全球化和本地化

╰+攻爆jí腚メ 2022-05-06 11:00 160阅读 0赞

## 1.什么是字符集？什么是校对集？ ##

*  字符集是字母和符号的集合，每一个字符编码都由字符集决定。
 *  校对集是字母和符号的校对标准。校对集影响着字符的排序和搜索。

## 2.查看字符集和校对集： ##

*  查看mysql支持的字符集：show character set;
    
    **Charset:字符集**
    
    **Description:描述**
    
    **Default collation:默认字符集**
    
    **Maxlen:最大字符长度**
    
        mysql> show character set;
        +----------+-----------------------------+---------------------+--------+
        | Charset  | Description                 | Default collation   | Maxlen |
        +----------+-----------------------------+---------------------+--------+
        | big5     | Big5 Traditional Chinese    | big5_chinese_ci     |      2 |
        | dec8     | DEC West European           | dec8_swedish_ci     |      1 |
        | cp850    | DOS West European           | cp850_general_ci    |      1 |
        | hp8      | HP West European            | hp8_english_ci      |      1 |
        | koi8r    | KOI8-R Relcom Russian       | koi8r_general_ci    |      1 |
        | latin1   | cp1252 West European        | latin1_swedish_ci   |      1 |
        | latin2   | ISO 8859-2 Central European | latin2_general_ci   |      1 |
        | swe7     | 7bit Swedish                | swe7_swedish_ci     |      1 |
        | ascii    | US ASCII                    | ascii_general_ci    |      1 |
        | ujis     | EUC-JP Japanese             | ujis_japanese_ci    |      3 |
        | sjis     | Shift-JIS Japanese          | sjis_japanese_ci    |      2 |
        | hebrew   | ISO 8859-8 Hebrew           | hebrew_general_ci   |      1 |
        | tis620   | TIS620 Thai                 | tis620_thai_ci      |      1 |
        | euckr    | EUC-KR Korean               | euckr_korean_ci     |      2 |
        | koi8u    | KOI8-U Ukrainian            | koi8u_general_ci    |      1 |
        | gb2312   | GB2312 Simplified Chinese   | gb2312_chinese_ci   |      2 |
        | greek    | ISO 8859-7 Greek            | greek_general_ci    |      1 |
        | cp1250   | Windows Central European    | cp1250_general_ci   |      1 |
        | gbk      | GBK Simplified Chinese      | gbk_chinese_ci      |      2 |
        | latin5   | ISO 8859-9 Turkish          | latin5_turkish_ci   |      1 |
        | armscii8 | ARMSCII-8 Armenian          | armscii8_general_ci |      1 |
        | utf8     | UTF-8 Unicode               | utf8_general_ci     |      3 |
        | ucs2     | UCS-2 Unicode               | ucs2_general_ci     |      2 |
        | cp866    | DOS Russian                 | cp866_general_ci    |      1 |
        | keybcs2  | DOS Kamenicky Czech-Slovak  | keybcs2_general_ci  |      1 |
        | macce    | Mac Central European        | macce_general_ci    |      1 |
        | macroman | Mac West European           | macroman_general_ci |      1 |
        | cp852    | DOS Central European        | cp852_general_ci    |      1 |
        | latin7   | ISO 8859-13 Baltic          | latin7_general_ci   |      1 |
        | utf8mb4  | UTF-8 Unicode               | utf8mb4_general_ci  |      4 |
        | cp1251   | Windows Cyrillic            | cp1251_general_ci   |      1 |
        | utf16    | UTF-16 Unicode              | utf16_general_ci    |      4 |
        | utf16le  | UTF-16LE Unicode            | utf16le_general_ci  |      4 |
        | cp1256   | Windows Arabic              | cp1256_general_ci   |      1 |
        | cp1257   | Windows Baltic              | cp1257_general_ci   |      1 |
        | utf32    | UTF-32 Unicode              | utf32_general_ci    |      4 |
        | binary   | Binary pseudo charset       | binary              |      1 |
        | geostd8  | GEOSTD8 Georgian            | geostd8_general_ci  |      1 |
        | cp932    | SJIS for Windows Japanese   | cp932_japanese_ci   |      2 |
        | eucjpms  | UJIS for Windows Japanese   | eucjpms_japanese_ci |      3 |
        +----------+-----------------------------+---------------------+--------+
        40 rows in set
 *  查看mysql支持的校对集：show collation;
    
        mysql> show collation;
        +--------------------------+----------+-----+---------+----------+---------+
        | Collation                | Charset  | Id  | Default | Compiled | Sortlen |
        +--------------------------+----------+-----+---------+----------+---------+
        | big5_chinese_ci          | big5     |   1 | Yes     | Yes      |       1 |
        | big5_bin                 | big5     |  84 |         | Yes      |       1 |
        | dec8_swedish_ci          | dec8     |   3 | Yes     | Yes      |       1 |
        | dec8_bin                 | dec8     |  69 |         | Yes      |       1 |
        | cp850_general_ci         | cp850    |   4 | Yes     | Yes      |       1 |
        | cp850_bin                | cp850    |  80 |         | Yes      |       1 |
        | hp8_english_ci           | hp8      |   6 | Yes     | Yes      |       1 |
        | hp8_bin                  | hp8      |  72 |         | Yes      |       1 |
        | koi8r_general_ci         | koi8r    |   7 | Yes     | Yes      |       1 |
        | koi8r_bin                | koi8r    |  74 |         | Yes      |       1 |
        | latin1_german1_ci        | latin1   |   5 |         | Yes      |       1 |
        | latin1_swedish_ci        | latin1   |   8 | Yes     | Yes      |       1 |
        | latin1_danish_ci         | latin1   |  15 |         | Yes      |       1 |
        | latin1_german2_ci        | latin1   |  31 |         | Yes      |       2 |
        | latin1_bin               | latin1   |  47 |         | Yes      |       1 |
        | latin1_general_ci        | latin1   |  48 |         | Yes      |       1 |
        | latin1_general_cs        | latin1   |  49 |         | Yes      |       1 |
        | latin1_spanish_ci        | latin1   |  94 |         | Yes      |       1 |
        | latin2_czech_cs          | latin2   |   2 |         | Yes      |       4 |
        | latin2_general_ci        | latin2   |   9 | Yes     | Yes      |       1 |
        | latin2_hungarian_ci      | latin2   |  21 |         | Yes      |       1 |
        | latin2_croatian_ci       | latin2   |  27 |         | Yes      |       1 |
        | latin2_bin               | latin2   |  77 |         | Yes      |       1 |
        | swe7_swedish_ci          | swe7     |  10 | Yes     | Yes      |       1 |
        | swe7_bin                 | swe7     |  82 |         | Yes      |       1 |
        | ascii_general_ci         | ascii    |  11 | Yes     | Yes      |       1 |
        | ascii_bin                | ascii    |  65 |         | Yes      |       1 |
        | ujis_japanese_ci         | ujis     |  12 | Yes     | Yes      |       1 |
        | ujis_bin                 | ujis     |  91 |         | Yes      |       1 |
        | sjis_japanese_ci         | sjis     |  13 | Yes     | Yes      |       1 |
        | sjis_bin                 | sjis     |  88 |         | Yes      |       1 |
        | hebrew_general_ci        | hebrew   |  16 | Yes     | Yes      |       1 |
        | hebrew_bin               | hebrew   |  71 |         | Yes      |       1 |
        | tis620_thai_ci           | tis620   |  18 | Yes     | Yes      |       4 |
        | tis620_bin               | tis620   |  89 |         | Yes      |       1 |
        | euckr_korean_ci          | euckr    |  19 | Yes     | Yes      |       1 |
        | euckr_bin                | euckr    |  85 |         | Yes      |       1 |
        | koi8u_general_ci         | koi8u    |  22 | Yes     | Yes      |       1 |
        | koi8u_bin                | koi8u    |  75 |         | Yes      |       1 |
        | gb2312_chinese_ci        | gb2312   |  24 | Yes     | Yes      |       1 |
        | gb2312_bin               | gb2312   |  86 |         | Yes      |       1 |
        | greek_general_ci         | greek    |  25 | Yes     | Yes      |       1 |
        | greek_bin                | greek    |  70 |         | Yes      |       1 |
        | cp1250_general_ci        | cp1250   |  26 | Yes     | Yes      |       1 |
        | cp1250_czech_cs          | cp1250   |  34 |         | Yes      |       2 |
        | cp1250_croatian_ci       | cp1250   |  44 |         | Yes      |       1 |
        | cp1250_bin               | cp1250   |  66 |         | Yes      |       1 |
        | cp1250_polish_ci         | cp1250   |  99 |         | Yes      |       1 |
        | gbk_chinese_ci           | gbk      |  28 | Yes     | Yes      |       1 |
        | gbk_bin                  | gbk      |  87 |         | Yes      |       1 |
        | latin5_turkish_ci        | latin5   |  30 | Yes     | Yes      |       1 |
        | latin5_bin               | latin5   |  78 |         | Yes      |       1 |
        | armscii8_general_ci      | armscii8 |  32 | Yes     | Yes      |       1 |
        | armscii8_bin             | armscii8 |  64 |         | Yes      |       1 |
        | utf8_general_ci          | utf8     |  33 | Yes     | Yes      |       1 |
        | utf8_bin                 | utf8     |  83 |         | Yes      |       1 |
        | utf8_unicode_ci          | utf8     | 192 |         | Yes      |       8 |
        | utf8_icelandic_ci        | utf8     | 193 |         | Yes      |       8 |
        | utf8_latvian_ci          | utf8     | 194 |         | Yes      |       8 |
        | utf8_romanian_ci         | utf8     | 195 |         | Yes      |       8 |
        | utf8_slovenian_ci        | utf8     | 196 |         | Yes      |       8 |
        | utf8_polish_ci           | utf8     | 197 |         | Yes      |       8 |
        | utf8_estonian_ci         | utf8     | 198 |         | Yes      |       8 |
        | utf8_spanish_ci          | utf8     | 199 |         | Yes      |       8 |
        | utf8_swedish_ci          | utf8     | 200 |         | Yes      |       8 |
        | utf8_turkish_ci          | utf8     | 201 |         | Yes      |       8 |
        | utf8_czech_ci            | utf8     | 202 |         | Yes      |       8 |
        | utf8_danish_ci           | utf8     | 203 |         | Yes      |       8 |
        | utf8_lithuanian_ci       | utf8     | 204 |         | Yes      |       8 |
        | utf8_slovak_ci           | utf8     | 205 |         | Yes      |       8 |
        | utf8_spanish2_ci         | utf8     | 206 |         | Yes      |       8 |
        | utf8_roman_ci            | utf8     | 207 |         | Yes      |       8 |
        | utf8_persian_ci          | utf8     | 208 |         | Yes      |       8 |
        | utf8_esperanto_ci        | utf8     | 209 |         | Yes      |       8 |
        | utf8_hungarian_ci        | utf8     | 210 |         | Yes      |       8 |
        | utf8_sinhala_ci          | utf8     | 211 |         | Yes      |       8 |
        | utf8_german2_ci          | utf8     | 212 |         | Yes      |       8 |
        | utf8_croatian_ci         | utf8     | 213 |         | Yes      |       8 |
        | utf8_unicode_520_ci      | utf8     | 214 |         | Yes      |       8 |
        | utf8_vietnamese_ci       | utf8     | 215 |         | Yes      |       8 |
        | utf8_general_mysql500_ci | utf8     | 223 |         | Yes      |       1 |
        | ucs2_general_ci          | ucs2     |  35 | Yes     | Yes      |       1 |
        | ucs2_bin                 | ucs2     |  90 |         | Yes      |       1 |
        | ucs2_unicode_ci          | ucs2     | 128 |         | Yes      |       8 |
        | ucs2_icelandic_ci        | ucs2     | 129 |         | Yes      |       8 |
        | ucs2_latvian_ci          | ucs2     | 130 |         | Yes      |       8 |
        | ucs2_romanian_ci         | ucs2     | 131 |         | Yes      |       8 |
        | ucs2_slovenian_ci        | ucs2     | 132 |         | Yes      |       8 |
        | ucs2_polish_ci           | ucs2     | 133 |         | Yes      |       8 |
        | ucs2_estonian_ci         | ucs2     | 134 |         | Yes      |       8 |
        | ucs2_spanish_ci          | ucs2     | 135 |         | Yes      |       8 |
        | ucs2_swedish_ci          | ucs2     | 136 |         | Yes      |       8 |
        | ucs2_turkish_ci          | ucs2     | 137 |         | Yes      |       8 |
        | ucs2_czech_ci            | ucs2     | 138 |         | Yes      |       8 |
        | ucs2_danish_ci           | ucs2     | 139 |         | Yes      |       8 |
        | ucs2_lithuanian_ci       | ucs2     | 140 |         | Yes      |       8 |
        | ucs2_slovak_ci           | ucs2     | 141 |         | Yes      |       8 |
        | ucs2_spanish2_ci         | ucs2     | 142 |         | Yes      |       8 |
        | ucs2_roman_ci            | ucs2     | 143 |         | Yes      |       8 |
        | ucs2_persian_ci          | ucs2     | 144 |         | Yes      |       8 |
        | ucs2_esperanto_ci        | ucs2     | 145 |         | Yes      |       8 |
        | ucs2_hungarian_ci        | ucs2     | 146 |         | Yes      |       8 |
        | ucs2_sinhala_ci          | ucs2     | 147 |         | Yes      |       8 |
        | ucs2_german2_ci          | ucs2     | 148 |         | Yes      |       8 |
        | ucs2_croatian_ci         | ucs2     | 149 |         | Yes      |       8 |
        | ucs2_unicode_520_ci      | ucs2     | 150 |         | Yes      |       8 |
        | ucs2_vietnamese_ci       | ucs2     | 151 |         | Yes      |       8 |
        | ucs2_general_mysql500_ci | ucs2     | 159 |         | Yes      |       1 |
        | cp866_general_ci         | cp866    |  36 | Yes     | Yes      |       1 |
        | cp866_bin                | cp866    |  68 |         | Yes      |       1 |
        | keybcs2_general_ci       | keybcs2  |  37 | Yes     | Yes      |       1 |
        | keybcs2_bin              | keybcs2  |  73 |         | Yes      |       1 |
        | macce_general_ci         | macce    |  38 | Yes     | Yes      |       1 |
        | macce_bin                | macce    |  43 |         | Yes      |       1 |
        | macroman_general_ci      | macroman |  39 | Yes     | Yes      |       1 |
        | macroman_bin             | macroman |  53 |         | Yes      |       1 |
        | cp852_general_ci         | cp852    |  40 | Yes     | Yes      |       1 |
        | cp852_bin                | cp852    |  81 |         | Yes      |       1 |
        | latin7_estonian_cs       | latin7   |  20 |         | Yes      |       1 |
        | latin7_general_ci        | latin7   |  41 | Yes     | Yes      |       1 |
        | latin7_general_cs        | latin7   |  42 |         | Yes      |       1 |
        | latin7_bin               | latin7   |  79 |         | Yes      |       1 |
        | utf8mb4_general_ci       | utf8mb4  |  45 | Yes     | Yes      |       1 |
        | utf8mb4_bin              | utf8mb4  |  46 |         | Yes      |       1 |
        | utf8mb4_unicode_ci       | utf8mb4  | 224 |         | Yes      |       8 |
        | utf8mb4_icelandic_ci     | utf8mb4  | 225 |         | Yes      |       8 |
        | utf8mb4_latvian_ci       | utf8mb4  | 226 |         | Yes      |       8 |
        | utf8mb4_romanian_ci      | utf8mb4  | 227 |         | Yes      |       8 |
        | utf8mb4_slovenian_ci     | utf8mb4  | 228 |         | Yes      |       8 |
        | utf8mb4_polish_ci        | utf8mb4  | 229 |         | Yes      |       8 |
        | utf8mb4_estonian_ci      | utf8mb4  | 230 |         | Yes      |       8 |
        | utf8mb4_spanish_ci       | utf8mb4  | 231 |         | Yes      |       8 |
        | utf8mb4_swedish_ci       | utf8mb4  | 232 |         | Yes      |       8 |
        | utf8mb4_turkish_ci       | utf8mb4  | 233 |         | Yes      |       8 |
        | utf8mb4_czech_ci         | utf8mb4  | 234 |         | Yes      |       8 |
        | utf8mb4_danish_ci        | utf8mb4  | 235 |         | Yes      |       8 |
        | utf8mb4_lithuanian_ci    | utf8mb4  | 236 |         | Yes      |       8 |
        | utf8mb4_slovak_ci        | utf8mb4  | 237 |         | Yes      |       8 |
        | utf8mb4_spanish2_ci      | utf8mb4  | 238 |         | Yes      |       8 |
        | utf8mb4_roman_ci         | utf8mb4  | 239 |         | Yes      |       8 |
        | utf8mb4_persian_ci       | utf8mb4  | 240 |         | Yes      |       8 |
        | utf8mb4_esperanto_ci     | utf8mb4  | 241 |         | Yes      |       8 |
        | utf8mb4_hungarian_ci     | utf8mb4  | 242 |         | Yes      |       8 |
        | utf8mb4_sinhala_ci       | utf8mb4  | 243 |         | Yes      |       8 |
        | utf8mb4_german2_ci       | utf8mb4  | 244 |         | Yes      |       8 |
        | utf8mb4_croatian_ci      | utf8mb4  | 245 |         | Yes      |       8 |
        | utf8mb4_unicode_520_ci   | utf8mb4  | 246 |         | Yes      |       8 |
        | utf8mb4_vietnamese_ci    | utf8mb4  | 247 |         | Yes      |       8 |
        | cp1251_bulgarian_ci      | cp1251   |  14 |         | Yes      |       1 |
        | cp1251_ukrainian_ci      | cp1251   |  23 |         | Yes      |       1 |
        | cp1251_bin               | cp1251   |  50 |         | Yes      |       1 |
        | cp1251_general_ci        | cp1251   |  51 | Yes     | Yes      |       1 |
        | cp1251_general_cs        | cp1251   |  52 |         | Yes      |       1 |
        | utf16_general_ci         | utf16    |  54 | Yes     | Yes      |       1 |
        | utf16_bin                | utf16    |  55 |         | Yes      |       1 |
        | utf16_unicode_ci         | utf16    | 101 |         | Yes      |       8 |
        | utf16_icelandic_ci       | utf16    | 102 |         | Yes      |       8 |
        | utf16_latvian_ci         | utf16    | 103 |         | Yes      |       8 |
        | utf16_romanian_ci        | utf16    | 104 |         | Yes      |       8 |
        | utf16_slovenian_ci       | utf16    | 105 |         | Yes      |       8 |
        | utf16_polish_ci          | utf16    | 106 |         | Yes      |       8 |
        | utf16_estonian_ci        | utf16    | 107 |         | Yes      |       8 |
        | utf16_spanish_ci         | utf16    | 108 |         | Yes      |       8 |
        | utf16_swedish_ci         | utf16    | 109 |         | Yes      |       8 |
        | utf16_turkish_ci         | utf16    | 110 |         | Yes      |       8 |
        | utf16_czech_ci           | utf16    | 111 |         | Yes      |       8 |
        | utf16_danish_ci          | utf16    | 112 |         | Yes      |       8 |
        | utf16_lithuanian_ci      | utf16    | 113 |         | Yes      |       8 |
        | utf16_slovak_ci          | utf16    | 114 |         | Yes      |       8 |
        | utf16_spanish2_ci        | utf16    | 115 |         | Yes      |       8 |
        | utf16_roman_ci           | utf16    | 116 |         | Yes      |       8 |
        | utf16_persian_ci         | utf16    | 117 |         | Yes      |       8 |
        | utf16_esperanto_ci       | utf16    | 118 |         | Yes      |       8 |
        | utf16_hungarian_ci       | utf16    | 119 |         | Yes      |       8 |
        | utf16_sinhala_ci         | utf16    | 120 |         | Yes      |       8 |
        | utf16_german2_ci         | utf16    | 121 |         | Yes      |       8 |
        | utf16_croatian_ci        | utf16    | 122 |         | Yes      |       8 |
        | utf16_unicode_520_ci     | utf16    | 123 |         | Yes      |       8 |
        | utf16_vietnamese_ci      | utf16    | 124 |         | Yes      |       8 |
        | utf16le_general_ci       | utf16le  |  56 | Yes     | Yes      |       1 |
        | utf16le_bin              | utf16le  |  62 |         | Yes      |       1 |
        | cp1256_general_ci        | cp1256   |  57 | Yes     | Yes      |       1 |
        | cp1256_bin               | cp1256   |  67 |         | Yes      |       1 |
        | cp1257_lithuanian_ci     | cp1257   |  29 |         | Yes      |       1 |
        | cp1257_bin               | cp1257   |  58 |         | Yes      |       1 |
        | cp1257_general_ci        | cp1257   |  59 | Yes     | Yes      |       1 |
        | utf32_general_ci         | utf32    |  60 | Yes     | Yes      |       1 |
        | utf32_bin                | utf32    |  61 |         | Yes      |       1 |
        | utf32_unicode_ci         | utf32    | 160 |         | Yes      |       8 |
        | utf32_icelandic_ci       | utf32    | 161 |         | Yes      |       8 |
        | utf32_latvian_ci         | utf32    | 162 |         | Yes      |       8 |
        | utf32_romanian_ci        | utf32    | 163 |         | Yes      |       8 |
        | utf32_slovenian_ci       | utf32    | 164 |         | Yes      |       8 |
        | utf32_polish_ci          | utf32    | 165 |         | Yes      |       8 |
        | utf32_estonian_ci        | utf32    | 166 |         | Yes      |       8 |
        | utf32_spanish_ci         | utf32    | 167 |         | Yes      |       8 |
        | utf32_swedish_ci         | utf32    | 168 |         | Yes      |       8 |
        | utf32_turkish_ci         | utf32    | 169 |         | Yes      |       8 |
        | utf32_czech_ci           | utf32    | 170 |         | Yes      |       8 |
        | utf32_danish_ci          | utf32    | 171 |         | Yes      |       8 |
        | utf32_lithuanian_ci      | utf32    | 172 |         | Yes      |       8 |
        | utf32_slovak_ci          | utf32    | 173 |         | Yes      |       8 |
        | utf32_spanish2_ci        | utf32    | 174 |         | Yes      |       8 |
        | utf32_roman_ci           | utf32    | 175 |         | Yes      |       8 |
        | utf32_persian_ci         | utf32    | 176 |         | Yes      |       8 |
        | utf32_esperanto_ci       | utf32    | 177 |         | Yes      |       8 |
        | utf32_hungarian_ci       | utf32    | 178 |         | Yes      |       8 |
        | utf32_sinhala_ci         | utf32    | 179 |         | Yes      |       8 |
        | utf32_german2_ci         | utf32    | 180 |         | Yes      |       8 |
        | utf32_croatian_ci        | utf32    | 181 |         | Yes      |       8 |
        | utf32_unicode_520_ci     | utf32    | 182 |         | Yes      |       8 |
        | utf32_vietnamese_ci      | utf32    | 183 |         | Yes      |       8 |
        | binary                   | binary   |  63 | Yes     | Yes      |       1 |
        | geostd8_general_ci       | geostd8  |  92 | Yes     | Yes      |       1 |
        | geostd8_bin              | geostd8  |  93 |         | Yes      |       1 |
        | cp932_japanese_ci        | cp932    |  95 | Yes     | Yes      |       1 |
        | cp932_bin                | cp932    |  96 |         | Yes      |       1 |
        | eucjpms_japanese_ci      | eucjpms  |  97 | Yes     | Yes      |       1 |
        | eucjpms_bin              | eucjpms  |  98 |         | Yes      |       1 |
        +--------------------------+----------+-----+---------+----------+---------+
        219 rows in set
 *  查看服务端默认的字符集：show variables like ‘char%’;
    
    **character\_set\_client:认为客户端传输数据的字符集**
    
    **character\_set\_connection:认为“连接”的字符集，可以认为是客户端和服务端中间的翻译人**
    
    **character\_set\_database:创建数据库默认的字符集**
    
    **character\_set\_filesystem:存储数据库文件的字符集**
    
    **character\_set\_results:返回给客户端的数据的字符集**
    
    **character\_set\_server:服务端的数据的字符集**
    
    **character\_set\_system:mysql系统的字符集**
    
    **character\_sets\_dir:目录**
    
        mysql> show variables like 'char%';
        +--------------------------+---------------------------------------------------------+
        | Variable_name            | Value                                                   |
        +--------------------------+---------------------------------------------------------+
        | character_set_client     | utf8                                                    |
        | character_set_connection | utf8                                                    |
        | character_set_database   | utf8                                                    |
        | character_set_filesystem | binary                                                  |
        | character_set_results    | utf8                                                    |
        | character_set_server     | utf8                                                    |
        | character_set_system     | utf8                                                    |
        | character_sets_dir       | C:\Program Files\MySQL\MySQL Server 5.6\share\charsets\ |
        +--------------------------+---------------------------------------------------------+
        8 rows in set
 *  查看服务端默认的校对集：show variables like ‘collation%’;
    
    **collation\_connection:“连接”的校对集**
    
    **collation\_database:创建数据库默认的校对集**
    
    **collation\_server:服务端数据的校对集**
    
        mysql> show variables like 'collation%';
        +----------------------+-----------------+
        | Variable_name        | Value           |
        +----------------------+-----------------+
        | collation_connection | utf8_general_ci |
        | collation_database   | utf8_general_ci |
        | collation_server     | utf8_general_ci |
        +----------------------+-----------------+
        3 rows in set

## 3.设置字符集和校对集 ##

### 设置数据库数据表的字符集： ###

*  实际上，字符集很少是服务器范围（甚至数据库范围）的设置。不同的表，甚至不同的列都可能需要不同的字符集，而且两者都可以在创建表时指定【语出mysql必知必会】。下面介绍不使用默认配置来创建数据库、数据表
 *  
 *   *  创建数据库：create database 数据库名 charset 字符集 collate 校对集;【校对集并不是必要的，每一个字符集都有默认的校对集，如果没有校对集将使用默认的】
     *  
     *      mysql> create database test6 charset utf8 collate utf8_general_ci;
 *   *  创建数据表：create table 表名 charset 字符集 collate 校对集;
     *  
     *      create table t1(id int) charset utf8 collate utf8_general_ci;
 *   *  给某一列指定字符集和校对集：
     *      create table t3(name varchar(15) charset utf8 collate utf8_general_ci);

### 设置服务端和客户端的字符集: ###

*  语法：set character\_set\_xxx =字符集; 【character\_set\_xxx是上面查看字符集中的服务端的各个默认字符集，意义在上面已经标上了】【这种设置是会话级的，仅在当次连接生效。】
 *  如果想要永久修改服务端的字符集：windows下修改my.ini文件【就是mysql的配置文件，可以从mysql服务中查看在哪】，在mysqld中将character-set-server的值修改为指定的字符集【修改的是服务端的字符集】

### 补充： ###

*  不可永久配置服务端认为客户端的字符集，每一个连接过来的客户端的字符集都是不确定的，**应该由客户端设置当次连接的字符集来指定字符集。**

## 4.mysql中的中文数据问题： ##

*  mysql中的中文数据问题本质上还是字符集问题，想要识别和存储中文数据，必须设置能编码中文的字符集。
 *  gbk和utf8都是支持mysql的，一般都是将mysql的字符集更改成utf8来识别中文。
 *  如何配置（以gbk为例）：
 *   *  首先要考虑的一个是：\*\*如果你使用命令行模式，默认情况下字符的编码格式是gbk的，\*\*也就是说客户端的数据编码是gbk的；
     *  如果服务端要识别客户端传来的中文，那么需要设置服务端认为客户端的字符集为gbk;set character\_set\_client =‘gbk’;
     *  如果服务端要返回中文给客户端，需要将服务端返回给客户端的数据的字符集设置为gbk;set character\_set\_results =‘gbk’;
     *  对于单次会话，可以直接使用set names = ‘gbk’;【执行set names= 'gbk’就是把character\_set\_client、character\_set\_connection、character\_set\_results这3个参数值都设为gbk】