fix

blog/mysq-advance/index.md

@@ -15,6 +15,8 @@
 
 [2. 索引](blog/mysq-advance/mysql-index.md)
 
+[3. SQL优化](blog/mysq-advance/sql-optimization.md)
+
 3. SQL 优化
 4. 视图/存储过程/触发器
 5. 锁
@@ -34,6 +36,4 @@ MySQL 运维篇
 - 3. [https://www.yuque.com/heychu/akbndd/zhuxqd](https://www.yuque.com/heychu/akbndd/zhuxqd)
 
 
-
-
-https://www.bilibili.com/video/BV1Kr4y1i7ru?p=89&spm_id_from=pageDriver
\ No newline at end of file
+https://www.bilibili.com/video/BV1Kr4y1i7ru?p=90&spm_id_from=pageDriver
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blog/mysq-advance/sql-optimization.md

+# SQL优化
+
+1. 插入数据
+2. 主键优化
+3. order by 优化
+4. group by 优化
+5. limit 优化
+6. count 优化
+7. update 优化
+
+## 1、插入数据
+
+逐条插入数据，性能较低，耗时较长
+
+```sql
+insert into tb_user (name, age) values ('Tom', 23);
+insert into tb_user (name, age) values ('Jack', 24);
+insert into tb_user (name, age) values ('Steve', 25);
+insert into tb_user (name, age) values ('Alice', 23);
+...
+```
+
+### 1.1、批量插入 
+
+将多条insert语句合并为一条insert语句，批量提交数据
+
+每次插入数据量建议：500-1000
+
+```sql
+insert into tb_user (name, age) values 
+('Tom', 23), ('Jack', 24), ('Steve', 25) ('Alice', 23);
+```
+
+### 1.2、手动事务提交
+
+减少事务开启关闭的次数
+
+```sql
+start transaction;
+insert into tb_user (name, age) values ('Tom', 23), ('Jack', 24);
+insert into tb_user (name, age) values ('Steve', 25) ('Alice', 23);
+commit;
+```
+
+### 1.3、主键顺序插入
+
+主键顺序插入的性能高于乱序插入
+
+```
+主键乱序插入 8 1 9 21 88 2 4 15 89 5 7 3
+主键顺序插入 1 2 3 4 5 6 7 8 9 10 88 99
+```
+
+### 1.4、大批量插入数据
+
+如果一次性需要插入大批量数据，使用insert语句插入性能较低
+
+可以使用MySQL数据库提供的`load` 指令进行数据插入
+
+
+```sql
+# 客户端连接服务端时，加上参数 `--local-infile`
+mysql --local-infile -uroot -p
+
+# 设置全局参数local_infile，开启从本地加载文件导入数据的关
+set global local_infile = 1;
+
+# 执行load指令将准备好的数据，加载到表结构中
+load data local infile '/root/data.csv' 
+into table `tb_user` 
+fields terminated by ',' 
+lines terminated by '\n';
+```
+
+示例
+
+利用Python脚本生成测试数据
+```python
+# Python >= 3.7.0
+# 安装依赖 pip install faker pandas
+from faker import Faker
+import pandas as pd
+
+# 简体中文：zh_CN
+faker = Faker(locale="zh_CN")
+# 指定随机种子，确保每次生成的数据都是一致的
+faker.seed(1)
+
+
+def get_row(index=0):
+    return {
+        'id': index + 1,
+        'username': faker.phone_number(),
+        'passowrd': faker.password(),
+        'name': faker.name(),
+        'birthday': faker.date_time().strftime("%Y-%m-%d"),
+        'sex': faker.random_int(0, 2),
+    }
+
+
+def main():
+    # 100万条数据
+    data = [ get_row(i) for i in range(100 * 10000)]
+    
+    # 将数据导出为csv文件, 不需要表头和序号
+    df = pd.DataFrame(data)
+    df.to_csv('./data_user.csv',
+              header=False,
+              index=False)
+
+
+if __name__ == '__main__':
+    main()
+
+```
+
+查看数据
+
+```bash
+# 查看要导入的测试数据
+$ wc -l data_user.csv 
+ 1000000 data_user.csv
+
+$ head data_user.csv
+1,13891417776,$h!PMHaS1#,魏玉珍,2021-12-20,1
+2,18883533740,BP3UqgUd&8,正红梅,2020-08-11,1
+3,18225851781,#$mMRcl98H,殳桂芝,1988-04-28,2
+4,13190682883,ywDqePXl&0,仰俊,2007-06-25,2
+5,13918401107,2!WP4H8it9,农琳,1993-05-13,1
+6,13334148396,3%8AqgmG!j,宗涛,2020-03-08,1
+7,13830411442,@&%9yI9r%e,荣建平,1977-02-08,2
+8,15948705964,y2VGFM0k!W,齐英,1981-07-19,0
+9,18983459845,I^5w1D^e)j,安凤英,2008-07-07,0
+10,15154981741,@!4A^CIt82,乜峰,2007-06-11,1
+
+```
+
+创建测试表
+
+```sql
+# 开启外部数据加载
+$ mysql --local-infile -uroot -p
+
+> select @@local_infile;
+
+> set global local_infile = 1;
+
+# 创建一个新的数据库和新的表来存放数据
+> show databases;
+
+> create database data_temp;
+
+> user data_temp;
+
+> create table tb_user(
+    id int primary key auto_increment,
+    username varchar(50) not null,
+    passowrd varchar(50) not null,
+    name varchar(20) not null,
+    birthday date default null,
+    sex tinyint default 0,
+    unique key uk_user_username (`username`)
+) engine=innodb default charset=utf8;
+```
+
+导入数据
+
+```sql
+> load data local infile '/data/data_user.csv' 
+into table `tb_user` 
+fields terminated by ',' 
+lines terminated by '\n';
+
+Query OK, 999830 rows affected, 170 warnings (17.68 sec)
+Records: 1000000  Deleted: 0  Skipped: 170  Warnings: 170
+```
+
+查看导入的数据
+
+```sql
+mysql> select * from tb_user limit 10;
++----+-------------+------------+-----------+------------+------+
+| id | username    | passowrd   | name      | birthday   | sex  |
++----+-------------+------------+-----------+------------+------+
+|  1 | 13891417776 | $h!PMHaS1# | 魏玉珍    | 2021-12-20 | 1    |
+|  2 | 18883533740 | BP3UqgUd&8 | 正红梅    | 2020-08-11 | 1    |
+|  3 | 18225851781 | #$mMRcl98H | 殳桂芝    | 1988-04-28 | 2    |
+|  4 | 13190682883 | ywDqePXl&0 | 仰俊      | 2007-06-25 | 2    |
+|  5 | 13918401107 | 2!WP4H8it9 | 农琳      | 1993-05-13 | 1    |
+|  6 | 13334148396 | 3%8AqgmG!j | 宗涛      | 2020-03-08 | 1    |
+|  7 | 13830411442 | @&%9yI9r%e | 荣建平    | 1977-02-08 | 2    |
+|  8 | 15948705964 | y2VGFM0k!W | 齐英      | 1981-07-19 | 0    |
+|  9 | 18983459845 | I^5w1D^e)j | 安凤英    | 2008-07-07 | 0    |
+| 10 | 15154981741 | @!4A^CIt82 | 乜峰      | 2007-06-11 | 1    |
++----+-------------+------------+-----------+------------+------+
+10 rows in set (0.00 sec)
+
+mysql> select count(*) from tb_user;
++----------+
+| count(*) |
++----------+
+|   999830 |
++----------+
+1 row in set (0.14 sec)
+
+```
+