{"id":247,"date":"2023-02-24T06:05:59","date_gmt":"2023-02-23T22:05:59","guid":{"rendered":"https:\/\/www.appblog.cn\/?p=247"},"modified":"2023-04-30T15:19:46","modified_gmt":"2023-04-30T07:19:46","slug":"mysql-process-duplicate-data","status":"publish","type":"post","link":"https:\/\/www.appblog.cn\/index.php\/2023\/02\/24\/mysql-process-duplicate-data\/","title":{"rendered":"MySQL \u5904\u7406\u91cd\u590d\u6570\u636e"},"content":{"rendered":"

\u6709\u4e9b MySQL \u6570\u636e\u8868\u4e2d\u53ef\u80fd\u5b58\u5728\u91cd\u590d\u7684\u8bb0\u5f55\uff0c\u6709\u4e9b\u60c5\u51b5\u6211\u4eec\u5141\u8bb8\u91cd\u590d\u6570\u636e\u7684\u5b58\u5728\uff0c\u4f46\u6709\u65f6\u5019\u6211\u4eec\u4e5f\u9700\u8981\u5220\u9664\u8fd9\u4e9b\u91cd\u590d\u7684\u6570\u636e\u3002<\/p>\n

\u90a3\u4e48\u5982\u4f55\u9632\u6b62\u6570\u636e\u8868\u51fa\u73b0\u91cd\u590d\u6570\u636e\u53ca\u5982\u4f55\u5220\u9664\u6570\u636e\u8868\u4e2d\u7684\u91cd\u590d\u6570\u636e<\/p>\n

\u9632\u6b62\u8868\u4e2d\u51fa\u73b0\u91cd\u590d\u6570\u636e<\/h2>\n

<\/p>\n

\u53ef\u4ee5\u5728 MySQL \u6570\u636e\u8868\u4e2d\u8bbe\u7f6e\u6307\u5b9a\u7684\u5b57\u6bb5\u4e3aPRIMARY KEY<\/code>\uff08\u4e3b\u952e\uff09\u6216\u8005UNIQUE<\/code>\uff08\u552f\u4e00\uff09 \u7d22\u5f15\u6765\u4fdd\u8bc1\u6570\u636e\u7684\u552f\u4e00\u6027\u3002<\/p>\n

\u5c1d\u8bd5\u4e00\u4e2a\u5b9e\u4f8b\uff1a\u4e0b\u8868\u4e2d\u65e0\u7d22\u5f15\u53ca\u4e3b\u952e\uff0c\u6240\u4ee5\u8be5\u8868\u5141\u8bb8\u51fa\u73b0\u591a\u6761\u91cd\u590d\u8bb0\u5f55\u3002<\/p>\n

CREATE TABLE person_tbl\n(\n    first_name CHAR(20),\n    last_name CHAR(20),\n    sex CHAR(10)\n);<\/code><\/pre>\n
\u5982\u679c\u60f3\u8bbe\u7f6e\u8868\u4e2d\u5b57\u6bb5first_name<\/code>\uff0clast_name<\/code>\u6570\u636e\u4e0d\u80fd\u91cd\u590d\uff0c\u53ef\u4ee5\u8bbe\u7f6e\u53cc\u4e3b\u952e\u6a21\u5f0f\u6765\u8bbe\u7f6e\u6570\u636e\u7684\u552f\u4e00\u6027\uff0c\u5982\u679c\u8bbe\u7f6e\u4e86\u53cc\u4e3b\u952e\uff0c\u90a3\u4e48\u53cc\u4e3b\u952e\u7684\u9ed8\u8ba4\u503c\u4e0d\u80fd\u4e3aNULL<\/code>\uff0c\u53ef\u8bbe\u7f6e\u4e3aNOT NULL<\/code>\u3002\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n
CREATE TABLE person_tbl\n(\n   first_name CHAR(20) NOT NULL,\n   last_name CHAR(20) NOT NULL,\n   sex CHAR(10),\n   PRIMARY KEY (last_name, first_name)\n);<\/code><\/pre>\n
\u53e6\u4e00\u79cd\u8bbe\u7f6e\u6570\u636e\u7684\u552f\u4e00\u6027\u65b9\u6cd5\u662f\u6dfb\u52a0\u4e00\u4e2aUNIQUE<\/code>\u7d22\u5f15\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n
CREATE TABLE person_tbl\n(\n   first_name CHAR(20) NOT NULL,\n   last_name CHAR(20) NOT NULL,\n   sex CHAR(10),\n   UNIQUE (last_name, first_name)\n);<\/code><\/pre>\n
\u5982\u679c\u6211\u4eec\u8bbe\u7f6e\u4e86\u552f\u4e00\u7d22\u5f15\uff0c\u90a3\u4e48\u5728\u63d2\u5165\u91cd\u590d\u6570\u636e\u65f6\uff0cSQL \u8bed\u53e5\u5c06\u65e0\u6cd5\u6267\u884c\u6210\u529f\uff0c\u5e76\u629b\u51fa\u9519\u3002<\/p>\n
INSERT IGNORE INTO<\/code>\u4e0eINSERT INTO<\/code>\u7684\u533a\u522b\u5c31\u662fINSERT IGNORE<\/code>\u4f1a\u5ffd\u7565\u6570\u636e\u5e93\u4e2d\u5df2\u7ecf\u5b58\u5728\u7684\u6570\u636e\uff0c\u5982\u679c\u6570\u636e\u5e93\u6ca1\u6709\u6570\u636e\uff0c\u5c31\u63d2\u5165\u65b0\u7684\u6570\u636e\uff0c\u5982\u679c\u6709\u6570\u636e\u7684\u8bdd\u5c31\u8df3\u8fc7\u8fd9\u6761\u6570\u636e\u3002\u8fd9\u6837\u5c31\u53ef\u4ee5\u4fdd\u7559\u6570\u636e\u5e93\u4e2d\u5df2\u7ecf\u5b58\u5728\u6570\u636e\uff0c\u8fbe\u5230\u5728\u95f4\u9699\u4e2d\u63d2\u5165\u6570\u636e\u7684\u76ee\u7684\u3002<\/p>\n
\u4ee5\u4e0b\u5b9e\u4f8b\u4f7f\u7528INSERT IGNORE INTO<\/code>\uff0c\u6267\u884c\u540e\u4e0d\u4f1a\u51fa\u9519\uff0c\u4e5f\u4e0d\u4f1a\u5411\u6570\u636e\u8868\u4e2d\u63d2\u5165\u91cd\u590d\u6570\u636e\uff1a<\/p>\n
mysql> INSERT IGNORE INTO person_tbl (last_name, first_name)\n    -> VALUES( 'Jay', 'Thomas');\nQuery OK, 1 row affected (0.00 sec)\nmysql> INSERT IGNORE INTO person_tbl (last_name, first_name)\n    -> VALUES( 'Jay', 'Thomas');\nQuery OK, 0 rows affected (0.00 sec)<\/code><\/pre>\n
INSERT IGNORE INTO<\/code>\u5f53\u63d2\u5165\u6570\u636e\u65f6\uff0c\u5728\u8bbe\u7f6e\u8bb0\u5f55\u7684\u552f\u4e00\u6027\u540e\uff0c\u5982\u679c\u63d2\u5165\u91cd\u590d\u6570\u636e\uff0c\u5c06\u4e0d\u8fd4\u56de\u9519\u8bef\uff0c\u53ea\u4ee5\u8b66\u544a\u5f62\u5f0f\u8fd4\u56de\u3002\u800cREPLACE INTO<\/code>\u5982\u679c\u5b58\u5728primary<\/code>\u6216unique<\/code>\u76f8\u540c\u7684\u8bb0\u5f55\uff0c\u5219\u5148\u5220\u9664\u6389\uff0c\u518d\u63d2\u5165\u65b0\u8bb0\u5f55\u3002<\/p>\n
\u7edf\u8ba1\u91cd\u590d\u6570\u636e<\/h2>\n
\u4ee5\u4e0b\u6211\u4eec\u5c06\u7edf\u8ba1\u8868\u4e2dfirst_name<\/code>\u548clast_name<\/code>\u7684\u91cd\u590d\u8bb0\u5f55\u6570\uff1a<\/p>\n
mysql> SELECT COUNT(*) as repetitions, last_name, first_name\n    -> FROM person_tbl\n    -> GROUP BY last_name, first_name\n    -> HAVING repetitions > 1;<\/code><\/pre>\n
\u4ee5\u4e0a\u67e5\u8be2\u8bed\u53e5\u5c06\u8fd4\u56deperson_tbl<\/code>\u8868\u4e2d\u91cd\u590d\u7684\u8bb0\u5f55\u6570\u3002\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u67e5\u8be2\u91cd\u590d\u7684\u503c\uff0c\u8bf7\u6267\u884c\u4ee5\u4e0b\u64cd\u4f5c\uff1a<\/p>\n
    \n
  • \u786e\u5b9a\u54ea\u4e00\u5217\u5305\u542b\u7684\u503c\u53ef\u80fd\u4f1a\u91cd\u590d<\/li>\n
  • \u5728\u5217\u9009\u62e9\u5217\u8868\u4f7f\u7528COUNT(*)<\/code>\u5217\u51fa\u7684\u90a3\u4e9b\u5217<\/li>\n
  • \u5728GROUP BY<\/code>\u5b50\u53e5\u4e2d\u5217\u51fa\u7684\u5217<\/li>\n
  • HAVING<\/code>\u5b50\u53e5\u8bbe\u7f6e\u91cd\u590d\u6570\u5927\u4e8e1<\/li>\n<\/ul>\n
    \u8fc7\u6ee4\u91cd\u590d\u6570\u636e<\/h2>\n
    \u5982\u679c\u9700\u8981\u8bfb\u53d6\u4e0d\u91cd\u590d\u7684\u6570\u636e\u53ef\u4ee5\u5728SELECT<\/code>\u8bed\u53e5\u4e2d\u4f7f\u7528DISTINCT<\/code>\u5173\u952e\u5b57\u6765\u8fc7\u6ee4\u91cd\u590d\u6570\u636e\u3002<\/p>\n
    mysql> SELECT DISTINCT last_name, first_name\n    -> FROM person_tbl;<\/code><\/pre>\n
    \u4e5f\u53ef\u4ee5\u4f7f\u7528 GROUP BY \u6765\u8bfb\u53d6\u6570\u636e\u8868\u4e2d\u4e0d\u91cd\u590d\u7684\u6570\u636e\uff1a<\/p>\n
    mysql> SELECT last_name, first_name\n    -> FROM person_tbl\n    -> GROUP BY (last_name, first_name);<\/code><\/pre>\n
    \u5220\u9664\u91cd\u590d\u6570\u636e<\/h2>\n
    \u5982\u679c\u60f3\u5220\u9664\u6570\u636e\u8868\u4e2d\u7684\u91cd\u590d\u6570\u636e\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u7684SQL\u8bed\u53e5\uff1a<\/p>\n
    mysql> CREATE TABLE tmp SELECT last_name, first_name, sex FROM person_tbl GROUP BY (last_name, first_name, sex);\nmysql> DROP TABLE person_tbl;\nmysql> ALTER TABLE tmp RENAME TO person_tbl;<\/code><\/pre>\n
    \u5f53\u7136\u4e5f\u53ef\u4ee5\u5728\u6570\u636e\u8868\u4e2d\u6dfb\u52a0INDEX<\/code>\uff08\u7d22\u5f15\uff09\u548cPRIMAY KEY<\/code>\uff08\u4e3b\u952e\uff09\u8fd9\u79cd\u7b80\u5355\u7684\u65b9\u6cd5\u6765\u5220\u9664\u8868\u4e2d\u7684\u91cd\u590d\u8bb0\u5f55\u3002\u65b9\u6cd5\u5982\u4e0b\uff1a<\/p>\n
    mysql> ALTER IGNORE TABLE person_tbl\n    -> ADD PRIMARY KEY (last_name, first_name);<\/code><\/pre>\n
    \u67e5\u8be2\u91cd\u590d\u6570\u636e<\/h2>\n
    select \u5217\u540d1, count(\u5217\u540d1) as count \nfrom \u8868\u540d\ngroup by \u5217\u540d1\nhaving count>1 and \u5176\u4ed6\u6761\u4ef6<\/code><\/pre>\n
    select \u5217\u540d1, \u5217\u540d2, count(\u5217\u540d1) as count \nfrom \u8868\u540d\ngroup by \u5217\u540d1, \u5217\u540d2 \nhaving count>1 and \u5176\u4ed6\u6761\u4ef6<\/code><\/pre>\n
    \u539f\u7406\uff1a\u5148\u6309\u7167\u8981\u67e5\u8be2\u51fa\u73b0\u91cd\u590d\u6570\u636e\u7684\u5217\uff0c\u8fdb\u884c\u5206\u7ec4\u67e5\u8be2\u3002count > 1<\/code>\u4ee3\u8868\u51fa\u73b0 2 \u6b21\u6216 2 \u6b21\u4ee5\u4e0a<\/p>\n
    \/*\u67e5\u8be2\u91cd\u590d\u6570\u636e*\/\nselect serialnum,cdate,count(*) as count \nfrom test \ngroup by serialnum,cdate having count>1 and cdate>='2018-08-20 00:00:00';<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
    \u6709\u4e9b MySQL \u6570\u636e\u8868\u4e2d\u53ef\u80fd\u5b58\u5728\u91cd\u590d\u7684\u8bb0\u5f55\uff0c\u6709\u4e9b\u60c5\u51b5\u6211\u4eec\u5141\u8bb8\u91cd\u590d\u6570\u636e\u7684\u5b58\u5728\uff0c\u4f46\u6709\u65f6\u5019\u6211\u4eec\u4e5f\u9700\u8981\u5220\u9664\u8fd9\u4e9b\u91cd\u590d\u7684 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"class_list":["post-247","post","type-post","status-publish","format-standard","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/247","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=247"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/247\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=247"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=247"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}