{"id":308761,"date":"2024-01-18T22:37:46","date_gmt":"2024-01-18T14:37:46","guid":{"rendered":"https:\/\/www.idc.net\/help\/308761\/"},"modified":"2024-01-18T22:37:46","modified_gmt":"2024-01-18T14:37:46","slug":"%e6%95%99%e6%82%a8%e5%a6%82%e4%bd%95%e5%b0%86%e4%b8%8d%e5%90%8c%e7%9a%84mysql%e5%ad%97%e7%ac%a6%e9%9b%86%e8%bd%ac%e5%8c%96%e6%88%90%e7%bb%9f%e4%b8%80%e7%9a%84%e5%ad%97%e7%ac%a6%e9%9b%86","status":"publish","type":"post","link":"https:\/\/idc.net\/help\/308761\/","title":{"rendered":"\u6559\u60a8\u5982\u4f55\u5c06\u4e0d\u540c\u7684MySQL\u5b57\u7b26\u96c6\u8f6c\u5316\u6210\u7edf\u4e00\u7684\u5b57\u7b26\u96c6"},"content":{"rendered":"

\u4e0b\u9762\u4e3a\u60a8\u4ecb\u7ecd\u7684MySQL\u5b57\u7b26\u96c6\u5904\u7406\u65b9\u6cd5\u662f\u5c06\u4e0d\u540c\u7684MySQL\u5b57\u7b26\u96c6\uff0c\u8f6c\u5316\u6210\u7edf\u4e00\u7684\u5b57\u7b26\u96c6\u3002 \u8be5\u65b9\u6cd5\u4f9b\u60a8\u53c2\u8003\uff0c\u5e0c\u671b\u5bf9\u60a8\u5b66\u4e60MySQL\u5b57\u7b26\u96c6\u65b9\u9762\u80fd\u6709\u6240\u542f\u8fea\u3002<\/p>\n

\n \n \n 
    \n  \n  \n  
  1. After   an   upgrade   to   MySQL   4.1,   the   statement   fails:        <\/span><\/span><\/li>\n  \n  \n  
  2.  <\/span><\/li>\n  \n  \n  
  3. mysql<\/span>><\/span>   SELECT   SUBSTRING_INDEX(USER(),'@',1);      <\/span><\/li>\n  \n  \n  
  4.  <\/span><\/li>\n  \n  \n  
  5. ERROR   1267   (HY000):   Illegal   mix   of   collations      <\/span><\/li>\n  \n  \n  
  6.  <\/span><\/li>\n  \n  \n  
  7. (utf8_general_ci,IMPLICIT)   and   (latin1_swedish_ci,COERCIBLE)      <\/span><\/li>\n  \n  \n  
  8.  <\/span><\/li>\n  \n  \n  
  9. for   operation   'substr_index'      <\/span><\/li>\n  \n  \n  
  10.  <\/span><\/li>\n  \n  \n  
  11. The   reason   this   occurs   is   that   usernames   are   stored   using   UTF8   (see   section   11.6   UTF8   for   Metadata).   As   a   result,   the   USER()   function   and   the   literal   string   '@'   have   different   character   sets   (and   thus   different   collations):        <\/span><\/li>\n  \n  \n  
  12.  <\/span><\/li>\n  \n  \n  
  13. mysql<\/span>><\/span>   SELECT   COLLATION(USER()),   COLLATION('@');      <\/span><\/li>\n  \n  \n  
  14.  <\/span><\/li>\n  \n  \n  
  15. +-------------------+-------------------+      <\/span><\/li>\n  \n  \n  
  16.  <\/span><\/li>\n  \n  \n  
  17. |   COLLATION(USER())   |   COLLATION('@')         |      <\/span><\/li>\n  \n  \n  
  18.  <\/span><\/li>\n  \n  \n  
  19. +-------------------+-------------------+      <\/span><\/li>\n  \n  \n  
  20.  <\/span><\/li>\n  \n  \n  
  21. |   utf8_general_ci       |   latin1_swedish_ci   |      <\/span><\/li>\n  \n  \n  
  22.  <\/span><\/li>\n  \n  \n  
  23. +-------------------+-------------------+      <\/span><\/li>\n  \n  \n  
  24.  <\/span><\/li>\n  \n  \n  
  25. One   way   to   deal   with   this   is   to   tell   MySQL to   interpret   the   literal   string   as   utf8:        <\/span><\/li>\n  \n  \n  
  26.  <\/span><\/li>\n  \n  \n  
  27. mysql<\/span>><\/span>   SELECT   SUBSTRING_INDEX(USER(),_utf8'@',1);      <\/span><\/li>\n  \n  \n  
  28.  <\/span><\/li>\n  \n  \n  
  29. +------------------------------------+      <\/span><\/li>\n  \n  \n  
  30.  <\/span><\/li>\n  \n  \n  
  31. |   SUBSTRING_INDEX(USER(),_utf8'@',1)   |      <\/span><\/li>\n  \n  \n  
  32.  <\/span><\/li>\n  \n  \n  
  33. +------------------------------------+      <\/span><\/li>\n  \n  \n  
  34.  <\/span><\/li>\n  \n  \n  
  35. |   root                                                               |      <\/span><\/li>\n  \n  \n  
  36.  <\/span><\/li>\n  \n  \n  
  37. +------------------------------------+      <\/span><\/li>\n  \n  \n  
  38.  <\/span><\/li>\n  \n  \n  
  39. Another   way   is   to   change   the   connection   character   set   and   collation   to   utf8.   You   can   do   that   with   SET   NAMES   'utf8'   or   by   setting   the   character_set_connection   and   collation_connection   system   variables   directly.        <\/span><\/li>\n  \n  \n  
  40.  <\/span><\/li>\n \n \n <\/ol><\/pre>\n
    \u8868\u7684\u7f16\u7801\u8f6c\u6362\u53ef\u4ee5\u7528\uff1a\uff08MySQL   Version   >   4.12\uff09   <\/p>\n
    \n \n \n 
      \n  \n  \n  
    1. ALTER   TABLE   tbl_name   CONVERT   TO   CHARACTER   SET   charset_name;      <\/span><\/span><\/li>\n  \n  \n  
    2.  <\/span><\/li>\n \n \n <\/ol><\/pre>\n
      \u4e4b\u524d\u7684\u7248\u672c\u53ef\u4ee5\u7528\uff1a   <\/p>\n
      \n \n \n 
        \n  \n  \n  
      1. ALTER   TABLE   tbl_name   CHARACTER   SET   charset_name;   <\/span><\/span><\/li>\n  \n  \n  
      2.  <\/span><\/li>\n \n \n <\/ol><\/pre>\n
         <\/p>\n
         <\/p>\n
         <\/p>\n
        \u3010\u7f16\u8f91\u63a8\u8350\u3011<\/p>\n
        \u6df1\u5165\u7814\u7a76MySQL\u5220\u9664\u591a\u8868\u6570\u636e<\/p>\n
        \u591a\u4e2aMySQL\u8868\u7ed3\u679c\u96c6\u7ec4\u5408<\/p>\n
        MySQL\u5206\u8868\u5904\u7406\u7684\u5b9e\u73b0\u65b9\u6cd5<\/p>\n
        MySQL\u6388\u6743\u8868\u4f7f\u7528\u793a\u4f8b<\/p>\n
        MySQL\u5185\u5b58\u8868\u7684\u5f0a\u7aef<\/p>\n","protected":false},"excerpt":{"rendered":"
        \u4e0b\u9762\u4e3a\u60a8\u4ecb\u7ecd\u7684MySQL\u5b57\u7b26\u96c6\u5904\u7406\u65b9\u6cd5\u662f\u5c06\u4e0d\u540c\u7684MySQL\u5b57\u7b26\u96c6\uff0c\u8f6c\u5316\u6210\u7edf\u4e00\u7684\u5b57\u7b26\u96c6\u3002 \u8be5\u65b9\u6cd5\u4f9b\u60a8\u53c2 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7038],"tags":[],"class_list":["post-308761","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/308761","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/comments?post=308761"}],"version-history":[{"count":0,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/308761\/revisions"}],"wp:attachment":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media?parent=308761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/categories?post=308761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/tags?post=308761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}