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mysql復(fù)雜查詢50題mysql面試題

2025-10-08 11:25 清風(fēng)軟件測(cè)試開發(fā) 閱讀(21) 評(píng)論(0) 收藏舉報(bào)

#–1.學(xué)生表 
#Student(s_id,s_name,s_birth,s_sex) –學(xué)生編號(hào),學(xué)生姓名, 出生年月,學(xué)生性別
CREATE TABLE `Student` (
    `s_id` VARCHAR(20),
    s_name VARCHAR(20) NOT NULL DEFAULT '',
    s_brith VARCHAR(20) NOT NULL DEFAULT '',
    s_sex VARCHAR(10) NOT NULL DEFAULT '',
    PRIMARY KEY(s_id)
);

#–2.課程表 
#Course(c_id,c_name,t_id) – –課程編號(hào), 課程名稱, 教師編號(hào) 
create table Course(
    c_id varchar(20),
    c_name VARCHAR(20) not null DEFAULT '',
    t_id VARCHAR(20) NOT NULL,
    PRIMARY KEY(c_id)
);

/*
–3.教師表 
Teacher(t_id,t_name) –教師編號(hào),教師姓名 
*/
CREATE TABLE Teacher(
    t_id VARCHAR(20),
    t_name VARCHAR(20) NOT NULL DEFAULT '',
    PRIMARY KEY(t_id)
);

/*
–4.成績(jī)表 
Score(s_id,c_id,s_score) –學(xué)生編號(hào),課程編號(hào),分?jǐn)?shù)
*/
Create table Score(
    s_id VARCHAR(20),
    c_id VARCHAR(20) not null default '',
    s_score INT(3),
    primary key(`s_id`,`c_id`)
);

#--插入學(xué)生表測(cè)試數(shù)據(jù)
#('01' , '趙雷' , '1990-01-01' , '男')
insert into Student values('01' , '趙雷' , '1990-01-01' , '男');
insert into Student values('02' , '錢電' , '1990-12-21' , '男');
insert into Student values('03' , '孫風(fēng)' , '1990-05-20' , '男');
insert into Student values('04' , '李云' , '1990-08-06' , '男');
insert into Student values('05' , '周梅' , '1991-12-01' , '女');
insert into Student values('06' , '吳蘭' , '1992-03-01' , '女');
insert into Student values('07' , '鄭竹' , '1989-07-01' , '女');
insert into Student values('08' , '王菊' , '1990-01-20' , '女');

#--課程表測(cè)試數(shù)據(jù)
insert into Course values('01' , '語(yǔ)文' , '02');
insert into Course values('02' , '數(shù)學(xué)' , '01');
insert into Course values('03' , '英語(yǔ)' , '03');

#--教師表測(cè)試數(shù)據(jù)
insert into Teacher values('01' , '張三');
insert into Teacher values('02' , '李四');
insert into Teacher values('03' , '王五');

#--成績(jī)表測(cè)試數(shù)據(jù)
insert into Score values('01' , '01' , 80);
insert into Score values('01' , '02' , 90);
insert into Score values('01' , '03' , 99);
insert into Score values('02' , '01' , 70);
insert into Score values('02' , '02' , 60);
insert into Score values('02' , '03' , 80);
insert into Score values('03' , '01' , 80);
insert into Score values('03' , '02' , 80);
insert into Score values('03' , '03' , 80);
insert into Score values('04' , '01' , 50);
insert into Score values('04' , '02' , 30);
insert into Score values('04' , '03' , 20);
insert into Score values('05' , '01' , 76);
insert into Score values('05' , '02' , 87);
insert into Score values('06' , '01' , 31);
insert into Score values('06' , '03' , 34);
insert into Score values('07' , '02' , 89);
insert into Score values('07' , '03' , 98);

練習(xí)題和sql語(yǔ)句

主要分為四種：

1，數(shù)據(jù)對(duì)比：A比B多，A和B不同，A和B一樣，用同一個(gè)表的多個(gè)分身自連

2，求數(shù)量（附帶條件）和具體信息，用 join + group by + count + having

3，求排名，MySQL 8.0+ 使用 ROW_NUMBER() 或 RANK() 來(lái)實(shí)現(xiàn)分組排名

4，條件，用 in + 子查詢

-- 1、查詢"01"課程比"02"課程成績(jī)高的學(xué)生的信息及課程分?jǐn)?shù)

select a.*,b.s_score as score01,c.s_score as score02 FROM
　　student a
　　JOIN score b ON a.s_id=b.s_id and b.c_id='01'
　　LEFT JOIN score c on a.s_id=c.s_id and c.c_id='02' or c.c_id = NULL
WHERE b.s_score>c.s_score ;

-- 2、查詢"01"課程比"02"課程成績(jī)低的學(xué)生的信息及課程分?jǐn)?shù)
 
select a.* ,b.s_score as 01_score,c.s_score as 02_score from 
    student a left join score b on a.s_id=b.s_id and b.c_id='01' or b.c_id=NULL 
     join score c on a.s_id=c.s_id and c.c_id='02' where b.s_score<c.s_score
 
 
-- 3、查詢平均成績(jī)大于等于60分的同學(xué)的學(xué)生編號(hào)和學(xué)生姓名和平均成績(jī)
select b.s_id,b.s_name,ROUND(AVG(a.s_score),2) as avg_score from 
    student b 
    join score a on b.s_id = a.s_id
    GROUP BY b.s_id,b.s_name HAVING ROUND(AVG(a.s_score),2)>=60;
 
 
-- 4、查詢平均成績(jī)小于60分的同學(xué)的學(xué)生編號(hào)和學(xué)生姓名和平均成績(jī)
        -- (包括有成績(jī)的和無(wú)成績(jī)的)
 
select b.s_id,b.s_name,ROUND(AVG(a.s_score),2) as avg_score from 
    student b 
    left join score a on b.s_id = a.s_id
    GROUP BY b.s_id,b.s_name HAVING ROUND(AVG(a.s_score),2)<60
    union
select a.s_id,a.s_name,0 as avg_score from 
    student a 
    where a.s_id not in (
                select distinct s_id from score);
 
 
-- 5、查詢所有同學(xué)的學(xué)生編號(hào)、學(xué)生姓名、選課總數(shù)、所有課程的總成績(jī)
select a.s_id,a.s_name,count(b.c_id) as sum_course,sum(b.s_score) as sum_score from 
    student a 
    left join score b on a.s_id=b.s_id
    GROUP BY a.s_id,a.s_name;
 
 
-- 6、查詢"李"姓老師的數(shù)量 
select count(t_id) from teacher where t_name like '李%';
 
-- 7、查詢學(xué)過(guò)"張三"老師授課的同學(xué)的信息 
select a.* from 
    student a 
    join score b on a.s_id=b.s_id where b.c_id in(
        select c_id from course where t_id =(
            select t_id from teacher where t_name = '張三'));
 
-- 8、查詢沒學(xué)過(guò)"張三"老師授課的同學(xué)的信息 
select * from 
    student c 
    where c.s_id not in(
        select a.s_id from student a join score b on a.s_id=b.s_id where b.c_id in(
            select c_id from course where t_id =(
                select t_id from teacher where t_name = '張三')));
-- 9、查詢學(xué)過(guò)編號(hào)為"01"并且也學(xué)過(guò)編號(hào)為"02"的課程的同學(xué)的信息
 
select a.* from 
    student a,score b,score c 
    where a.s_id = b.s_id  and a.s_id = c.s_id and b.c_id='01' and c.c_id='02';
 
-- 10、查詢學(xué)過(guò)編號(hào)為"01"但是沒有學(xué)過(guò)編號(hào)為"02"的課程的同學(xué)的信息
 
select a.* from 
    student a 
    where a.s_id in (select s_id from score where c_id='01' ) and a.s_id not in(select s_id from score where c_id='02')
-- 11、查詢沒有學(xué)全所有課程的同學(xué)的信息 
select s.* from 
    student s where s.s_id in(
        select s_id from score where s_id not in(
            select a.s_id from score a 
                join score b on a.s_id = b.s_id and b.c_id='02'
                join score c on a.s_id = c.s_id and c.c_id='03'
            where a.c_id='01'))
-- 12、查詢至少有一門課與學(xué)號(hào)為"01"的同學(xué)所學(xué)相同的同學(xué)的信息 
select * from student where s_id in(
    select distinct a.s_id from score a where a.c_id in(select a.c_id from score a where a.s_id='01')
    );
 
-- 13、查詢和"01"號(hào)的同學(xué)學(xué)習(xí)的課程完全相同的其他同學(xué)的信息 
 
select a.* from student a where a.s_id in(
    select distinct s_id from score where s_id!='01' and c_id in(select c_id from score where s_id='01')
    group by s_id 
    having count(1)=(select count(1) from score where s_id='01'));
-- 14、查詢沒學(xué)過(guò)"張三"老師講授的任一門課程的學(xué)生姓名 
select a.s_name from student a where a.s_id not in (
    select s_id from score where c_id = 
                (select c_id from course where t_id =(
                    select t_id from teacher where t_name = '張三')) 
                group by s_id);
 
-- 15、查詢兩門及其以上不及格課程的同學(xué)的學(xué)號(hào)，姓名及其平均成績(jī) 
select a.s_id,a.s_name,ROUND(AVG(b.s_score)) from 
    student a 
    left join score b on a.s_id = b.s_id
    where a.s_id in(
            select s_id from score where s_score<60 GROUP BY  s_id having count(1)>=2)
    GROUP BY a.s_id,a.s_name
 
-- 16、檢索"01"課程分?jǐn)?shù)小于60，按分?jǐn)?shù)降序排列的學(xué)生信息
select a.*,b.c_id,b.s_score from 
    student a,score b 
    where a.s_id = b.s_id and b.c_id='01' and b.s_score<60 ORDER BY b.s_score DESC;
 
-- 17、按平均成績(jī)從高到低顯示所有學(xué)生的所有課程的成績(jī)以及平均成績(jī)
select a.s_id,(select s_score from score where s_id=a.s_id and c_id='01') as 語(yǔ)文,
                (select s_score from score where s_id=a.s_id and c_id='02') as 數(shù)學(xué),
                (select s_score from score where s_id=a.s_id and c_id='03') as 英語(yǔ),
            round(avg(s_score),2) as 平均分 from score a  GROUP BY a.s_id ORDER BY 平均分 DESC;
 
-- 18.查詢各科成績(jī)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(yōu)良率，優(yōu)秀率
--及格為>=60，中等為：70-80，優(yōu)良為：80-90，優(yōu)秀為：>=90
select a.c_id,b.c_name,MAX(s_score),MIN(s_score),ROUND(AVG(s_score),2),
    ROUND(100*(SUM(case when a.s_score>=60 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 及格率,
    ROUND(100*(SUM(case when a.s_score>=70 and a.s_score<=80 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 中等率,
    ROUND(100*(SUM(case when a.s_score>=80 and a.s_score<=90 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 優(yōu)良率,
    ROUND(100*(SUM(case when a.s_score>=90 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 優(yōu)秀率
    from score a left join course b on a.c_id = b.c_id GROUP BY a.c_id,b.c_name
-- 19、按各科成績(jī)進(jìn)行排序，并顯示排名(實(shí)現(xiàn)不完全)
-- mysql沒有rank函數(shù)
    select a.s_id,a.c_id,
        @i:=@i +1 as i保留排名,
        @k:=(case when @score=a.s_score then @k else @i end) as rank不保留排名,
        @score:=a.s_score as score
    from (
        select s_id,c_id,s_score from score WHERE c_id='01' GROUP BY s_id,c_id,s_score ORDER BY s_score DESC
)a,(select @k:=0,@i:=0,@score:=0)s
    union
    select a.s_id,a.c_id,
        @i:=@i +1 as i,
        @k:=(case when @score=a.s_score then @k else @i end) as rank,
        @score:=a.s_score as score
    from (
        select s_id,c_id,s_score from score WHERE c_id='02' GROUP BY s_id,c_id,s_score ORDER BY s_score DESC
)a,(select @k:=0,@i:=0,@score:=0)s
    union
    select a.s_id,a.c_id,
        @i:=@i +1 as i,
        @k:=(case when @score=a.s_score then @k else @i end) as rank,
        @score:=a.s_score as score
    from (
        select s_id,c_id,s_score from score WHERE c_id='03' GROUP BY s_id,c_id,s_score ORDER BY s_score DESC
)a,(select @k:=0,@i:=0,@score:=0)s
-- 20、查詢學(xué)生的總成績(jī)并進(jìn)行排名
select a.s_id,
    @i:=@i+1 as i,
    @k:=(case when @score=a.sum_score then @k else @i end) as rank,
    @score:=a.sum_score as score
from (select s_id,SUM(s_score) as sum_score from score GROUP BY s_id ORDER BY sum_score DESC)a,
    (select @k:=0,@i:=0,@score:=0)s
-- 21、查詢不同老師所教不同課程平均分從高到低顯示 
    select a.t_id,c.t_name,a.c_id,ROUND(avg(s_score),2) as avg_score from course a
        left join score b on a.c_id=b.c_id 
        left join teacher c on a.t_id=c.t_id
        GROUP BY a.c_id,a.t_id,c.t_name ORDER BY avg_score DESC;
-- 22、查詢所有課程的成績(jī)第2名到第3名的學(xué)生信息及該課程成績(jī)
 
            select d.*,c.排名,c.s_score,c.c_id from (
                select a.s_id,a.s_score,a.c_id,@i:=@i+1 as 排名 from score a,(select @i:=0)s where a.c_id='01'    
            )c
            left join student d on c.s_id=d.s_id
            where 排名 BETWEEN 2 AND 3
            UNION
            select d.*,c.排名,c.s_score,c.c_id from (
                select a.s_id,a.s_score,a.c_id,@j:=@j+1 as 排名 from score a,(select @j:=0)s where a.c_id='02'    
            )c
            left join student d on c.s_id=d.s_id
            where 排名 BETWEEN 2 AND 3
            UNION
            select d.*,c.排名,c.s_score,c.c_id from (
                select a.s_id,a.s_score,a.c_id,@k:=@k+1 as 排名 from score a,(select @k:=0)s where a.c_id='03'    
            )c
            left join student d on c.s_id=d.s_id
            where 排名 BETWEEN 2 AND 3;
 
 
-- 23、統(tǒng)計(jì)各科成績(jī)各分?jǐn)?shù)段人數(shù)：課程編號(hào),課程名稱,[100-85],[85-70],[70-60],[0-60]及所占百分比
 
 
        select distinct f.c_name,a.c_id,b.`85-100`,b.百分比,c.`70-85`,c.百分比,d.`60-70`,d.百分比,e.`0-60`,e.百分比 from score a
                left join (select c_id,SUM(case when s_score >85 and s_score <=100 then 1 else 0 end) as `85-100`,
                                            ROUND(100*(SUM(case when s_score >85 and s_score <=100 then 1 else 0 end)/count(*)),2) as 百分比
                                from score GROUP BY c_id)b on a.c_id=b.c_id
                left join (select c_id,SUM(case when s_score >70 and s_score <=85 then 1 else 0 end) as `70-85`,
                                            ROUND(100*(SUM(case when s_score >70 and s_score <=85 then 1 else 0 end)/count(*)),2) as 百分比
                                from score GROUP BY c_id)c on a.c_id=c.c_id
                left join (select c_id,SUM(case when s_score >60 and s_score <=70 then 1 else 0 end) as `60-70`,
                                            ROUND(100*(SUM(case when s_score >60 and s_score <=70 then 1 else 0 end)/count(*)),2) as 百分比
                                from score GROUP BY c_id)d on a.c_id=d.c_id
                left join (select c_id,SUM(case when s_score >=0 and s_score <=60 then 1 else 0 end) as `0-60`,
                                            ROUND(100*(SUM(case when s_score >=0 and s_score <=60 then 1 else 0 end)/count(*)),2) as 百分比
                                from score GROUP BY c_id)e on a.c_id=e.c_id
                left join course f on a.c_id = f.c_id
-- 24、查詢學(xué)生平均成績(jī)及其名次 
        select a.s_id,
                @i:=@i+1 as '不保留空缺排名',
                @k:=(case when @avg_score=a.avg_s then @k else @i end) as '保留空缺排名',
                @avg_score:=avg_s as '平均分'
        from (select s_id,ROUND(AVG(s_score),2) as avg_s from score GROUP BY s_id)a,(select @avg_score:=0,@i:=0,@k:=0)b;
-- 25、查詢各科成績(jī)前三名的記錄----mysql 8.0以上可以使用RANK()或者ROW_NUMBER()進(jìn)行排名：RANK() OVER (PARTITION BY c_id ORDER BY s_score DESC) AS rn
            -- 1.選出b表比a表成績(jī)大的所有組
            -- 2.選出比當(dāng)前id成績(jī)大的 小于三個(gè)的
        select a.s_id,a.c_id,a.s_score from score a 
            left join score b on a.c_id = b.c_id and a.s_score<b.s_score
            group by a.s_id,a.c_id,a.s_score HAVING COUNT(b.s_id)<3
            ORDER BY a.c_id,a.s_score DESC

或者

使用RANK()或者ROW_NUMBER()進(jìn)行排名：RANK() OVER (PARTITION BY c_id ORDER BY s_score DESC) AS rn

SELECT
　　s.s_name AS student_name,
　　c.c_name AS course_name,
　　sc.s_score AS score
FROM (
　　SELECT
　　s_id,
　　c_id,
　　s_score,
　　ROW_NUMBER() OVER (PARTITION BY c_id ORDER BY s_score DESC) AS rn
　　FROM score
) sc
　　JOIN student s ON sc.s_id = s.s_id
　　JOIN course c ON sc.c_id = c.c_id

WHERE sc.rn <= 3
　　ORDER BY c.c_name, sc.s_score DESC;



 
-- 26、查詢每門課程被選修的學(xué)生數(shù) 
 
        select c_id,count(s_id) from score a GROUP BY c_id
 
-- 27、查詢出只有兩門課程的全部學(xué)生的學(xué)號(hào)和姓名 
        select s_id,s_name from student where s_id in(
                select s_id from score GROUP BY s_id HAVING COUNT(c_id)=2);
 
-- 28、查詢男生、女生人數(shù) 
        select s_sex,COUNT(s_sex) as 人數(shù)  from student GROUP BY s_sex
 
-- 29、查詢名字中含有"風(fēng)"字的學(xué)生信息
 
        select * from student where s_name like '%風(fēng)%';
 
-- 30、查詢同名同性學(xué)生名單，并統(tǒng)計(jì)同名人數(shù) 
 
        select a.s_name,a.s_sex,count(*) from student a  JOIN 
                    student b on a.s_id !=b.s_id and a.s_name = b.s_name and a.s_sex = b.s_sex
        GROUP BY a.s_name,a.s_sex
 
 
 
-- 31、查詢1990年出生的學(xué)生名單
 
        select s_name from student where s_birth like '1990%'
 
-- 32、查詢每門課程的平均成績(jī)，結(jié)果按平均成績(jī)降序排列，平均成績(jī)相同時(shí)，按課程編號(hào)升序排列 
 
    select c_id,ROUND(AVG(s_score),2) as avg_score from score GROUP BY c_id ORDER BY avg_score DESC,c_id ASC
 
-- 33、查詢平均成績(jī)大于等于85的所有學(xué)生的學(xué)號(hào)、姓名和平均成績(jī) 
 
    select a.s_id,b.s_name,ROUND(avg(a.s_score),2) as avg_score from score a
        left join student b on a.s_id=b.s_id GROUP BY s_id HAVING avg_score>=85
 
-- 34、查詢課程名稱為"數(shù)學(xué)"，且分?jǐn)?shù)低于60的學(xué)生姓名和分?jǐn)?shù) 
 
        select a.s_name,b.s_score from score b LEFT JOIN student a on a.s_id=b.s_id where b.c_id=(
                    select c_id from course where c_name ='數(shù)學(xué)') and b.s_score<60
 
-- 35、查詢所有學(xué)生的課程及分?jǐn)?shù)情況； 
 
 
        select a.s_id,a.s_name,
                    SUM(case c.c_name when '語(yǔ)文' then b.s_score else 0 end) as '語(yǔ)文',
                    SUM(case c.c_name when '數(shù)學(xué)' then b.s_score else 0 end) as '數(shù)學(xué)',
                    SUM(case c.c_name when '英語(yǔ)' then b.s_score else 0 end) as '英語(yǔ)',
                    SUM(b.s_score) as  '總分'
        from student a left join score b on a.s_id = b.s_id 
        left join course c on b.c_id = c.c_id 
        GROUP BY a.s_id,a.s_name
 
 
 -- 36、查詢?nèi)魏我婚T課程成績(jī)?cè)?0分以上的姓名、課程名稱和分?jǐn)?shù)； 
            select a.s_name,b.c_name,c.s_score from course b left join score c on b.c_id = c.c_id
                left join student a on a.s_id=c.s_id where c.s_score>=70
 
 
 
-- 37、查詢不及格的課程
        select a.s_id,a.c_id,b.c_name,a.s_score from score a left join course b on a.c_id = b.c_id
            where a.s_score<60 
 
--38、查詢課程編號(hào)為01且課程成績(jī)?cè)?0分以上的學(xué)生的學(xué)號(hào)和姓名； 
        select a.s_id,b.s_name from score a LEFT JOIN student b on a.s_id = b.s_id
            where a.c_id = '01' and a.s_score>80
 
-- 39、求每門課程的學(xué)生人數(shù) 
        select count(*) from score GROUP BY c_id;
 
-- 40、查詢選修"張三"老師所授課程的學(xué)生中，成績(jī)最高的學(xué)生信息及其成績(jī)
 
 
        -- 查詢老師id   
        select c_id from course c,teacher d where c.t_id=d.t_id and d.t_name='張三'
        -- 查詢最高分（可能有相同分?jǐn)?shù)）
        select MAX(s_score) from score where c_id='02'
        -- 查詢信息
        select a.*,b.s_score,b.c_id,c.c_name from student a
            LEFT JOIN score b on a.s_id = b.s_id
            LEFT JOIN course c on b.c_id=c.c_id
            where b.c_id =(select c_id from course c,teacher d where c.t_id=d.t_id and d.t_name='張三')
            and b.s_score in (select MAX(s_score) from score where c_id='02')
-- 41、查詢不同課程成績(jī)相同的學(xué)生的學(xué)生編號(hào)、課程編號(hào)、學(xué)生成績(jī) 
    select DISTINCT b.s_id,b.c_id,b.s_score from score a,score b where a.c_id != b.c_id and a.s_score = b.s_score
-- 42、查詢每門功成績(jī)最好的前兩名 
        -- 牛逼的寫法
    select a.s_id,a.c_id,a.s_score from score a
        where (select COUNT(1) from score b where b.c_id=a.c_id and b.s_score>=a.s_score)<=2 ORDER BY a.c_id
-- 43、統(tǒng)計(jì)每門課程的學(xué)生選修人數(shù)（超過(guò)5人的課程才統(tǒng)計(jì)）。要求輸出課程號(hào)和選修人數(shù)，查詢結(jié)果按人數(shù)降序排列，若人數(shù)相同，按課程號(hào)升序排列  
        select c_id,count(*) as total from score GROUP BY c_id HAVING total>5 ORDER BY total,c_id ASC
-- 44、檢索至少選修兩門課程的學(xué)生學(xué)號(hào) 
        select s_id,count(*) as sel from score GROUP BY s_id HAVING sel>=2
-- 45、查詢選修了全部課程的學(xué)生信息 
        select * from student where s_id in(        
            select s_id from score GROUP BY s_id HAVING count(*)=(select count(*) from course))
--46、查詢各學(xué)生的年齡
    -- 按照出生日期來(lái)算，當(dāng)前月日 < 出生年月的月日則，年齡減一
    select s_birth,(DATE_FORMAT(NOW(),'%Y')-DATE_FORMAT(s_birth,'%Y') - 
                (case when DATE_FORMAT(NOW(),'%m%d')>DATE_FORMAT(s_birth,'%m%d') then 0 else 1 end)) as age
        from student;
 
 
-- 47、查詢本周過(guò)生日的學(xué)生
    select * from student where WEEK(DATE_FORMAT(NOW(),'%Y%m%d'))=WEEK(s_birth)
    select * from student where YEARWEEK(s_birth)=YEARWEEK(DATE_FORMAT(NOW(),'%Y%m%d'))
 
    select WEEK(DATE_FORMAT(NOW(),'%Y%m%d'))
 
-- 48、查詢下周過(guò)生日的學(xué)生
    select * from student where WEEK(DATE_FORMAT(NOW(),'%Y%m%d'))+1 =WEEK(s_birth)
 
-- 49、查詢本月過(guò)生日的學(xué)生
 
    select * from student where MONTH(DATE_FORMAT(NOW(),'%Y%m%d')) =MONTH(s_birth)
 
-- 50、查詢下月過(guò)生日的學(xué)生
    select * from student where MONTH(DATE_FORMAT(NOW(),'%Y%m%d'))+1 =MONTH(s_birth)

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