOT IN
(
SELECT
student.s_id
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
WHERE
score.c_id IN
(
SELECT
course.c_id
FROM
course
LEFT JOIN
teacher
ON
course.t_id = teacher.t_id
WHERE
teacher.t_name = "張三"
)
)
# 9.查詢學過編號為"1"並且也學過編號為"2"的課程的同學的信息。
SELECT
student.*
FROM
student
INNER JOIN
score
ON
score.s_id = student.s_id
INNER JOIN
course
ON
course.c_id = score.c_id
GROUP BY
student.s_id
HAVING
SUM(IF(course.c_id = 1 OR course.c_id = 2, 1, 0)) > 1;
# 10.查詢學過編號為"1"但是沒有學過編號為"2"的課程的同學的信息。
SELECT
student.*
FROM
student
INNER JOIN
score
ON
score.s_id = student.s_id AND score.c_id = 1
WHERE
student.s_id NOT IN
(
SELECT
student.s_id
FROM
student
INNER JOIN
score
ON
score.s_id = student.s_id AND score.c_id = 2
);
# 11.查詢沒有學全所有課程的同學的信息。
SELECT
student.*
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
COUNT(c_id) < (
SELECT
COUNT(c_id)
FROM
course
);
# 12.查詢至少有一門課與學號為"1的同學所學相同的同學的信息。
SELECT
student.*
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
WHERE
c_id IN (
SELECT
c_id
FROM
score
LEFT JOIN
student
ON
score.s_id = student.s_id
WHERE
student.s_id = 1
)
GROUP BY
student.s_id;
# 13.查詢和"1"號的同學學習的課程完全相同的其他同學的信息。
SELECT
student.*
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
GROUP_CONCAT(c_id) = (
SELECT
GROUP_CONCAT(c_id)
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
student.s_id = 1
);
# 14.查詢沒學過"張三"老師講授的任一門課程的學生姓名。
SELECT
s_name
FROM
student
WHERE
s_id NOT IN (
SELECT
s_id
FROM
score
INNER JOIN
course
ON
course.c_id = score.c_id
INNER JOIN
teacher
ON
teacher.t_id = course.t_id AND t_name = "張三"
);
# 15.查詢兩門及其以上不及格課程的同學的學號，姓名及其平均成績。
SELECT
student.s_id AS "學號",
s_name AS "姓名",
IFNULL(ROUND(AVG(s_score),2),0) AS "平均成績"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
SUM(IF(s_score < 60, 1, 0)) >= 2;
SELECT st.s_id,st.s_name, sc.* FROM score AS sc LEFT JOIN student AS st ON sc.s_id = st.s_id WHERE sc.s_score < 60 GROUP BY sc.s_id;
# 16.檢索"1"課程分數小於60，按分數降序排列的學生信息。
SELECT
student.*,
s_score AS "分數"
FROM
student
INNER JOIN
score
ON
score.s_id = student.s_id AND c_id = 1
WHERE
s_score < 60
ORDER BY
s_score DESC;
# 17.按平均成績從高到低顯示所有學生的所有課程的成績以及平均成績。
SELECT
s_name,
IFNULL(s1.s_score, 0) AS "語文成績",
IFNULL(s2.s_score, 0) AS "數學成績",
IFNULL(s3.s_score, 0) AS "英語成績",
IFNULL(ROUND(AVG(s4.s_score), 2), 0) AS "平均成績"
FROM
student
LEFT JOIN
score AS s1
ON
s1.s_id = student.s_id AND s1.c_id = 1
LEFT JOIN
score AS s2
ON
s2.s_id = student.s_id AND s2.c_id = 2
LEFT JOIN
score AS s3
ON
s3.s_id = student.s_id AND s3.c_id = 3
LEFT JOIN
score AS s4
ON
s4.s_id = student.s_id
GROUP BY
student.s_id
ORDER BY
AVG(s4.s_score) DESC;
# 18.查詢各科成績最高分、最低分和平均分：以如下形式顯示：課程ID，課程name，最高分，最低分，平均分，及格率，中等率，優良率，優秀率。
# 及格為>=60，中等為：70-80，優良為：80-90，優秀為：>=90。
SELECT
course.c_id AS "課程ID",
c_name AS "課程名稱",
MAX(s_score) AS "最高分",
MIN(s_score) AS "最低分",
AVG(s_score) AS "平均分",
(SUM(IF(s_score >= 60, 1, 0)) / COUNT(1)) AS "及格率",
(SUM(IF(s_score >= 70 AND s_score < 80, 1, 0)) / COUNT(1)) AS "中等率",
(SUM(IF(s_score >= 80 AND s_score < 90, 1, 0)) / COUNT(1)) AS "優良率",
(SUM(IF(s_score >= 90, 1, 0)) / COUNT(1)) AS "優秀率"
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
GROUP BY
course.c_id;
# 19.按各科成績進行排序，並顯示排名。
SELECT
c_name AS "課程名稱",
s_score AS "分數",
(
CASE
WHEN @p = s_score THEN @rank
WHEN @p := s_score THEN @rank := @rank + 1
END
) AS "排名"
FROM
(
SELECT
c_name,
s_score
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
WHERE
course.c_id = 1
ORDER BY
s_score DESC
) AS tab,
(SELECT @rank := 0, @p := NULL) AS r
UNION ALL
SELECT
c_name AS "課程名稱",
s_score AS "分數",
(
CASE
WHEN @p2 = s_score THEN @rank2
WHEN @p2 := s_score THEN @rank2 := @rank2 + 1
END
) AS "排名"
FROM
(
SELECT
c_name,
s_score
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
WHERE
course.c_id = 2
ORDER BY
s_score DESC
) AS tab,
(SELECT @rank2 := 0, @p2 := NULL) AS r
UNION ALL
SELECT
c_name AS "課程名稱",
s_score AS "分數",
(
CASE
WHEN @p3 = s_score THEN @rank3
WHEN @p3 := s_score THEN @rank3 := @rank3 + 1
END
) AS "排名"
FROM
(
SELECT
c_name,
s_score
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
WHERE
course.c_id = 3
ORDER BY
s_score DESC
) AS tab,
(SELECT @rank3 := 0, @p3 := NULL) AS r;
# 20.查詢學生的總成績並進行排名。
SELECT
s_name AS "學生姓名",
IFNULL(SUM(s_score), 0) AS "總成績"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
ORDER BY
SUM(s_score) DESC;
# 21.查詢不同老師所教不同課程平均分從高到低顯示。
SELECT
teacher.t_name AS "老師姓名",
c_name AS "課程名稱",
AVG(s_score) AS "平均分"
FROM
teacher
INNER JOIN
course
ON
course.t_id = teacher.t_id
INNER JOIN
score
ON
score.c_id = course.c_id
GROUP BY
course.c_id
ORDER BY
AVG(s_score) DESC;
# 22.查詢所有課程的成績第2名到第3名的學生信息及該課程成績。
(SELECT
c_name AS "課程名稱",
student.*,
s_score AS "分數"
FROM
student
INNER JOIN
score
ON
student.s_id = score.s_id
INNER JOIN
course
ON
course.c_id = score.c_id AND course.c_id = 1
ORDER BY
s_score DESC
LIMIT 1, 2)
UNION ALL
(SELECT
c_name AS "課程名稱",
student.*,
s_score AS "分數"
FROM
student
INNER JOIN
score
ON
student.s_id = score.s_id
INNER JOIN
course
ON
course.c_id = score.c_id AND course.c_id = 2
ORDER BY
s_score DESC
LIMIT 1, 2)
UNION ALL
(SELECT
c_name AS "課程名稱",
student.*,
s_score AS "分數"
FROM
student
INNER JOIN
score
ON
student.s_id = score.s_id
INNER JOIN
course
ON
course.c_id = score.c_id AND course.c_id = 3
ORDER BY
s_score DESC
LIMIT 1, 2);
# 23.統計各科成績各分數段人數：課程編號，課程名稱，[100-85]，[85-70]，[70-60]，[0-60]及所占百分比。
SELECT
course.c_id AS "課程編號",
c_name AS "課程名稱",
SUM(IF(s_score > 85 AND s_score <= 100, 1, 0)) AS "[85-100]人數",
(SUM(IF(s_score > 85 AND s_score <= 100, 1, 0)) / COUNT(1)) AS "所百分比",
SUM(IF(s_score > 70 AND s_score <= 85, 1, 0)) AS "[70-85]人數",
(SUM(IF(s_score > 70 AND s_score <= 85, 1, 0)) / COUNT(1)) AS "所百分比",
SUM(IF(s_score > 60 AND s_score <= 70, 1, 0)) AS "[60-70]人數",
(SUM(IF(s_score > 60 AND s_score <= 70, 1, 0)) / COUNT(1)) AS "所百分比",
SUM(IF(s_score <= 60, 1, 0)) AS "[0-60]人數",
(SUM(IF(s_score <= 60, 1, 0)) / COUNT(1)) AS "所百分比"
FROM
score
INNER JOIN
course
ON
score.c_id = course.c_id
GROUP BY
course.c_id;
# 24.查詢學生平均成績及其名次。
SELECT
s_name AS "學生姓名",
avg AS "平均分",
(
CASE
WHEN @p = avg THEN @rank
WHEN @p := avg THEN @rank := @rank + 1
END
) AS "排名"
FROM
(
SELECT
s_name,
ROUND(IFNULL(AVG(s_score), 0), 2) AS avg
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
ORDER BY
AVG(s_score) DESC
) AS tab,
(SELECT @rank := 0, @p := NULL) AS r;
# 25.查詢各科成績前三名的記錄。
(SELECT
c_name AS "課程名稱",
s_score AS "分數"
FROM
score
INNER JOIN
course
ON
course.c_id = score.c_id AND course.c_id = 1
ORDER BY
s_score DESC
LIMIT 3)
UNION ALL
(SELECT
c_name AS "課程名稱",
s_score AS "分數"
FROM
score
INNER JOIN
course
ON
course.c_id = score.c_id AND course.c_id = 2
ORDER BY
s_score DESC
LIMIT 3)
UNION ALL
(SELECT
c_name AS "課程名稱",
s_score AS "分數"
FROM
score
INNER JOIN
course
ON
course.c_id = score.c_id AND course.c_id = 3
ORDER BY
s_score DESC
LIMIT 3)
# 26.查詢每門課程被選修的學生數。
SELECT
c_name AS "課程名稱",
COUNT(s_id) AS "人數"
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
GROUP BY
course.c_id;
# 27.查詢出只有兩門課程的全部學生的學號和姓名。
SELECT
student.s_id AS "學號",
s_name AS "姓名"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
COUNT(score.c_id) = 2;
# 28.查詢男生、女生人數。
SELECT
s_sex AS "性別",
COUNT(s_sex) AS "人數"
FROM
student
GROUP BY
s_sex;
# 29.查詢名字中含有"風"字的學生信息。
SELECT
*
FROM
student
WHERE
s_name LIKE "%風%";
# 30.查詢同名同性學生名單，並統計同名人數。
SELECT
s_name AS "姓名",
s_sex AS "性別",
COUNT(s_name) AS "人數"
FROM
student
GROUP BY
s_name,
s_sex
HAVING
COUNT(s_name) > 1;
# 31.查詢1990年出生的學生名單。
SELECT
s_name AS "姓名"
FROM
student
WHERE
s_birth LIKE "1990%";
# 32.查詢每門課程的平均成績，結果按平均成績降序排列，平均成績相同時，按課程編號升序排列。
SELECT
course.c_id AS "課程編號",
c_name AS "課程名稱",
ROUND(AVG(s_score), 2) AS "平均成績"
FROM
score
INNER JOIN
course
ON
course.c_id = score.c_id
GROUP BY
course.c_id
ORDER BY
AVG(s_score) DESC,
course.c_id ASC;
# 33.查詢平均成績大於等於85的所有學生的學號、姓名和平均成績。
SELECT
student.s_id AS "編號",
s_name AS "姓名",
ROUND(AVG(s_score), 2) AS "平均成績"
FROM
student
LEFT JOIN
score
ON
student.s_id = score.s_id
GROUP BY
student.s_id
HAVING
AVG(s_score) >= 85;
# 34.查詢課程名稱為"數學"，且分數低於60的學生姓名和分數。
SELECT
s_name AS "學生姓名",
s_score AS "分數"
FROM
student
INNER JOIN
score
ON
student.s_id = score.s_id
INNER JOIN
course
ON
course.c_id = score.c_id AND c_name = "數學"
WHERE
s_score < 60;
# 35.查詢所有學生的課程及分數情況。
SELECT
student.s_id AS "學號",
s_name AS "姓名",
c_name AS "課程名稱",
IFNULL(s_score, 0) AS "分數"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
LEFT JOIN
course
ON
course.c_id = score.c_id;
# 36.查詢任何一門課程成績在70分以上的姓名、課程名稱和分數。
SELECT
s_name AS "姓名",
c_name AS "課程名稱",
s_score AS "分數"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
LEFT JOIN
course
ON
course.c_id = score.c_id
WHERE
s_score > 70;
# 37.查詢不及格的課程。
SELECT
c_name AS "課程名稱",
s_score AS "分數"
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
WHERE
s_score < 60;
# 38.查詢課程編號為"1程成績在80分以上的學生的學號和姓名。
SELECT
student.s_id AS "學號",
s_name AS "姓名"
FROM
student
INNER JOIN
score
ON
score.s_id = student.s_id AND c_id = 1 AND s_score >= 80;
# 39.求每門課程的學生人數。
SELECT
c_name AS "課程名稱",
COUNT(s_id) AS "學生人數"
FROM
course
INNER JOIN
score
ON
score.c_id = course.c_id
GROUP BY
course.c_id;
# 40.查詢選修"張三"老師所授課程的學生中，成績最高的學生信息及其成績。
SELECT
student.*,
s_score AS "分數"
FROM
student
INNER JOIN
score
ON
score.s_id = student.s_id
INNER JOIN
course
ON
course.c_id = score.c_id
INNER JOIN
teacher
ON
teacher.t_id = course.t_id
WHERE
t_name = "張三"
ORDER BY
s_score DESC
LIMIT 1;
# 41.查詢不同課程成績相同的學生的學生編號、課程編號、學生成績。
SELECT
student.s_id AS "學生學號",
s_name AS "學生姓名",
s1.c_id AS "課程編號",
s1.s_score AS "分數"
FROM
student
LEFT JOIN
score AS s1
ON
s1.s_id = student.s_id
LEFT JOIN
course AS c1
ON
c1.c_id = s1.c_id
WHERE
(
SELECT
COUNT(1)
FROM
student
LEFT JOIN
score AS s2
ON
s2.s_id = student.s_id
LEFT JOIN
course AS c2
ON
c2.c_id = s2.c_id
WHERE
s1.s_score = s2.s_score
AND
c1.c_id != c2.c_id
) > 1;
# 42.查詢每門功成績最好的前兩名。
(
SELECT
c_name AS "課程名稱",
s_name AS "學生姓名",
s_score AS "分數"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
LEFT JOIN
course
ON
course.c_id = score.c_id
WHERE
course.c_id = 1
LIMIT 2
)
UNION ALL
(
SELECT
c_name AS "課程名稱",
s_name AS "學生姓名",
s_score AS "分數"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
LEFT JOIN
course
ON
course.c_id = score.c_id
WHERE
course.c_id = 2
LIMIT 2
)
UNION ALL
(
SELECT
c_name AS "課程名稱",
s_name AS "學生姓名",
s_score AS "分數"
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
LEFT JOIN
course
ON
course.c_id = score.c_id
WHERE
course.c_id = 3
LIMIT 2
);
# 43.統計每門課程的學生選修人數（超過5人的課程才統計）。要求輸出課程號和選修人數，查詢結果按人數降序排列，若人數相同，按課程號升序排列。
SELECT
c_id AS "課程編號",
COUNT(s_score) AS "學生人數"
FROM
score
GROUP BY
c_id
HAVING
COUNT(s_score) > 5
ORDER BY
COUNT(s_score) DESC,
c_id ASC;
# 44.檢索至少選修兩門課程的學生學號。
SELECT
s_id AS "學號"
FROM
score
GROUP BY
s_id
HAVING
COUNT(c_id) >= 2;
# 45.查詢選修了全部課程的學生信息。
SELECT
student.*
FROM
student
LEFT JOIN
score
ON
score.s_id = student.s_id
GROUP BY
student.s_id
HAVING
COUNT(c_id) = (
SELECT
COUNT(1)
FROM
course
);
# 46.查詢各學生的年齡。
SELECT
s_name AS "姓名",
TIMESTAMPDIFF(YEAR, s_birth, NOW())
FROM
student;
# 47.查詢本周過生日的學生。
SELECT
student.*
FROM
student
WHERE
WEEK(NOW(), 1) = WEEK(CONCAT(YEAR(s_birth), '-', MONTH(s_birth), '-', DAY(s_birth)), 1);
# 48.查詢下周過生日的學生。
SELECT
student.*
FROM
student
WHERE
WEEK(NOW(), 1) = WEEK(CONCAT(YEAR(s_birth), '-', MONTH(s_birth), '-', DAY(s_birth)), 1) - 1;
# 49.查詢本月過生日的學生。
SELECT
student.*
FROM
student
WHERE
MONTH(NOW()) = MONTH(CONCAT(YEAR(s_birth), '-', MONTH(s_birth), '-', DAY(s_birth)));
# 50.查詢下月過生日的學生。
SELECT
student.*
FROM
student
WHERE
MONTH(NOW()) = MONTH(CONCAT(YEAR(s_birth), '-', MONTH(s_birth), '-', DAY(s_birth))) - 1;
如有問題或有更優寫法，歡迎大家留言提建議！