From e22d21d3b799078670f907d12482242aaeac4c9a Mon Sep 17 00:00:00 2001
From: pengshiyu <1940607002@qq.com>
Date: Thu, 17 Mar 2022 22:45:46 +0800
Subject: [PATCH] fix

---
 blog/php-mysql/character.md |  69 ++++++++++++++++++++
 blog/php-mysql/index.md     |   8 ++-
 blog/php-mysql/sql-data.md  | 124 ++++++++++++++++++++++++++++++++++++
 blog/php-mysql/sql-table.md |   3 -
 4 files changed, 199 insertions(+), 5 deletions(-)
 create mode 100644 blog/php-mysql/character.md
 create mode 100644 blog/php-mysql/sql-data.md

diff --git a/blog/php-mysql/character.md b/blog/php-mysql/character.md
new file mode 100644
index 0000000..72f3501
--- /dev/null
+++ b/blog/php-mysql/character.md
@@ -0,0 +1,69 @@
+# 字符集 character
+
+- 字符 character 是各种文字和符号的总称
+- 字符编码 character code 是计算机针对各种符号，在计算机中的一种二进制存储代号
+- 字符集 character set 是多个字符的集合
+
+常见的字符集
+
+- ASCII 字符集
+- GB2312 字符集
+- Unicode 字符集
+
+# 设置客户端字符集
+
+```sql
+-- 设置客户端字符集编码
+set names gbk;
+
+-- 查看字符集编码设置
+show variables like 'character_set_%';
++--------------------------+------------+
+| Variable_name            | Value      |
++---------+-----------------------------+
+| character_set_client     | gbk        |
+| character_set_connection | gbk        |
+| character_set_database   | utf8mb4    |
+| character_set_filesystem | binary     |
+| character_set_results    | gbk        |
+| character_set_server     | utf8mb4    |
+| character_set_system     | utf8       |
+| character_sets_dir       | /usr/local/Cellar/mysql/8.0.16/share/mysql/charsets/ |
++--------------------------+------------+
+
+-- 插入中文字符
+insert into tb_teacher (name, age) values ('张三', 23);
+```
+
+MySQL 与 MySQLd 之间有三层
+
+- 客户端传入数据给服务端 client
+- 服务端返回数据给客户端 server
+- 客户端与服务端之间的连接 collection
+
+变量
+
+- character_set_client 客户端
+- character_set_connection 连接层
+- character_set_database 数据库
+- character_set_results 结果集
+
+修改变量
+
+```sql
+set 变量名 = 值;
+
+-- 修改单个变量
+set character_set_client = gbk;
+
+-- 设置字符集
+set names gbk;
+
+-- 等价于
+set character_set_client = gbk; // 让服务器识别客户端传过去的数据
+set character_set_connection = gbk; // 更好的帮助客户端与服务器端之间惊醒字符集转换
+set character_set_results = gbk; // 告诉客户端服务器返回的数据
+```
+
+
+https://www.bilibili.com/video/BV1Vx411g7uJ?p=15&spm_id_from=pageDriver
\ No newline at end of file
diff --git a/blog/php-mysql/index.md b/blog/php-mysql/index.md
index 34aa6cc..013893a 100644
--- a/blog/php-mysql/index.md
+++ b/blog/php-mysql/index.md
@@ -6,6 +6,10 @@
 
 [MySQL简介](blog/php-mysql/mysql-basic.md)
 
-[数据库基本操作](blog/php-mysql/sql-database.md)
+[数据库database 基本操作](blog/php-mysql/sql-database.md)
 
-[数据表基本操作](blog/php-mysql/sql-table.md)
+[数据表table 基本操作](blog/php-mysql/sql-table.md)
+
+[数据data 基本操作](blog/php-mysql/sql-data.md)
+
+[字符集character](blog/php-mysql/character.md)
diff --git a/blog/php-mysql/sql-data.md b/blog/php-mysql/sql-data.md
new file mode 100644
index 0000000..64c6359
--- /dev/null
+++ b/blog/php-mysql/sql-data.md
@@ -0,0 +1,124 @@
+# 数据操作
+
+## 插入操作
+
+```sql
+-- 方式一：插入指定字段数据（推荐使用）
+insert into 表名 [(字段列表)] values (对应列数据);
+
+-- 方式二：插入所有字段对应的数据
+insert into 表名 values (对应列数据);
+```
+
+示例
+
+```sql
+create table tb_teacher(
+ name varchar(10),
+ age int
+);
+
+-- 插入一条数据
+insert into tb_teacher (name, age) values ('Jack', 24);
+
+-- 字段名和值需要一一对应
+insert into tb_teacher (age, name) values (25, 'Tom');
+
+-- 可以只插入部分字段数据
+insert into tb_teacher (name) values ('Steve');
+
+-- 插入全部字段对应的数据,此时值列表需要对应表结构
+insert into tb_teacher values ('Jery', 23);
+```
+
+## 查询操作
+
+```sql
+-- 查询表中全部字段数据
+select * from 表名;
+
+-- 查询表中部分字段数据
+select 字段列表 from 表名;
+
+-- 简单条件查询数据
+select 字段列表/* from 表名 where 字段名 = 值;
+```
+
+示例
+
+```sql
+-- 查询所有数据
+select * from tb_teacher;
++-------+------+
+| name  | age  |
++-------+------+
+| Jack  |   24 |
+| Tom   |   25 |
+| Steve | NULL |
+| Jery  |   23 |
++-------+------+
+
+-- 指定字段
+select name from tb_teacher;
++-------+
+| name  |
++-------+
+| Jack  |
+| Tom   |
+| Steve |
+| Jery  |
++-------+
+
+-- 限制条件, 年龄==23
+select name from tb_teacher where age = 23;
++------+
+| name |
++------+
+| Jery |
++------+
+```
+
+## 删除操作
+
+```sql
+-- 如果没有条件，会删除所有数据
+delete from 表名 [where 条件];
+```
+
+```sql
+-- 删除年龄为23的数据
+delete from tb_teacher where age = 23;
+
+select * from tb_teacher;
++-------+------+
+| name  | age  |
++-------+------+
+| Jack  |   24 |
+| Tom   |   25 |
+| Steve | NULL |
++-------+------+
+```
+
+## 更新操作
+
+```sql
+-- 如果没有where条件，将会更新表中所有的值
+update 表名 set 字段名 = 新值 [where 条件];
+```
+
+示例
+
+```sql
+-- 更新Tom的年龄为26
+update tb_teacher set age = 26 where name = 'Tom';
+
+select * from tb_teacher;
++-------+------+
+| name  | age  |
++-------+------+
+| Jack  |   24 |
+| Tom   |   26 |
+| Steve | NULL |
++-------+------+
+```
+
diff --git a/blog/php-mysql/sql-table.md b/blog/php-mysql/sql-table.md
index 4684e92..def1aca 100644
--- a/blog/php-mysql/sql-table.md
+++ b/blog/php-mysql/sql-table.md
@@ -305,6 +305,3 @@ mysql> show tables;
 | t_author             |
 +----------------------+
 ```
-
-
-https://www.bilibili.com/video/BV1Vx411g7uJ?p=11&spm_id_from=pageDriver
\ No newline at end of file
-- 
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