【MYSQL】MYSQL学习的一大重点：MYSQL库的操作

艾莉丝努力练剑2026-03-12 8:31

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文章目录

  • [0 ~> 实际场景：创建和删除数据库](#0 ~> 实际场景：创建和删除数据库)
    • [0.1 创建方式1](#0.1 创建方式1)
    • [0.2 创建方式2](#0.2 创建方式2)
    • [0.3 创建方式3](#0.3 创建方式3)
  • [1 ~> 数据库的编码集](#1 ~> 数据库的编码集)
    • [1.1 目前整个数据库支持的字符集](#1.1 目前整个数据库支持的字符集)
    • [1.2 目前整个数据库支持的字符集](#1.2 目前整个数据库支持的字符集)
    • [1.3 UTF-8需要设置配置文件](#1.3 UTF-8需要设置配置文件)
    • [1.4 MySQL 中与字符集排序规则（collation）相关的系统变量](#1.4 MySQL 中与字符集排序规则（collation）相关的系统变量)
    • [1.5 字符集和校验集是具有匹配关系的](#1.5 字符集和校验集是具有匹配关系的)
      • [1.5.1 整个数据库支持的字符集](#1.5.1 整个数据库支持的字符集)
      • [1.5.2 整个数据库支持的校验集](#1.5.2 整个数据库支持的校验集)
  • [2 ~> 过渡](#2 ~> 过渡)
  • [3 ~> 创建数据库（附带案例）](#3 ~> 创建数据库（附带案例）)
    • [3.1 创建数据库：语法 + 理解](#3.1 创建数据库：语法 + 理解)
    • [3.2 创建数据库的案例](#3.2 创建数据库的案例)
      • [3.2.1 创建名为db1的数据库](#3.2.1 创建名为db1的数据库)
      • [3.2.2 创建一个使用utf8字符集的db2数据库](#3.2.2 创建一个使用utf8字符集的db2数据库)
      • [3.2.3 创建一个使用utf字符集，并带校对规则的 db3 数据库。](#3.2.3 创建一个使用utf字符集，并带校对规则的 db3 数据库。)
  • [4 ~> 字符集和校验规则](#4 ~> 字符集和校验规则)
    • [4.1 查看系统默认字符集以及校验规则](#4.1 查看系统默认字符集以及校验规则)
    • [4.2 查看数据库支持的字符集](#4.2 查看数据库支持的字符集)
    • [4.3 查看数据库支持的字符集校验规则](#4.3 查看数据库支持的字符集校验规则)
    • [4.4 校验规则对数据库的影响](#4.4 校验规则对数据库的影响)
    • [4.4.1 不区分大小写](#4.4.1 不区分大小写)
      • [4.4.2 区分大小写](#4.4.2 区分大小写)
      • [4.4.3 进行查询](#4.4.3 进行查询)
        • [4.4.3.1 不区分大小写的查询以及结果](#4.4.3.1 不区分大小写的查询以及结果)
        • [4.4.3.2 区分大小写的查询以及结果](#4.4.3.2 区分大小写的查询以及结果)
      • [4.4.4 结果排序](#4.4.4 结果排序)
        • [4.4.4.1 不区分大小写排序以及结果](#4.4.4.1 不区分大小写排序以及结果)
        • [4.4.4.2 区分大小写排序以及结果](#4.4.4.2 区分大小写排序以及结果)
  • [5 ~> 操纵数据库](#5 ~> 操纵数据库)
    • [5.1 查看数据库](#5.1 查看数据库)
    • [5.2 显示创建语句](#5.2 显示创建语句)
    • [5.2 修改数据库](#5.2 修改数据库)
    • [5.3 数据库删除](#5.3 数据库删除)
    • [5.4 备份和恢复：放在最后](#5.4 备份和恢复：放在最后)
      • [5.4.1 备份](#5.4.1 备份)
      • [5.4.2 还原](#5.4.2 还原)
      • [5.4.3 注意事项](#5.4.3 注意事项)
    • [5.5 查看连接情况](#5.5 查看连接情况)
  • [6 ~> MYSQL操作库部分的思维导图](#6 ~> MYSQL操作库部分的思维导图)
  • 结尾

0 ~> 实际场景：创建和删除数据库

0.1 创建方式1

bash 复制代码 
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| helloworld         |
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
6 rows in set (0.00 sec)

mysql> create database database1;
Query OK, 1 row affected (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| database1          |
| helloworld         |
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

mysql> drop database database1;
Query OK, 0 rows affected (0.01 sec)

mysql> 
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| helloworld         |
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
6 rows in set (0.00 sec)

0.2 创建方式2

bash 复制代码 
mysql> create database if not exists database1;
Query OK, 1 row affected (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| database1          |
| helloworld         |
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

mysql> drop database database1;
Query OK, 0 rows affected (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| helloworld         |
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
6 rows in set (0.00 sec)

0.3 创建方式3

下面这种创建方式叫做：既指明了 数据库的编码又指明了校验码------

bash 复制代码 
mysql> create database d4 charset=utf8 collate utf8_general_ci;
Query OK, 1 row affected, 2 warnings (0.01 sec)

1 ~> 数据库的编码集

1.1 目前整个数据库支持的字符集

默认支持的字符集是UTF-8，我们可以验证一下------

bash 复制代码 
mysql> show variables like 'character_set_database';
+------------------------+---------+
| Variable_name          | Value   |
+------------------------+---------+
| character_set_database | utf8mb4 |
+------------------------+---------+
1 row in set (0.01 sec)

1.2 目前整个数据库支持的字符集

它还有个校验集------

bash 复制代码 
mysql> show variables like 'collation_database';
+--------------------+--------------------+
| Variable_name      | Value              |
+--------------------+--------------------+
| collation_database | utf8mb4_0900_ai_ci |
+--------------------+--------------------+
1 row in set (0.00 sec)

1.3 UTF-8需要设置配置文件

我们发现上面的编码规则并不是UTF-8，为什么呢？

其实是因为我们没有改对应的配置文件 ，如果要显示为UTF-8需要我们修改配置文件。

1.4 MySQL 中与字符集排序规则（collation）相关的系统变量

我们可以查看MySQL 中与字符集排序规则（collation）相关的系统变量：

bash 复制代码 
mysql> show variables like 'collation_%';
+----------------------+--------------------+
| Variable_name        | Value              |
+----------------------+--------------------+
| collation_connection | utf8mb4_0900_ai_ci |
| collation_database   | utf8mb4_0900_ai_ci |
| collation_server     | utf8mb4_0900_ai_ci |
+----------------------+--------------------+
3 rows in set (0.00 sec)

如下图所示：

这里我们得到的三行分别代表三个不同级别的排序规则设置：

1.5 字符集和校验集是具有匹配关系的

字符集和校验集是具有匹配关系的，从下面两张我们可以查到的图就可以很明显的看出------

  • 我们熟悉的字符集主要是gbk和utf-8，我们通过这两个字符集就可以理解上面那句话：即【字符集和校验集是具有匹配关系的】。

1.5.1 整个数据库支持的字符集

我们可以查看目前整个数据库支持的字符集：

bash 复制代码 
mysql> show charset;
+----------+---------------------------------+---------------------+--------+
| Charset  | Description                     | Default collation   | Maxlen |
+----------+---------------------------------+---------------------+--------+
| armscii8 | ARMSCII-8 Armenian              | armscii8_general_ci |      1 |
| ascii    | US ASCII                        | ascii_general_ci    |      1 |
| big5     | Big5 Traditional Chinese        | big5_chinese_ci     |      2 |
| binary   | Binary pseudo charset           | binary              |      1 |
| cp1250   | Windows Central European        | cp1250_general_ci   |      1 |
| cp1251   | Windows Cyrillic                | cp1251_general_ci   |      1 |
| cp1256   | Windows Arabic                  | cp1256_general_ci   |      1 |
| cp1257   | Windows Baltic                  | cp1257_general_ci   |      1 |
| cp850    | DOS West European               | cp850_general_ci    |      1 |
| cp852    | DOS Central European            | cp852_general_ci    |      1 |
| cp866    | DOS Russian                     | cp866_general_ci    |      1 |
| cp932    | SJIS for Windows Japanese       | cp932_japanese_ci   |      2 |
| dec8     | DEC West European               | dec8_swedish_ci     |      1 |
| eucjpms  | UJIS for Windows Japanese       | eucjpms_japanese_ci |      3 |
| euckr    | EUC-KR Korean                   | euckr_korean_ci     |      2 |
| gb18030  | China National Standard GB18030 | gb18030_chinese_ci  |      4 |
| gb2312   | GB2312 Simplified Chinese       | gb2312_chinese_ci   |      2 |
| gbk      | GBK Simplified Chinese          | gbk_chinese_ci      |      2 |
| geostd8  | GEOSTD8 Georgian                | geostd8_general_ci  |      1 |
| greek    | ISO 8859-7 Greek                | greek_general_ci    |      1 |
| hebrew   | ISO 8859-8 Hebrew               | hebrew_general_ci   |      1 |
| hp8      | HP West European                | hp8_english_ci      |      1 |
| keybcs2  | DOS Kamenicky Czech-Slovak      | keybcs2_general_ci  |      1 |
| koi8r    | KOI8-R Relcom Russian           | koi8r_general_ci    |      1 |
| koi8u    | KOI8-U Ukrainian                | koi8u_general_ci    |      1 |
| latin1   | cp1252 West European            | latin1_swedish_ci   |      1 |
| latin2   | ISO 8859-2 Central European     | latin2_general_ci   |      1 |
| latin5   | ISO 8859-9 Turkish              | latin5_turkish_ci   |      1 |
| latin7   | ISO 8859-13 Baltic              | latin7_general_ci   |      1 |
| macce    | Mac Central European            | macce_general_ci    |      1 |
| macroman | Mac West European               | macroman_general_ci |      1 |
| sjis     | Shift-JIS Japanese              | sjis_japanese_ci    |      2 |
| swe7     | 7bit Swedish                    | swe7_swedish_ci     |      1 |
| tis620   | TIS620 Thai                     | tis620_thai_ci      |      1 |
| ucs2     | UCS-2 Unicode                   | ucs2_general_ci     |      2 |
| ujis     | EUC-JP Japanese                 | ujis_japanese_ci    |      3 |
| utf16    | UTF-16 Unicode                  | utf16_general_ci    |      4 |
| utf16le  | UTF-16LE Unicode                | utf16le_general_ci  |      4 |
| utf32    | UTF-32 Unicode                  | utf32_general_ci    |      4 |
| utf8mb3  | UTF-8 Unicode                   | utf8mb3_general_ci  |      3 |
| utf8mb4  | UTF-8 Unicode                   | utf8mb4_0900_ai_ci  |      4 |
+----------+---------------------------------+---------------------+--------+
41 rows in set (0.00 sec)

1.5.2 整个数据库支持的校验集

我们可以查看目前整个数据库支持的校验集：

bash 复制代码 
mysql> show collation;
+-----------------------------+----------+-----+---------+----------+---------+---------------+
| Collation                   | Charset  | Id  | Default | Compiled | Sortlen | Pad_attribute |
+-----------------------------+----------+-----+---------+----------+---------+---------------+
| armscii8_bin                | armscii8 |  64 |         | Yes      |       1 | PAD SPACE     |
| armscii8_general_ci         | armscii8 |  32 | Yes     | Yes      |       1 | PAD SPACE     |
| ascii_bin                   | ascii    |  65 |         | Yes      |       1 | PAD SPACE     |
| ascii_general_ci            | ascii    |  11 | Yes     | Yes      |       1 | PAD SPACE     |
| big5_bin                    | big5     |  84 |         | Yes      |       1 | PAD SPACE     |
| big5_chinese_ci             | big5     |   1 | Yes     | Yes      |       1 | PAD SPACE     |
| binary                      | binary   |  63 | Yes     | Yes      |       1 | NO PAD        |
| cp1250_bin                  | cp1250   |  66 |         | Yes      |       1 | PAD SPACE     |
| cp1250_croatian_ci          | cp1250   |  44 |         | Yes      |       1 | PAD SPACE     |
| cp1250_czech_cs             | cp1250   |  34 |         | Yes      |       2 | PAD SPACE     |
| cp1250_general_ci           | cp1250   |  26 | Yes     | Yes      |       1 | PAD SPACE     |
| cp1250_polish_ci            | cp1250   |  99 |         | Yes      |       1 | PAD SPACE     |
| cp1251_bin                  | cp1251   |  50 |         | Yes      |       1 | PAD SPACE     |
| cp1251_bulgarian_ci         | cp1251   |  14 |         | Yes      |       1 | PAD SPACE     |
| cp1251_general_ci           | cp1251   |  51 | Yes     | Yes      |       1 | PAD SPACE     |
| cp1251_general_cs           | cp1251   |  52 |         | Yes      |       1 | PAD SPACE     |
| cp1251_ukrainian_ci         | cp1251   |  23 |         | Yes      |       1 | PAD SPACE     |
| cp1256_bin                  | cp1256   |  67 |         | Yes      |       1 | PAD SPACE     |
| cp1256_general_ci           | cp1256   |  57 | Yes     | Yes      |       1 | PAD SPACE     |
| cp1257_bin                  | cp1257   |  58 |         | Yes      |       1 | PAD SPACE     |
| cp1257_general_ci           | cp1257   |  59 | Yes     | Yes      |       1 | PAD SPACE     |
| cp1257_lithuanian_ci        | cp1257   |  29 |         | Yes      |       1 | PAD SPACE     |
| cp850_bin                   | cp850    |  80 |         | Yes      |       1 | PAD SPACE     |
| cp850_general_ci            | cp850    |   4 | Yes     | Yes      |       1 | PAD SPACE     |
| cp852_bin                   | cp852    |  81 |         | Yes      |       1 | PAD SPACE     |
| cp852_general_ci            | cp852    |  40 | Yes     | Yes      |       1 | PAD SPACE     |
| cp866_bin                   | cp866    |  68 |         | Yes      |       1 | PAD SPACE     |
| cp866_general_ci            | cp866    |  36 | Yes     | Yes      |       1 | PAD SPACE     |
| cp932_bin                   | cp932    |  96 |         | Yes      |       1 | PAD SPACE     |
| cp932_japanese_ci           | cp932    |  95 | Yes     | Yes      |       1 | PAD SPACE     |
| dec8_bin                    | dec8     |  69 |         | Yes      |       1 | PAD SPACE     |
| dec8_swedish_ci             | dec8     |   3 | Yes     | Yes      |       1 | PAD SPACE     |
| eucjpms_bin                 | eucjpms  |  98 |         | Yes      |       1 | PAD SPACE     |
| eucjpms_japanese_ci         | eucjpms  |  97 | Yes     | Yes      |       1 | PAD SPACE     |
| euckr_bin                   | euckr    |  85 |         | Yes      |       1 | PAD SPACE     |
| euckr_korean_ci             | euckr    |  19 | Yes     | Yes      |       1 | PAD SPACE     |
| gb18030_bin                 | gb18030  | 249 |         | Yes      |       1 | PAD SPACE     |
| gb18030_chinese_ci          | gb18030  | 248 | Yes     | Yes      |       2 | PAD SPACE     |
| gb18030_unicode_520_ci      | gb18030  | 250 |         | Yes      |       8 | PAD SPACE     |
| gb2312_bin                  | gb2312   |  86 |         | Yes      |       1 | PAD SPACE     |
| gb2312_chinese_ci           | gb2312   |  24 | Yes     | Yes      |       1 | PAD SPACE     |
| gbk_bin                     | gbk      |  87 |         | Yes      |       1 | PAD SPACE     |
| gbk_chinese_ci              | gbk      |  28 | Yes     | Yes      |       1 | PAD SPACE     |
| geostd8_bin                 | geostd8  |  93 |         | Yes      |       1 | PAD SPACE     |
| geostd8_general_ci          | geostd8  |  92 | Yes     | Yes      |       1 | PAD SPACE     |
| greek_bin                   | greek    |  70 |         | Yes      |       1 | PAD SPACE     |
| greek_general_ci            | greek    |  25 | Yes     | Yes      |       1 | PAD SPACE     |
| hebrew_bin                  | hebrew   |  71 |         | Yes      |       1 | PAD SPACE     |
| hebrew_general_ci           | hebrew   |  16 | Yes     | Yes      |       1 | PAD SPACE     |
| hp8_bin                     | hp8      |  72 |         | Yes      |       1 | PAD SPACE     |
| hp8_english_ci              | hp8      |   6 | Yes     | Yes      |       1 | PAD SPACE     |
| keybcs2_bin                 | keybcs2  |  73 |         | Yes      |       1 | PAD SPACE     |
| keybcs2_general_ci          | keybcs2  |  37 | Yes     | Yes      |       1 | PAD SPACE     |
| koi8r_bin                   | koi8r    |  74 |         | Yes      |       1 | PAD SPACE     |
| koi8r_general_ci            | koi8r    |   7 | Yes     | Yes      |       1 | PAD SPACE     |
| koi8u_bin                   | koi8u    |  75 |         | Yes      |       1 | PAD SPACE     |
| koi8u_general_ci            | koi8u    |  22 | Yes     | Yes      |       1 | PAD SPACE     |
| latin1_bin                  | latin1   |  47 |         | Yes      |       1 | PAD SPACE     |
| latin1_danish_ci            | latin1   |  15 |         | Yes      |       1 | PAD SPACE     |
| latin1_general_ci           | latin1   |  48 |         | Yes      |       1 | PAD SPACE     |
| latin1_general_cs           | latin1   |  49 |         | Yes      |       1 | PAD SPACE     |
| latin1_german1_ci           | latin1   |   5 |         | Yes      |       1 | PAD SPACE     |
| latin1_german2_ci           | latin1   |  31 |         | Yes      |       2 | PAD SPACE     |
| latin1_spanish_ci           | latin1   |  94 |         | Yes      |       1 | PAD SPACE     |
| latin1_swedish_ci           | latin1   |   8 | Yes     | Yes      |       1 | PAD SPACE     |
| latin2_bin                  | latin2   |  77 |         | Yes      |       1 | PAD SPACE     |
| latin2_croatian_ci          | latin2   |  27 |         | Yes      |       1 | PAD SPACE     |
| latin2_czech_cs             | latin2   |   2 |         | Yes      |       4 | PAD SPACE     |
| latin2_general_ci           | latin2   |   9 | Yes     | Yes      |       1 | PAD SPACE     |
| latin2_hungarian_ci         | latin2   |  21 |         | Yes      |       1 | PAD SPACE     |
| latin5_bin                  | latin5   |  78 |         | Yes      |       1 | PAD SPACE     |
| latin5_turkish_ci           | latin5   |  30 | Yes     | Yes      |       1 | PAD SPACE     |
| latin7_bin                  | latin7   |  79 |         | Yes      |       1 | PAD SPACE     |
| latin7_estonian_cs          | latin7   |  20 |         | Yes      |       1 | PAD SPACE     |
| latin7_general_ci           | latin7   |  41 | Yes     | Yes      |       1 | PAD SPACE     |
| latin7_general_cs           | latin7   |  42 |         | Yes      |       1 | PAD SPACE     |
| macce_bin                   | macce    |  43 |         | Yes      |       1 | PAD SPACE     |
| macce_general_ci            | macce    |  38 | Yes     | Yes      |       1 | PAD SPACE     |
| macroman_bin                | macroman |  53 |         | Yes      |       1 | PAD SPACE     |
| macroman_general_ci         | macroman |  39 | Yes     | Yes      |       1 | PAD SPACE     |
| sjis_bin                    | sjis     |  88 |         | Yes      |       1 | PAD SPACE     |
| sjis_japanese_ci            | sjis     |  13 | Yes     | Yes      |       1 | PAD SPACE     |
| swe7_bin                    | swe7     |  82 |         | Yes      |       1 | PAD SPACE     |
| swe7_swedish_ci             | swe7     |  10 | Yes     | Yes      |       1 | PAD SPACE     |
| tis620_bin                  | tis620   |  89 |         | Yes      |       1 | PAD SPACE     |
| tis620_thai_ci              | tis620   |  18 | Yes     | Yes      |       4 | PAD SPACE     |
| ucs2_bin                    | ucs2     |  90 |         | Yes      |       1 | PAD SPACE     |
| ucs2_croatian_ci            | ucs2     | 149 |         | Yes      |       8 | PAD SPACE     |
| ucs2_czech_ci               | ucs2     | 138 |         | Yes      |       8 | PAD SPACE     |
| ucs2_danish_ci              | ucs2     | 139 |         | Yes      |       8 | PAD SPACE     |
| ucs2_esperanto_ci           | ucs2     | 145 |         | Yes      |       8 | PAD SPACE     |
| ucs2_estonian_ci            | ucs2     | 134 |         | Yes      |       8 | PAD SPACE     |
| ucs2_general_ci             | ucs2     |  35 | Yes     | Yes      |       1 | PAD SPACE     |
| ucs2_general_mysql500_ci    | ucs2     | 159 |         | Yes      |       1 | PAD SPACE     |
| ucs2_german2_ci             | ucs2     | 148 |         | Yes      |       8 | PAD SPACE     |
| ucs2_hungarian_ci           | ucs2     | 146 |         | Yes      |       8 | PAD SPACE     |
| ucs2_icelandic_ci           | ucs2     | 129 |         | Yes      |       8 | PAD SPACE     |
| ucs2_latvian_ci             | ucs2     | 130 |         | Yes      |       8 | PAD SPACE     |
| ucs2_lithuanian_ci          | ucs2     | 140 |         | Yes      |       8 | PAD SPACE     |
| ucs2_persian_ci             | ucs2     | 144 |         | Yes      |       8 | PAD SPACE     |
| ucs2_polish_ci              | ucs2     | 133 |         | Yes      |       8 | PAD SPACE     |
| ucs2_romanian_ci            | ucs2     | 131 |         | Yes      |       8 | PAD SPACE     |
| ucs2_roman_ci               | ucs2     | 143 |         | Yes      |       8 | PAD SPACE     |
| ucs2_sinhala_ci             | ucs2     | 147 |         | Yes      |       8 | PAD SPACE     |
| ucs2_slovak_ci              | ucs2     | 141 |         | Yes      |       8 | PAD SPACE     |
| ucs2_slovenian_ci           | ucs2     | 132 |         | Yes      |       8 | PAD SPACE     |
| ucs2_spanish2_ci            | ucs2     | 142 |         | Yes      |       8 | PAD SPACE     |
| ucs2_spanish_ci             | ucs2     | 135 |         | Yes      |       8 | PAD SPACE     |
| ucs2_swedish_ci             | ucs2     | 136 |         | Yes      |       8 | PAD SPACE     |
| ucs2_turkish_ci             | ucs2     | 137 |         | Yes      |       8 | PAD SPACE     |
| ucs2_unicode_520_ci         | ucs2     | 150 |         | Yes      |       8 | PAD SPACE     |
| ucs2_unicode_ci             | ucs2     | 128 |         | Yes      |       8 | PAD SPACE     |
| ucs2_vietnamese_ci          | ucs2     | 151 |         | Yes      |       8 | PAD SPACE     |
| ujis_bin                    | ujis     |  91 |         | Yes      |       1 | PAD SPACE     |
| ujis_japanese_ci            | ujis     |  12 | Yes     | Yes      |       1 | PAD SPACE     |
| utf16le_bin                 | utf16le  |  62 |         | Yes      |       1 | PAD SPACE     |
| utf16le_general_ci          | utf16le  |  56 | Yes     | Yes      |       1 | PAD SPACE     |
| utf16_bin                   | utf16    |  55 |         | Yes      |       1 | PAD SPACE     |
| utf16_croatian_ci           | utf16    | 122 |         | Yes      |       8 | PAD SPACE     |
| utf16_czech_ci              | utf16    | 111 |         | Yes      |       8 | PAD SPACE     |
| utf16_danish_ci             | utf16    | 112 |         | Yes      |       8 | PAD SPACE     |
| utf16_esperanto_ci          | utf16    | 118 |         | Yes      |       8 | PAD SPACE     |
| utf16_estonian_ci           | utf16    | 107 |         | Yes      |       8 | PAD SPACE     |
| utf16_general_ci            | utf16    |  54 | Yes     | Yes      |       1 | PAD SPACE     |
| utf16_german2_ci            | utf16    | 121 |         | Yes      |       8 | PAD SPACE     |
| utf16_hungarian_ci          | utf16    | 119 |         | Yes      |       8 | PAD SPACE     |
| utf16_icelandic_ci          | utf16    | 102 |         | Yes      |       8 | PAD SPACE     |
| utf16_latvian_ci            | utf16    | 103 |         | Yes      |       8 | PAD SPACE     |
| utf16_lithuanian_ci         | utf16    | 113 |         | Yes      |       8 | PAD SPACE     |
| utf16_persian_ci            | utf16    | 117 |         | Yes      |       8 | PAD SPACE     |
| utf16_polish_ci             | utf16    | 106 |         | Yes      |       8 | PAD SPACE     |
| utf16_romanian_ci           | utf16    | 104 |         | Yes      |       8 | PAD SPACE     |
| utf16_roman_ci              | utf16    | 116 |         | Yes      |       8 | PAD SPACE     |
| utf16_sinhala_ci            | utf16    | 120 |         | Yes      |       8 | PAD SPACE     |
| utf16_slovak_ci             | utf16    | 114 |         | Yes      |       8 | PAD SPACE     |
| utf16_slovenian_ci          | utf16    | 105 |         | Yes      |       8 | PAD SPACE     |
| utf16_spanish2_ci           | utf16    | 115 |         | Yes      |       8 | PAD SPACE     |
| utf16_spanish_ci            | utf16    | 108 |         | Yes      |       8 | PAD SPACE     |
| utf16_swedish_ci            | utf16    | 109 |         | Yes      |       8 | PAD SPACE     |
| utf16_turkish_ci            | utf16    | 110 |         | Yes      |       8 | PAD SPACE     |
| utf16_unicode_520_ci        | utf16    | 123 |         | Yes      |       8 | PAD SPACE     |
| utf16_unicode_ci            | utf16    | 101 |         | Yes      |       8 | PAD SPACE     |
| utf16_vietnamese_ci         | utf16    | 124 |         | Yes      |       8 | PAD SPACE     |
| utf32_bin                   | utf32    |  61 |         | Yes      |       1 | PAD SPACE     |
| utf32_croatian_ci           | utf32    | 181 |         | Yes      |       8 | PAD SPACE     |
| utf32_czech_ci              | utf32    | 170 |         | Yes      |       8 | PAD SPACE     |
| utf32_danish_ci             | utf32    | 171 |         | Yes      |       8 | PAD SPACE     |
| utf32_esperanto_ci          | utf32    | 177 |         | Yes      |       8 | PAD SPACE     |
| utf32_estonian_ci           | utf32    | 166 |         | Yes      |       8 | PAD SPACE     |
| utf32_general_ci            | utf32    |  60 | Yes     | Yes      |       1 | PAD SPACE     |
| utf32_german2_ci            | utf32    | 180 |         | Yes      |       8 | PAD SPACE     |
| utf32_hungarian_ci          | utf32    | 178 |         | Yes      |       8 | PAD SPACE     |
| utf32_icelandic_ci          | utf32    | 161 |         | Yes      |       8 | PAD SPACE     |
| utf32_latvian_ci            | utf32    | 162 |         | Yes      |       8 | PAD SPACE     |
| utf32_lithuanian_ci         | utf32    | 172 |         | Yes      |       8 | PAD SPACE     |
| utf32_persian_ci            | utf32    | 176 |         | Yes      |       8 | PAD SPACE     |
| utf32_polish_ci             | utf32    | 165 |         | Yes      |       8 | PAD SPACE     |
| utf32_romanian_ci           | utf32    | 163 |         | Yes      |       8 | PAD SPACE     |
| utf32_roman_ci              | utf32    | 175 |         | Yes      |       8 | PAD SPACE     |
| utf32_sinhala_ci            | utf32    | 179 |         | Yes      |       8 | PAD SPACE     |
| utf32_slovak_ci             | utf32    | 173 |         | Yes      |       8 | PAD SPACE     |
| utf32_slovenian_ci          | utf32    | 164 |         | Yes      |       8 | PAD SPACE     |
| utf32_spanish2_ci           | utf32    | 174 |         | Yes      |       8 | PAD SPACE     |
| utf32_spanish_ci            | utf32    | 167 |         | Yes      |       8 | PAD SPACE     |
| utf32_swedish_ci            | utf32    | 168 |         | Yes      |       8 | PAD SPACE     |
| utf32_turkish_ci            | utf32    | 169 |         | Yes      |       8 | PAD SPACE     |
| utf32_unicode_520_ci        | utf32    | 182 |         | Yes      |       8 | PAD SPACE     |
| utf32_unicode_ci            | utf32    | 160 |         | Yes      |       8 | PAD SPACE     |
| utf32_vietnamese_ci         | utf32    | 183 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_bin                 | utf8mb3  |  83 |         | Yes      |       1 | PAD SPACE     |
| utf8mb3_croatian_ci         | utf8mb3  | 213 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_czech_ci            | utf8mb3  | 202 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_danish_ci           | utf8mb3  | 203 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_esperanto_ci        | utf8mb3  | 209 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_estonian_ci         | utf8mb3  | 198 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_general_ci          | utf8mb3  |  33 | Yes     | Yes      |       1 | PAD SPACE     |
| utf8mb3_general_mysql500_ci | utf8mb3  | 223 |         | Yes      |       1 | PAD SPACE     |
| utf8mb3_german2_ci          | utf8mb3  | 212 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_hungarian_ci        | utf8mb3  | 210 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_icelandic_ci        | utf8mb3  | 193 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_latvian_ci          | utf8mb3  | 194 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_lithuanian_ci       | utf8mb3  | 204 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_persian_ci          | utf8mb3  | 208 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_polish_ci           | utf8mb3  | 197 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_romanian_ci         | utf8mb3  | 195 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_roman_ci            | utf8mb3  | 207 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_sinhala_ci          | utf8mb3  | 211 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_slovak_ci           | utf8mb3  | 205 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_slovenian_ci        | utf8mb3  | 196 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_spanish2_ci         | utf8mb3  | 206 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_spanish_ci          | utf8mb3  | 199 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_swedish_ci          | utf8mb3  | 200 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_tolower_ci          | utf8mb3  |  76 |         | Yes      |       1 | PAD SPACE     |
| utf8mb3_turkish_ci          | utf8mb3  | 201 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_unicode_520_ci      | utf8mb3  | 214 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_unicode_ci          | utf8mb3  | 192 |         | Yes      |       8 | PAD SPACE     |
| utf8mb3_vietnamese_ci       | utf8mb3  | 215 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_0900_ai_ci          | utf8mb4  | 255 | Yes     | Yes      |       0 | NO PAD        |
| utf8mb4_0900_as_ci          | utf8mb4  | 305 |         | Yes      |       0 | NO PAD        |
| utf8mb4_0900_as_cs          | utf8mb4  | 278 |         | Yes      |       0 | NO PAD        |
| utf8mb4_0900_bin            | utf8mb4  | 309 |         | Yes      |       1 | NO PAD        |
| utf8mb4_bg_0900_ai_ci       | utf8mb4  | 318 |         | Yes      |       0 | NO PAD        |
| utf8mb4_bg_0900_as_cs       | utf8mb4  | 319 |         | Yes      |       0 | NO PAD        |
| utf8mb4_bin                 | utf8mb4  |  46 |         | Yes      |       1 | PAD SPACE     |
| utf8mb4_bs_0900_ai_ci       | utf8mb4  | 316 |         | Yes      |       0 | NO PAD        |
| utf8mb4_bs_0900_as_cs       | utf8mb4  | 317 |         | Yes      |       0 | NO PAD        |
| utf8mb4_croatian_ci         | utf8mb4  | 245 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_cs_0900_ai_ci       | utf8mb4  | 266 |         | Yes      |       0 | NO PAD        |
| utf8mb4_cs_0900_as_cs       | utf8mb4  | 289 |         | Yes      |       0 | NO PAD        |
| utf8mb4_czech_ci            | utf8mb4  | 234 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_danish_ci           | utf8mb4  | 235 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_da_0900_ai_ci       | utf8mb4  | 267 |         | Yes      |       0 | NO PAD        |
| utf8mb4_da_0900_as_cs       | utf8mb4  | 290 |         | Yes      |       0 | NO PAD        |
| utf8mb4_de_pb_0900_ai_ci    | utf8mb4  | 256 |         | Yes      |       0 | NO PAD        |
| utf8mb4_de_pb_0900_as_cs    | utf8mb4  | 279 |         | Yes      |       0 | NO PAD        |
| utf8mb4_eo_0900_ai_ci       | utf8mb4  | 273 |         | Yes      |       0 | NO PAD        |
| utf8mb4_eo_0900_as_cs       | utf8mb4  | 296 |         | Yes      |       0 | NO PAD        |
| utf8mb4_esperanto_ci        | utf8mb4  | 241 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_estonian_ci         | utf8mb4  | 230 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_es_0900_ai_ci       | utf8mb4  | 263 |         | Yes      |       0 | NO PAD        |
| utf8mb4_es_0900_as_cs       | utf8mb4  | 286 |         | Yes      |       0 | NO PAD        |
| utf8mb4_es_trad_0900_ai_ci  | utf8mb4  | 270 |         | Yes      |       0 | NO PAD        |
| utf8mb4_es_trad_0900_as_cs  | utf8mb4  | 293 |         | Yes      |       0 | NO PAD        |
| utf8mb4_et_0900_ai_ci       | utf8mb4  | 262 |         | Yes      |       0 | NO PAD        |
| utf8mb4_et_0900_as_cs       | utf8mb4  | 285 |         | Yes      |       0 | NO PAD        |
| utf8mb4_general_ci          | utf8mb4  |  45 |         | Yes      |       1 | PAD SPACE     |
| utf8mb4_german2_ci          | utf8mb4  | 244 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_gl_0900_ai_ci       | utf8mb4  | 320 |         | Yes      |       0 | NO PAD        |
| utf8mb4_gl_0900_as_cs       | utf8mb4  | 321 |         | Yes      |       0 | NO PAD        |
| utf8mb4_hr_0900_ai_ci       | utf8mb4  | 275 |         | Yes      |       0 | NO PAD        |
| utf8mb4_hr_0900_as_cs       | utf8mb4  | 298 |         | Yes      |       0 | NO PAD        |
| utf8mb4_hungarian_ci        | utf8mb4  | 242 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_hu_0900_ai_ci       | utf8mb4  | 274 |         | Yes      |       0 | NO PAD        |
| utf8mb4_hu_0900_as_cs       | utf8mb4  | 297 |         | Yes      |       0 | NO PAD        |
| utf8mb4_icelandic_ci        | utf8mb4  | 225 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_is_0900_ai_ci       | utf8mb4  | 257 |         | Yes      |       0 | NO PAD        |
| utf8mb4_is_0900_as_cs       | utf8mb4  | 280 |         | Yes      |       0 | NO PAD        |
| utf8mb4_ja_0900_as_cs       | utf8mb4  | 303 |         | Yes      |       0 | NO PAD        |
| utf8mb4_ja_0900_as_cs_ks    | utf8mb4  | 304 |         | Yes      |      24 | NO PAD        |
| utf8mb4_latvian_ci          | utf8mb4  | 226 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_la_0900_ai_ci       | utf8mb4  | 271 |         | Yes      |       0 | NO PAD        |
| utf8mb4_la_0900_as_cs       | utf8mb4  | 294 |         | Yes      |       0 | NO PAD        |
| utf8mb4_lithuanian_ci       | utf8mb4  | 236 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_lt_0900_ai_ci       | utf8mb4  | 268 |         | Yes      |       0 | NO PAD        |
| utf8mb4_lt_0900_as_cs       | utf8mb4  | 291 |         | Yes      |       0 | NO PAD        |
| utf8mb4_lv_0900_ai_ci       | utf8mb4  | 258 |         | Yes      |       0 | NO PAD        |
| utf8mb4_lv_0900_as_cs       | utf8mb4  | 281 |         | Yes      |       0 | NO PAD        |
| utf8mb4_mn_cyrl_0900_ai_ci  | utf8mb4  | 322 |         | Yes      |       0 | NO PAD        |
| utf8mb4_mn_cyrl_0900_as_cs  | utf8mb4  | 323 |         | Yes      |       0 | NO PAD        |
| utf8mb4_nb_0900_ai_ci       | utf8mb4  | 310 |         | Yes      |       0 | NO PAD        |
| utf8mb4_nb_0900_as_cs       | utf8mb4  | 311 |         | Yes      |       0 | NO PAD        |
| utf8mb4_nn_0900_ai_ci       | utf8mb4  | 312 |         | Yes      |       0 | NO PAD        |
| utf8mb4_nn_0900_as_cs       | utf8mb4  | 313 |         | Yes      |       0 | NO PAD        |
| utf8mb4_persian_ci          | utf8mb4  | 240 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_pl_0900_ai_ci       | utf8mb4  | 261 |         | Yes      |       0 | NO PAD        |
| utf8mb4_pl_0900_as_cs       | utf8mb4  | 284 |         | Yes      |       0 | NO PAD        |
| utf8mb4_polish_ci           | utf8mb4  | 229 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_romanian_ci         | utf8mb4  | 227 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_roman_ci            | utf8mb4  | 239 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_ro_0900_ai_ci       | utf8mb4  | 259 |         | Yes      |       0 | NO PAD        |
| utf8mb4_ro_0900_as_cs       | utf8mb4  | 282 |         | Yes      |       0 | NO PAD        |
| utf8mb4_ru_0900_ai_ci       | utf8mb4  | 306 |         | Yes      |       0 | NO PAD        |
| utf8mb4_ru_0900_as_cs       | utf8mb4  | 307 |         | Yes      |       0 | NO PAD        |
| utf8mb4_sinhala_ci          | utf8mb4  | 243 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_sk_0900_ai_ci       | utf8mb4  | 269 |         | Yes      |       0 | NO PAD        |
| utf8mb4_sk_0900_as_cs       | utf8mb4  | 292 |         | Yes      |       0 | NO PAD        |
| utf8mb4_slovak_ci           | utf8mb4  | 237 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_slovenian_ci        | utf8mb4  | 228 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_sl_0900_ai_ci       | utf8mb4  | 260 |         | Yes      |       0 | NO PAD        |
| utf8mb4_sl_0900_as_cs       | utf8mb4  | 283 |         | Yes      |       0 | NO PAD        |
| utf8mb4_spanish2_ci         | utf8mb4  | 238 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_spanish_ci          | utf8mb4  | 231 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_sr_latn_0900_ai_ci  | utf8mb4  | 314 |         | Yes      |       0 | NO PAD        |
| utf8mb4_sr_latn_0900_as_cs  | utf8mb4  | 315 |         | Yes      |       0 | NO PAD        |
| utf8mb4_sv_0900_ai_ci       | utf8mb4  | 264 |         | Yes      |       0 | NO PAD        |
| utf8mb4_sv_0900_as_cs       | utf8mb4  | 287 |         | Yes      |       0 | NO PAD        |
| utf8mb4_swedish_ci          | utf8mb4  | 232 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_tr_0900_ai_ci       | utf8mb4  | 265 |         | Yes      |       0 | NO PAD        |
| utf8mb4_tr_0900_as_cs       | utf8mb4  | 288 |         | Yes      |       0 | NO PAD        |
| utf8mb4_turkish_ci          | utf8mb4  | 233 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_unicode_520_ci      | utf8mb4  | 246 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_unicode_ci          | utf8mb4  | 224 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_vietnamese_ci       | utf8mb4  | 247 |         | Yes      |       8 | PAD SPACE     |
| utf8mb4_vi_0900_ai_ci       | utf8mb4  | 277 |         | Yes      |       0 | NO PAD        |
| utf8mb4_vi_0900_as_cs       | utf8mb4  | 300 |         | Yes      |       0 | NO PAD        |
| utf8mb4_zh_0900_as_cs       | utf8mb4  | 308 |         | Yes      |       0 | NO PAD        |
+-----------------------------+----------+-----+---------+----------+---------+---------------+
286 rows in set (0.01 sec)

艾莉丝这里查到的有点多，哈哈，uu们自己使用show collation;可能没有艾莉丝这么多，这是正常的。

2 ~> 过渡

接下来，艾莉丝分别从创建数据库以及创建案例、字符集和校验规则、操纵数据库这几个方面来详细库的操作。

3 ~> 创建数据库（附带案例）

3.1 创建数据库：语法 + 理解

语法：

bash 复制代码 
CREATE DATABASE [IF NOT EXISTS] db_name [create_specification [, create_specification] ...]

create_specification:
	[DEFAULT] CHARACTER SET charset_name
	[DEFAULT] COLLATE collation_name

说明：

  • 大写的表示关键字
  • []是可选项
  • CHARACTER SET：指定数据库采用的字符集
  • COLLATE：指定数据库字符集的校验规则

3.2 创建数据库的案例

3.2.1 创建名为db1的数据库

bash 复制代码 
create database db1;
  • 说明： 当我们创建数据库没有指定字符集和校验规则时，系统使用默认字符集：utf8，校验规则是：utf8_ general_ ci。

3.2.2 创建一个使用utf8字符集的db2数据库

bash 复制代码 
create database db2 charset=utf8;

3.2.3 创建一个使用utf字符集，并带校对规则的 db3 数据库。

bash 复制代码 
create database db3 charset=utf8 collate utf8_general_ci;

4 ~> 字符集和校验规则

4.1 查看系统默认字符集以及校验规则

bash 复制代码 
show variables like 'character_set_database';
show variables like 'collation_database';

4.2 查看数据库支持的字符集

bash 复制代码 
show charset;

字符集主要是控制用什么语言。比如utf8就可以使用中文。

4.3 查看数据库支持的字符集校验规则

bash 复制代码 
show collation;

4.4 校验规则对数据库的影响

4.4.1 不区分大小写

创建一个数据库，校验规则使用utf8_ general_ ci[不区分大小写]。

bash 复制代码 
create database test1 collate utf8_general_ci;
bash 复制代码 
use test1;
bash 复制代码 
create table person(name varchar(20));
bash 复制代码 
insert into person values('a');
insert into person values('A');
insert into person values('b');
insert into person values('B');

4.4.2 区分大小写

创建一个数据库，校验规则使用utf8_ bin[区分大小写]。

bash 复制代码 
create database test2 collate utf8_bin;
bash 复制代码 
use test2
bash 复制代码 
create table person(name varchar(20));
bash 复制代码 
insert into person values('a');
insert into person values('A');
insert into person values('b');
insert into person values('B');

4.4.3 进行查询

4.4.3.1 不区分大小写的查询以及结果
bash 复制代码 
mysql> use test1;
mysql> select * from person where name='a';
+------+
| name |
+------+
| a   |
| A   |
+------+
2 rows in set (0.01 sec)
4.4.3.2 区分大小写的查询以及结果
bash 复制代码 
mysql> use test2;
mysql> select * from person where name='a';
+------+
| name |
+------+
| a   |
+------+
2 rows in set (0.01 sec)

4.4.4 结果排序

4.4.4.1 不区分大小写排序以及结果
bash 复制代码 
mysql> use test1;
mysql> select * from person order by name;
+------+
| name |
+------+
| a   |
| A   |
| b   |
| B   |
+------+
4.4.4.2 区分大小写排序以及结果
bash 复制代码 
mysql> use test2;
mysql> select * from person order by name;
+------+
| name |
+------+
| A   |
| B   |
| a   |
| b   |
+------+

5 ~> 操纵数据库

5.1 查看数据库

bash 复制代码 
show databases;

5.2 显示创建语句

语法格式：

bash 复制代码 
show create database 数据库名；

示例：

bash 复制代码 
mysql> show create database mytest;
+----------+----------------------------------------------------------------+
| Database | Create Database                                               |
+----------+----------------------------------------------------------------+
| mysql   | CREATE DATABASE `mytest` /*!40100 DEFAULT CHARACTER SET utf8 */ |
+----------+----------------------------------------------------------------+

说明：

  • MySQL建议我们关键字使用大写，但是不是必须的。
  • 数据库名字的反引号``，是为了防止使用的数据库名刚好是关键字
  • /*!40100 default.... */这个不是注释，表示当前mysql版本大于4.01版本，就执行这句话。

5.2 修改数据库

语法格式：

bash 复制代码 
ALTER DATABASE db_name
[alter_spacification [,alter_spacification]...]

alter_spacification:
[DEFAULT] CHARACTER SET charset_name
[DEFAULT] COLLATE collation_name

说明：

  • 对数据库的修改主要指的是修改数据库的字符集，校验规则。

**示例：**将mytest数据库字符集改成gbk。

bash 复制代码 
mysql> alter database mytest charset=gbk;
Query OK, 1 row affected (0.00 sec)
mysql> show create database mytest;
+----------+----------------------------------------------------------------+
| Database | Create Database                                               |
+----------+----------------------------------------------------------------+
| mytest   | CREATE DATABASE `mytest` /*!40100 DEFAULT CHARACTER SET gbk */ |
+----------+----------------------------------------------------------------+

5.3 数据库删除

bash 复制代码 
DROP DATABASE [IF EXISTS] db_ name;

执行删除之后的结果：

  • 数据库内部看不到对应的数据库。
  • 对应的数据库文件夹被删除，级联删除，里面的数据表全部被删。

注意： 不要随意删除数据库。

5.4 备份和恢复：放在最后

5.4.1 备份

语法格式：

bash 复制代码 
# mysqldump -P3306 -u root -p 密码 -B 数据库名 > 数据库备份存储的文件路径

示例： 将mytest库备份到文件（退出连接）

bash 复制代码 
# mysqldump -P3306 -u root -p123456 -B mytest > D:/mytest.sql
  • 这时，可以打开看看mytest.sql文件里的内容，其实把我们整个创建数据库，建表，导入数据的语句都装载这个文件中。

5.4.2 还原

bash 复制代码 
mysql> source D:/mysql-5.7.22/mytest.sql;

5.4.3 注意事项

  • 如果备份的不是整个数据库，而是其中的一张表，怎么做？
bash 复制代码 
# mysqldump -u root -p 数据库名 表名1 表名2 > D:/mytest.sql
  • 同时备份多个数据库
bash 复制代码 
# mysqldump -u root -p -B 数据库名1 数据库名2 ... > 数据库存放路径
  • 如果备份一个数据库时，没有带上-B参数， 在恢复数据库时，需要先创建空数据库，然后使用数据库，再使用source来还原。

5.5 查看连接情况

语法格式：

bash 复制代码 
show processlist

示例：

bash 复制代码 
mysql> show processlist;
+----+------+-----------+------+---------+------+-------+------------------+
| Id | User | Host     | db   | Command | Time | State | Info             |
+----+------+-----------+------+---------+------+-------+------------------+
|  2 | root | localhost | test | Sleep   | 1386 |       | NULL             |
|  3 | root | localhost | NULL | Query   |    0 | NULL | show processlist |
+----+------+-----------+------+---------+------+-------+------------------+

【查看连接情况】 这个操作可以告诉我们当前有哪些用户连接到我们的MySQL，如果查出某个用户不是你正常登陆的，很有可能你的数据库被人入侵了。以后大家发现自己数据库比较慢时，可以用这个指令来查看数据库连接情况。

6 ~> MYSQL操作库部分的思维导图

结尾

uu们，本文的内容到这里就全部结束了，艾莉丝在这里再次感谢您的阅读！

结语：希望对学习MYSQL相关内容的uu有所帮助，不要忘记给博主"一键四连"哦！

往期回顾：

【MYSQL】MYSQL学习的一大重点：数据库基础

🗡博主在这里放了一只小狗，大家看完了摸摸小狗放松一下吧！🗡 ૮₍ ˶ ˊ ᴥ ˋ˶₎ა

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