前言

mysql高级SQL语句主要学习select语句

本章主要三个板块：

mysql进阶查询
mysql数据库函数
mysql存储过程

#准备实验所需的两张表
use stevelu;
create table location (Region char(20),Store_Name char(20));
insert into location values('East','Boston');
insert into location values('East','New York');
insert into location values('West','Los Angeles');
insert into location values('West','Houston');
mysql> select * from location ;
+--------+-------------+
| region | store_name  |
+--------+-------------+
| East   | Boston      |
| East   | New York    |
| West   | Los Angeles |
| West   | Houstion    |
+--------+-------------+

create table store_info (Store_Name char(20),Sales int(10),Date char(10));
insert into store_info values('Los Angeles','1500','2020-12-05');
insert into store_info values('Houston','250','2020-12-07');
insert into store_info values('Los Angeles','300','2020-12-08');
insert into store_info values('Boston','700','2020-12-08');
mysql> select * from store_info;
+-------------+-------+------------+
| Store_Name  | Sales | Date       |
+-------------+-------+------------+
| Los Angeles |  1500 | 2020-12-05 |
| Houston     |   250 | 2020-12-07 |
| Los Angeles |   300 | 2020-12-08 |
| Boston      |   700 | 2020-12-08 |
+-------------+-------+------------+

一、mysql进阶查询（1）

1.1 SELECT

---- SELECT ----显示表格中一个或数个字段的所有数据记录
语法：SELECT "字段" FROM "表名";

#查询表中的指定字段
mysql> SELECT Store_Name FROM store_info;
+-------------+
| Store_Name  |
+-------------+
| Los Angeles |
| Houston     |
| Los Angeles |
| Boston      |
+-------------+

#查询时可以把字段重新排序
mysql> select date,Store_Name,Sales from store_info;
+------------+-------------+-------+
| date       | Store_Name  | Sales |
+------------+-------------+-------+
| 2020-12-05 | Los Angeles |  1500 |
| 2020-12-07 | Houston     |   250 |
| 2020-12-08 | Los Angeles |   300 |
| 2020-12-08 | Boston      |   700 |
+------------+-------------+-------+

在这里插入图片描述

1.2 DISTINCT

---- DISTINCT ----不显示重复的数据记录
语法：SELECT DISTINCT "字段" FROM "表名";

#不显示重复记录（DISTINCT加在字段前面）
mysql> SELECT DISTINCT Store_Name FROM store_info;
+-------------+
| Store_Name  |
+-------------+
| Los Angeles |
| Houston     |
| Boston      |
+-------------+
mysql> SELECT DISTINCT Store_Name,date FROM store_info;
+-------------+------------+
| Store_Name  | date       |
+-------------+------------+
| Los Angeles | 2020-12-05 |
| Houston     | 2020-12-07 |
| Los Angeles | 2020-12-08 |
| Boston      | 2020-12-08 |
+-------------+------------+

在这里插入图片描述

1.3 WHERE

---- WHERE ----有条件查询
语法：SELECT "字段" FROM "表名" WHERE "条件";

#查询Store_Name为Houston的记录
mysql> select * from store_info where Store_Name='Houston';
+------------+-------+------------+
| Store_Name | Sales | Date       |
+------------+-------+------------+
| Houston    |   250 | 2020-12-07 |
+------------+-------+------------+

#查询Sales大于1000的Store_Name
mysql> SELECT Store_Name FROM store_info WHERE Sales > 1000;
+-------------+
| Store_Name  |
+-------------+
| Los Angeles |
+-------------+

在这里插入图片描述

1.4 AND OR

---- AND OR ----且 或
语法：SELECT "字段" FROM "表名" WHERE "条件1" {
   
   [AND|OR] "条件2"}+ ;
#查询sales大于500小于1000的store_name
mysql> select store_name from store_info where sales >500 and sales <1000;
+------------+
| store_name |
+------------+
| Boston     |
+------------+
#查看sales大于200小于500，或者大于1000，且和或同时有记得加括号，把括号里面作为一个整体优先看待
mysql> select store_name,sales from store_info where (sales >200 and sales <500) or sales>1000;
+-------------+-------+
| store_name  | sales |
+-------------+-------+
| Los Angeles |  1500 |
| Houston     |   250 |
| Los Angeles |   300 |
+-------------+-------+

在这里插入图片描述

1.5 IN

---- IN ----显示已知的值的数据记录
#括号里面的值作为一个池子，有匹配该字段的就显示（值要用单引号）
语法：SELECT "字段" FROM "表名" WHERE "字段" IN ('值1', '值2', ...);
#查询Store_Name等于'Los Angeles'或 'Houston'
mysql> SELECT * FROM store_info WHERE Store_Name IN ('Los Angeles', 'Houston');
+-------------+-------+------------+
| Store_Name  | Sales | Date       |
+-------------+-------+------------+
| Los Angeles |  1500 | 2020-12-05 |
| Houston     |   250 | 2020-12-07 |
| Los Angeles |   300 | 2020-12-08 |
+-------------+-------+------------+
3 rows in set (0.00 sec)

#查询Store_Name不等于'Los Angeles'或 'Houston' （与上述操作取反）
mysql> SELECT * FROM store_info WHERE Store_Name not IN ('Los Angeles', 'Houston');
+------------+-------+------------+
| Store_Name | Sales | Date       |
+------------+-------+------------+
| Boston     |   700 | 2020-12-08 |
+------------+-------+------------+
1 row in set (0.00 sec)

在这里插入图片描述

1.6 BETWEEN

---- BETWEEN ----显示两个值范围内的数据记录
语法：SELECT "字段" FROM "表名" WHERE "字段" BETWEEN '值1' AND '值2';（数值左小右大）
#查询date在'2020-12-06' 和 '2020-12-10'之间的记录
mysql> SELECT * FROM store_info WHERE Date BETWEEN '2020-12-06' AND '2020-12-10';
+-------------+-------+------------+
| Store_Name  | Sales | Date       |
+-------------+-------+------------+
| Houston     |   250 | 2020-12-07 |
| Los Angeles |   300 | 2020-12-08 |
| Boston      |   700 | 2020-12-08 |
+-------------+-------+------------+
3 rows in set (0.00 sec)

在这里插入图片描述

1.7 通配符与like

----通配符----通常通配符都是跟 LIKE 一起使用的（与Linux的通配符不同）
---- LIKE ----匹配一个模式来找出我们要的数据记录
语法：SELECT "字段" FROM "表名" WHERE "字段" LIKE {模式};
SELECT * FROM Store_Info WHERE Store_Name like '%os%';
% ：百分号表示零个、一个或多个字符
_ ：下划线表示单个字符

'A_Z'：所有以 'A' 起头，另一个任何值的字符，且以 'Z' 为结尾的字符串。例如，'ABZ' 和 'A2Z' 都符合这一个模式，而 'AKKZ' 并不符合 (因为在 A 和 Z 之间有两个字符，而不是一个字符)。
'ABC%': 所有以 'ABC' 起头的字符串。例如，'ABCD' 和 'ABCABC' 都符合这个模式。
'%XYZ': 所有以 'XYZ' 结尾的字符串。例如，'WXYZ' 和 'ZZXYZ' 都符合这个模式。
'%AN%': 所有含有 'AN'这个模式的字符串。例如，'LOS ANGELES' 和 'SAN FRANCISCO' 都符合这个模式。
'_AN%'：所有第二个字母为 'A' 和第三个字母为 'N' 的字符串。例如，'SAN FRANCISCO' 符合这个模式，而 'LOS ANGELES' 则不符合这个模式。


#查询以on结尾的Store_Name的记录
mysql> select * from store_info where store_name like '%on';
+------------+-------+------------+
| Store_Name | Sales | Date       |
+------------+-------+------------+
| Houston    |   250 | 2020-12-07 |
| Boston     |   700 | 2020-12-08 |
+------------+-------+------------+
2 rows in set (0.00 sec)

在这里插入图片描述

1.7 ORDER BY

---- ORDER BY ----按关键字排序（通常是对数值排序）
语法：SELECT "字段" FROM "表名" [WHERE "条件"] ORDER BY "字段" [ASC, DESC];
#ASC 是按照升序进行排序的，是默认的排序方式。
#DESC 是按降序方式进行排序。

#对Sales值降序排序
mysql> SELECT Store_Name,Sales,Date FROM store_info ORDER BY Sales DESC;
+-------------+-------+------------+
| Store_Name  | Sales | Date       |
+-------------+-------+------------+
| Los Angeles |  1500 | 2020-12-05 |
| Boston      |   700 | 2020-12-08 |
| Los Angeles |   300 | 2020-12-08 |
| Houston     |   250 | 2020-12-07 |
+-------------+-------+------------+
4 rows in set (0.00 sec)

#对store_name值的字母升序排序
mysql> select * from store_info order by store_name;
+-------------+-------+------------+
| Store_Name  | Sales | Date       |
+-------------+-------+------------+
| Boston      |   700 | 2020-12-08 |
| Houston     |   250 | 2020-12-07 |
| Los Angeles |  1500 | 2020-12-05 |
| Los Angeles |   300 | 2020-12-08 |
+-------------+-------+------------+
4 rows in set (0.00 sec)

在这里插入图片描述

二、函数

2.1 数学函数

数学函数	含义
abs(x)	返回 x 的绝对值
rand()	返回 0 到 1 的随机数
mod(x,y)	返回 x 除以 y 以后的余数
power(x,y)	返回 x 的 y 次方
round(x)	返回离 x 最近的整数
round(x,y)	保留 x 的 y 位小数四舍五入后的值
sqrt(x)	返回 x 的平方根
truncate(x,y)	返回数字 x 截断为 y 位小数的值
ceil(x)	返回大于或等于 x 的最小整数
floor(x)	返回小于或等于 x 的最大整数
greatest(x1,x2…)	返回集合中最大的值，也可以返回多个字段的最大的值
least(x1,x2…)	返回集合中最小的值，也可以返回多个字段的最小的值

#只能对数值进行操作
mysql> SELECT abs(-1), rand(), mod(5,3), power(2,3), round(1.89);
+---------+--------------------+----------+------------+-------------+
| abs(-1) | rand()             | mod(5,3) | power(2,3) | round(1.89) |
+---------+--------------------+----------+------------+-------------+
|       1 | 0.2744006926886744 |        2 |          8 |           2 |
+---------+--------------------+----------+------------+-------------+

mysql> SELECT round(1.8937,3), truncate(1.235,2), ceil(5.2), floor(2.1), least(1.89,3,6.1,2.1);
+-----------------+-------------------+-----------+------------+-----------------------+
| round(1.8937,3) | truncate(1.235,2) | ceil(5.2) | floor(2.1) | least(1.89,3,6.1,2.1) |
+-----------------+-------------------+-----------+------------+-----------------------+
|           1.894 |              1.23 |         6 |          2 |                  1.89 |
+-----------------+-------------------+-----------+------------+-----------------------+
#对member表生成随机排序
mysql> select * from member order by rand();
+----+----------+--------+--------+---------+--------------------+
| id | name     | cardid | phone  | address | remark             |
+----+----------+--------+--------+---------+--------------------+
|  1 | zhangsan | 123123 | 123123 | nanjing | this is vip        |
|  3 | wangwu   | 123123 | 123123 | wuxi    | this is vvvip      |
|  4 | zhaoliu  | 123123 | 123123 | nantong | this is vip member |
|  2 | lisi     | 123123 | 123123 | suzhou  | this is vvip       |
+----+----------+--------+--------+---------+--------------------+
4 rows in set (0.00 sec)

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在这里插入图片描述

2.2 聚合函数

聚合函数	含义
avg()	返回指定列的平均值
count()	返回指定列中非 NULL 值的个数
min()	返回指定列的最小值
max()	返回指定列的最大值
sum(x)	返回指定列的所有值之和

#查询表中sales最大的
mysql> select max(sales) from store_info;
+------------+
| max(sales) |
+------------+
|       1500 |
+------------+
1 row in set (0.00 sec)

#查询表中sales最小的
mysql> select min(sales) from store_info;
+------------+
| min(sales) |
+------------+
|        250 |
+------------+
1 row in set (0.00 sec)

#也可以结合排序找最小值或者最大值
mysql> select sales from store_info order by sales asc limit 1;
+-------+
| sales |
+-------+
|   250 |
+-------+

#查询sales的平均值
mysql> select avg(sales) from store_info;
+------------+
| avg(sales) |
+------------+
|   687.5000 |
+------------+
1 row in set (0.00 sec)

#求sales值的和
mysql> select sum(sales) from store_info;
+------------+
| sum(sales) |
+------------+
|       2750 |
+------------+
1 row in set (0.00 sec)

在这里插入图片描述

新建一个city表，用来演示count()函数

create table city (name char(20));
insert into city values('nanjing');
insert into city values('hangzhou');
insert into city values('shanghai');
insert into city values();
insert into city values();
insert into city values('beijing');
insert into city values();
insert into city values();

#查询city表中的个数时，不会把空的记录算进去
mysql> select count(name) from city;
+-------------+
| count(name) |
+-------------+
|           4 |
+-------------+
#查询个数时，打上*，就不会忽略空行
mysql> select count(*) from city;
+----------+
| count(*) |
+----------+
|        8 |
+----------+

在这里插入图片描述

2.3 字符串函数

字符串函数	含义
trim()	返回去除指定格式的值
concat(x,y)	将提供的参数 x 和 y 拼接成一个字符串
substr(x,y)	获取从字符串 x 中的第 y 个位置开始的字符串，跟substring()函数作用相同
substr(x,y,z)	获取从字符串 x 中的第 y 个位置开始长度为 z 的字符串
length(x)	返回字符串 x 的长度
replace(x,y,z)	将字符串 z 替代字符串 x 中的字符串 y
upper(x)	将字符串 x 的所有字母变成大写字母
lower(x)	将字符串 x 的所有字母变成小写字母
left(x,y)	返回字符串 x 的前 y 个字符
right(x,y)	返回字符串 x 的后 y 个字符
repeat(x,y)	将字符串 x 重复 y 次
space(x)	返回 x 个空格
strcmp(x,y)	比较 x 和 y，返回的值可以为-1,0,1
reverse(x)	将字符串 x 反转

返回去除指定格式的值

SELECT TRIM ([ [位置] [要移除的字符串] FROM ] 字符串);
#[位置]：的值可以为 LEADING (起头), TRAILING (结尾), BOTH (起头及结尾)。 
#[要移除的字符串]：从字串的起头、结尾，或起头及结尾移除的字符串。缺省时为空格。

mysql> SELECT TRIM(LEADING 'Ne' FROM 'New York');
+------------------------------------+
| TRIM(LEADING 'Ne' FROM 'New York') |
+------------------------------------+
| w York                             |
+------------------------------------+
1 row in set (0.00 sec)

在这里插入图片描述

将提供的参数 x 和 y 拼接成一个字符串

mysql> select concat('zhang','san');
+-----------------------+
| concat('zhang','san') |
+-----------------------+
| zhangsan              |
+-----------------------+
---在zhangsan中间加个空格，就是添加一个空格字符串
mysql> select concat('zhang',' ','san');
+---------------------------+
| concat('zhang',' ','san') |
+---------------------------+
| zhang san                 |
+---------------------------+

mysql> select * from location;
+--------+-------------+
| region | store_name  |
+--------+-------------+
| East   | Boston      |
| East   | New York    |
| West   | Los Angeles |
| West   | Houstion    |
+--------+-------------+
4 rows in set (0.00 sec)
---对location表中的两个字段进行合并，注意不要加引号
mysql> select concat(region,store_name) from location;
+---------------------------+
| concat(region,store_name) |
+---------------------------+
| EastBoston                |
| EastNew York              |
| WestLos Angeles           |
| WestHoustion              |
+---------------------------+
4 rows in set (0.00 sec)

---如sql_mode开启了PIPES_AS_CONCAT，"||"视为字符串的连接操作符而非或运算符，和字符串的拼接函数Concat相类似，这和Oracle数据库使用方法一样的
SELECT Region || ' ' || Store_Name FROM location

在这里插入图片描述

获取从字符串 x 中的第 y 个位置开始长度为 z 的字符串

mysql> SELECT substr(concat(region,store_name),5) FROM location;
+-------------------------------------+
| substr(concat(region,store_name),5) |
+-------------------------------------+
| Boston                              |
| New York                            |
| Los Angeles                         |
| Houstion                            |
+-------------------------------------+
4 rows in set (0.00 sec)
---只显示Angele
mysql> SELECT substr(store_name,5,6) FROM location where store_name='Los Angeles';
+------------------------+
| substr(store_name,5,6) |
+------------------------+
| Angele                 |
+------------------------+
1 row in set (0.00 sec)

在这里插入图片描述

返回字符串 x 的长度

mysql> select store_name,length(store_name) from location;
+-------------+--------------------+
| store_name  | length(store_name) |
+-------------+--------------------+
| Boston      |                  6 |
| New York    |                  8 |
| Los Angeles |                 11 |
| Houstion    |                  8 |
+-------------+--------------------+
4 rows in set (0.00 sec)

在这里插入图片描述

将字符串 z 替代字符串 x 中的字符串 y

mysql> select replace(region,'st','stern') from location;
+------------------------------+
| replace(region,'st','stern') |
+------------------------------+
| Eastern                      |
| Eastern                      |
| Western                      |
| Western                      |
+------------------------------+
4 rows in set (0.00 sec)

在这里插入图片描述

三、mysql进阶查询（2）

3.1 GROUP BY

对GROUP BY后面的字段的查询结果进行汇总分组，通常是结合聚合函数一起使用的；

GROUP BY 有一个原则，凡是在 GROUP BY 后面出现的字段，必须在 SELECT 后面出现；

凡是在 SELECT 后面出现的、且未在聚合函数中出现的字段，必须出现在 GROUP BY 后面。

语法：SELECT "字段1", SUM("字段2") FROM "表名" GROUP BY "字段1";
---对store_name进行分组，并对sales降序排序
mysql> SELECT store_name, SUM(Sales) FROM store_info GROUP BY store_name ORDER BY SUM(Sales) desc;
+-------------+------------+
| store_name  | SUM(Sales) |
+-------------+------------+
| Los Angeles |       1800 |
| Boston      |        700 |
| Houston     |        250 |
+-------------+------------+
3 rows in set (0.00 sec)

在这里插入图片描述

3.2 HAVING

HAVING 语句的存在弥补了 WHERE 关键字不能与聚合函数联合使用的不足。

语法：SELECT "字段1", SUM("字段2") FROM "表格名" GROUP BY "字段1" HAVING (函数条件);
mysql> SELECT store_name, SUM(Sales) FROM store_info GROUP BY store_name having sum(sales)>1000;
+-------------+------------+
| store_name  | SUM(Sales) |
+-------------+------------+
| Los Angeles |       1800 |
+-------------+------------+

在这里插入图片描述

3.3 别名

语法：SELECT "表格別名"."字段1" [AS] "字段別名" FROM "表格名" [AS] "表格別名";
---字段设置别名
mysql> SELECT store_name, SUM(Sales) as total FROM store_info GROUP BY store_name having sum(sales)>1000;
+-------------+-------+
| store_name  | total |
+-------------+-------+
| Los Angeles |  1800 |
+-------------+-------+
1 row in set (0.00 sec)
---表别名
mysql> SELECT store_name, SUM(Sales) FROM store_info as a GROUP BY a.store_name ;
+-------------+------------+
| store_name  | SUM(Sales) |
+-------------+------------+
| Boston      |        700 |
| Houston     |        250 |
| Los Angeles |       1800 |
+-------------+------------+
3 rows in set (0.00 sec)

在这里插入图片描述

3.4 表的自我连接

---通过对分数排名
mysql> select * from student;
+------+----------+-------+
| id   | name     | score |
+------+----------+-------+
|    1 | zhangsan |    70 |
|    2 | lisi     |   100 |
|    3 | wangwu   |    80 |
|    4 | zhaoliu  |    90 |
+------+----------+-------+
mysql> select A.name,A.score,count(A.score) rank from student as A,student as B where A.score<=B.score group by A.name,A.score order by rank asc;
+----------+-------+------+
| name     | score | rank |
+----------+-------+------+
| lisi     |   100 |    1 |
| zhaoliu  |    90 |    2 |
| wangwu   |    80 |    3 |
| zhangsan |    70 |    4 |
+----------+-------+------+
4 rows in set (0.00 sec)

在这里插入图片描述

3.5 子查询

连接表格，在WHERE 子句或 HAVING 子句中插入另一个 SQL 语句
语法：SELECT "字段1" FROM "表格1" WHERE "字段2" [比较运算符] 			#外查询
(SELECT "字段1" FROM "表格2" WHERE "条件");						#内查询

#可以是符号的运算符，例如 =、>、<、>=、<= ；也可以是文字的运算符，例如 LIKE、IN、BETWEEN

---多表连接
mysql> select * from store_info A, location B where A.store_name=B.store_name;
+-------------+-------+------------+--------+-------------+
| Store_Name  | Sales | Date       | region | store_name  |
+-------------+-------+------------+--------+-------------+
| Boston      |   700 | 2020-12-08 | East   | Boston      |
| Los Angeles |  1500 | 2020-12-05 | West   | Los Angeles |
| Los Angeles |   300 | 2020-12-08 | West   | Los Angeles |
+-------------+-------+------------+--------+-------------+
3 rows in set (0.00 sec)

在这里插入图片描述

mysql> select * from store_info;
+-------------+-------+------------+
| Store_Name  | Sales | Date       |
+-------------+-------+------------+
| Los Angeles |  1500 | 2020-12-05 |
| Houston     |   250 | 2020-12-07 |
| Los Angeles |   300 | 2020-12-08 |
| Boston      |   700 | 2020-12-08 |
+-------------+-------+------------+
4 rows in set (0.01 sec)

mysql> select store_name from location where region='west';
+-------------+
| store_name  |
+-------------+
| Los Angeles |
| Houstion    |
+-------------+
2 rows in set (0.00 sec)

mysql> select sum(sales) from store_info where store_name in (select store_name from location where region='west');
+------------+
| sum(sales) |
+------------+
|       1800 |
+------------+
1 row in set (0.00 sec)

在这里插入图片描述

3.6 EXISTS

用来测试内查询有没有产生任何结果，类似布尔值是否为真

#如果有的话，系统就会执行外查询中的SQL语句。若是没有的话，那整个 SQL 语句就不会产生任何结果。
语法：SELECT "字段1" FROM "表格1" WHERE EXISTS (SELECT * FROM "表格2" WHERE "条件");
mysql> select sum(sales) from store_info where exists(select * from location where region = 'west');
+------------+
| sum(sales) |
+------------+
|       2750 |
+------------+
1 row in set (0.00 sec)

mysql> select sum(sales) from store_info where exists(select * from location where region = 'westeee');
+------------+
| sum(sales) |
+------------+
|       NULL |
+------------+
1 row in set (0.00 sec)

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3.7 连接查询

inner join(内连接):只返回两个表中联结字段相等的行
left join(左连接):返回包括左表中的所有记录和石表中联结字段相等的记录
right join(右连接):返回包括右表中的所有记录和左表中联结字段相等的记录

3.7.1 inner join(内连接)

 #连接两个表中字段记录相等的数据记录
 方法一:
 select * from location A inner join store_info B on A.store_name=B.store_name;
 方法二:
 select * from location A, store_info B where A.store_name=B.store_name;
 #连接两个表内字段数据记录相等的数据记录对region字段进行汇总分组并求和
select A.region region,sum(B.sales) sales from location A,store_info B where A.store_name = B.store_name group by region;

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3.7.2 left join(左连接)

mysql> select * from location A LEFT JOIN store_info B on A.store_name=B.store_name;
+--------+-------------+-------------+-------+------------+
| Region | Store_Name  | Store_Name  | Sales | Date       |
+--------+-------------+-------------+-------+------------+
| East   | Boston      | Boston      |   700 | 2020-12-08 |
| East   | New York    | NULL        |  NULL | NULL       |
| West   | Los Angeles | Los Angeles |  1500 | 2020-12-05 |
| West   | Los Angeles | Los Angeles |   300 | 2020-12-08 |
| West   | Houston     | Houston     |   250 | 2020-12-07 |
+--------+-------------+-------------+-------+------------+
5 rows in set (0.01 sec)

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3.7.3 right join(右连接)

mysql> select * from location A RIGHT JOIN store_info B on A.store_name=B.store_name;
+--------+-------------+-------------+-------+------------+
| Region | Store_Name  | Store_Name  | Sales | Date       |
+--------+-------------+-------------+-------+------------+
| West   | Los Angeles | Los Angeles |  1500 | 2020-12-05 |
| West   | Houston     | Houston     |   250 | 2020-12-07 |
| West   | Los Angeles | Los Angeles |   300 | 2020-12-08 |
| East   | Boston      | Boston      |   700 | 2020-12-08 |
| NULL   | NULL        | lll         |   758 | 2020-12-10 |
+--------+-------------+-------------+-------+------------+
5 rows in set (0.00 sec)

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mysql高级语句（一）（总有一个人的出现，让你的生活不再继续糟糕）

目录

前言

一、mysql进阶查询（1）

1.1 SELECT

1.2 DISTINCT

1.3 WHERE

1.4 AND OR

1.5 IN

1.6 BETWEEN

1.7 通配符与like

1.7 ORDER BY

二、函数

2.1 数学函数

2.2 聚合函数

2.3 字符串函数

三、mysql进阶查询（2）

3.1 GROUP BY

3.2 HAVING

3.3 别名

3.4 表的自我连接

3.5 子查询

3.6 EXISTS

3.7 连接查询

3.7.1 inner join(内连接)

3.7.2 left join(左连接)

3.7.3 right join(右连接)

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