\n\t\u7136\u540e\u5faa\u73af\u63d2\u5165 100 \u4e07\u6761\u6d4b\u8bd5\u6570\u636e\u3002\n<\/p>\n
\r\nDELIMITER ;; \r\n CREATE PROCEDURE test_insert()\r\n BEGIN \r\n declare i int;\r\n set i = 1 ;\r\n WHILE (i < 1000000) DO\r\n INSERT INTO xttblog(`name`,title,`page`,`status`) \r\n VALUES(CONCAT('xttblog_', i),\r\n CONCAT('xttblog_', i),\r\n i, (SELECT FLOOR(RAND() * 2)));\r\n set i = i + 1;\r\n END WHILE;\r\n commit; \r\nEND;; \r\nCALL test_insert();<\/pre>\n\n\t\u9996\u5148\u6211\u4eec\u770b\u4e00\u4e0b\u65e0\u7d22\u5f15\u7684\u60c5\u51b5\uff0cxttblog \u8868\u4e2d\u7684 name \u503c\u5df2\u7ecf\u975e\u5e38\u7684\u6563\u4e86\u3002\u67e5\u8be2\u65f6\u95f4 0.55 \u79d2\u5de6\u53f3\u3002\n<\/p>\n
\r\nSELECT * FROM xttblog WHERE `name` IN\r\n('xttblog_1','xttblog_100','xttblog_1000','xttblog_10000');<\/pre>\n\n\t\u6211\u4eec\u5728\u67e5\u4e00\u4e0b xttblog \u8868\u4e2d\u7684 status in \u7684\u60c5\u51b5\uff0c\u8017\u65f6 17 \u79d2\u5de6\u53f3\u3002\n<\/p>\n
\r\nSELECT * FROM xttblog WHERE `status` IN(0,2);<\/pre>\n\n\t\u901a\u8fc7 EXPLAIN \u5bf9\u4e0a\u9762\u4e24\u6761\u67e5\u8be2\u8bed\u53e5\u8fdb\u884c\u5206\u6790\uff08\u4e0d\u61c2 EXPLAIN \u7684\u53ef\u4ee5\u770b\u6211\u7684\u8fd9\u7bc7\u6587\u7ae0\u300aMySQL \u6027\u80fd\u4f18\u5316\u795e\u5668 Explain \u4f7f\u7528\u6559\u7a0b<\/a>\u300b\uff09\uff0c\u5b83\u4eec\u90fd\u6ca1\u6709\u8d70\u7d22\u5f15\u3002name \u7684\u503c\u56e0\u4e3a\u66f4\u5206\u6563\uff0c\u67e5\u8be2\u901f\u5ea6\u66f4\u5feb\u3002\n<\/p>\n\n\t\u518d\u6765\u770b\u770b\u6709\u7d22\u5f15\u7684\u60c5\u51b5\u4e0b\uff0cin \u7684\u6267\u884c\u6548\u7387\u3002\n<\/p>\n
\r\nSELECT * FROM xttblog WHERE id IN(1,100,1000,10000);<\/pre>\n\n\t\u6211\u4eec\u7684\u4e3b\u952e id \u662f\u4e00\u4e2a\u7d22\u5f15\uff0c\u4e0a\u9762\u8bed\u53e5\u7684\u67e5\u8be2\u8017\u65f6 0.02 \u79d2\u5de6\u53f3\u3002\n<\/p>\n
\n\t\u4e3a\u4e86\u6bd4\u8f83\uff0c\u6211\u4eec\u518d\u7ed9 xttblog \u8868\u7684 name \u5b57\u6bb5\u52a0\u4e0a\u7d22\u5f15\u3002\n<\/p>\n
\r\nCREATE INDEX index_xttblog_name ON xttblog(`name`(255));<\/pre>\n\n\t\u7136\u540e\u6267\u884c\u4e0b\u9762\u7684\u67e5\u8be2\uff1a\n<\/p>\n
\r\nSELECT * FROM xttblog WHERE `name` \r\nIN('xttblog_1','xttblog_100','xttblog_1000','xttblog_10000');<\/pre>\n\n\t\u5f53 name \u5b57\u6bb5\u6dfb\u52a0\u4e86\u7d22\u5f15\u540e\uff0cin \u67e5\u8be2\u8017\u65f6 0.02 \u6beb\u79d2\u5de6\u53f3\u3002\n<\/p>\n
\n\t![\"EXPLAIN](\"https:\/\/images.weserv.nl\/?url=https:\/\/wx1.sinaimg.cn\/large\/8fa5dcfcgy1fynpdixeebj20hp02gmxf.jpg\")
\n<\/p>\n
\n\tEXPLAIN \u5206\u6790\u53d1\u73b0\u5b83\u4eec\u7684 type \u90fd\u662f range\uff0c\u8868\u793a\u4f7f\u7528\u7d22\u5f15\u8303\u56f4\u67e5\u8be2, \u901a\u8fc7\u7d22\u5f15\u5b57\u6bb5\u8303\u56f4\u83b7\u53d6\u8868\u4e2d\u90e8\u5206\u6570\u636e\u8bb0\u5f55. \u8fd9\u4e2a\u7c7b\u578b\u901a\u5e38\u51fa\u73b0\u5728 =\uff0c<>\uff0c>\uff0c>=\uff0c<\uff0c<=\uff0cIS NULL\uff0c<=>\uff0cBETWEEN\uff0cIN() \u64cd\u4f5c\u4e2d\u3002\u800c\u4e14 possible_keys \u7684\u503c\u4e5f\u8868\u660e\u4e86\u5206\u522b\u4f7f\u7528\u4e3b\u952e\u7d22\u5f15\u548c index_xttblog_name \u7d22\u5f15\u3002\u5e76\u4e14\u5728 in \u7d22\u5f15\u7684\u60c5\u51b5\u4e0b\uff0crows \u7684\u503c\uff0c\u5927\u5bb6\u90fd\u53ef\u4ee5\u770b\u5230\u662f 4\u3002\u4ee5\u4e0a\u5c31\u53ef\u4ee5\u8bc1\u660e\u4e86\uff0c\u5728 MySQL 5.6 \u7248\u672c\u4e2d\uff0cin \u5728\u6709\u7d22\u5f15\u7684\u60c5\u51b5\u4e0b\uff0c\u4f1a\u8d70\u7d22\u5f15\u8fdb\u884c\u67e5\u8be2\u3002\n<\/p>\n
\n\t\u867d\u7136 Extra \u7684\u503c\u662f Using where\uff0c\u5b83\u8868\u793a\u4f18\u5316\u5668\u9700\u8981\u901a\u8fc7\u7d22\u5f15\u56de\u8868\u67e5\u8be2\u6570\u636e\u3002\u4f7f\u7528\u4e86 WHERE \u4ece\u53e5\u6765\u9650\u5236\u54ea\u4e9b\u884c\u5c06\u4e0e\u4e0b\u4e00\u5f20\u8868\u5339\u914d\u6216\u8005\u662f\u8fd4\u56de\u7ed9\u7528\u6237\u3002Extra \u5217\u51fa\u73b0 Using where \u8868\u793a MySQL \u670d\u52a1\u5668\u5c06\u5b58\u50a8\u5f15\u64ce\u8fd4\u56de\u670d\u52a1\u5c42\u4ee5\u540e\u518d\u5e94\u7528 WHERE \u6761\u4ef6\u8fc7\u6ee4\u3002\n<\/p>\n
\n\t\u73b0\u5728\u6765\u770b\uff0c\u5728\u56de\u7b54\u9898\u76ee\u4e2d\u7684\u95ee\u9898\u3002MySQL \u7684 in \u67e5\u8be2\u5728 5.5 \u4ee5\u4e0a\u7684\u7248\u672c\u4e2d\u5b58\u50a8\u5f15\u64ce\u90fd\u662f innodb \u7684\uff0c\u6b63\u5e38\u60c5\u51b5\u4e0b\u4f1a\u8d70\u7d22\u5f15\u7684\uff01\u81f3\u4e8e MyISAM \u7684\u60c5\u51b5\u5927\u5bb6\u81ea\u5df1\u53bb\u7814\u7a76\uff0c\u6216\u8005\u6211\u4ee5\u540e\u62bd\u65f6\u95f4\u4e86\u6765\u5199\uff01\n<\/p>\n
\n\t\u5982\u679c\u662f 5.5 \u4e4b\u524d\u7684\u7248\u672c\u786e\u5b9e\u4e0d\u4f1a\u8d70\u7d22\u5f15\u7684\uff0c\u5728 5.5 \u4e4b\u540e\u7684\u7248\u672c\uff0cMySQL \u505a\u4e86\u4f18\u5316\u3002MySQL \u5728 2010 \u5e74\u53d1\u5e03 5.5 \u7248\u672c\u4e2d\uff0c\u4f18\u5316\u5668\u5bf9 in \u64cd\u4f5c\u7b26\u53ef\u4ee5\u81ea\u52a8\u5b8c\u6210\u4f18\u5316\uff0c\u9488\u5bf9\u5efa\u7acb\u4e86\u7d22\u5f15\u7684\u5217\u53ef\u4ee5\u4f7f\u7528\u7d22\u5f15\uff0c\u6ca1\u6709\u7d22\u5f15\u7684\u5217\u8fd8\u662f\u4f1a\u8d70\u5168\u8868\u626b\u63cf\u3002\n<\/p>\n
\n\t\u6bd4\u5982\uff0c5.5 \u4e4b\u524d\u7684\u7248\u672c\uff08\u4ee5\u4e0b\u90fd\u662f 5.5 \u4ee5\u524d\u7684\u7248\u672c\uff09\u3002select * from a where id in (select id from b); \u8fd9\u6761 sql \u8bed\u53e5\u5b83\u7684\u6267\u884c\u8ba1\u5212\u5176\u5b9e\u5e76\u4e0d\u662f\u5148\u67e5\u8be2\u51fa b \u8868\u7684\u6240\u6709 id\uff0c\u7136\u540e\u518d\u4e0e a \u8868\u7684 id \u8fdb\u884c\u6bd4\u8f83\u3002mysql \u4f1a\u628a in \u5b50\u67e5\u8be2\u8f6c\u6362\u6210 exists \u76f8\u5173\u5b50\u67e5\u8be2\uff0c\u6240\u4ee5\u5b83\u5b9e\u9645\u7b49\u540c\u4e8e\u8fd9\u6761 sql \u8bed\u53e5\uff1aselect * from a where exists(select * from b where b.id=a.id);\n<\/p>\n
\n\t\u800c exists \u76f8\u5173\u5b50\u67e5\u8be2\u7684\u6267\u884c\u539f\u7406\u662f\uff1a\u5faa\u73af\u53d6\u51fa a \u8868\u7684\u6bcf\u4e00\u6761\u8bb0\u5f55\u4e0e b \u8868\u8fdb\u884c\u6bd4\u8f83\uff0c\u6bd4\u8f83\u7684\u6761\u4ef6\u662f a.id=b.id\u3002\u770b a \u8868\u7684\u6bcf\u6761\u8bb0\u5f55\u7684 id \u662f\u5426\u5728 b \u8868\u5b58\u5728\uff0c\u5982\u679c\u5b58\u5728\u5c31\u884c\u8fd4\u56de a \u8868\u7684\u8fd9\u6761\u8bb0\u5f55\u3002\n<\/p>\n
\n\t\u5173\u4e8e exists \u7684\u95ee\u9898\uff0c\u6211\u4eec\u4ee5\u540e\u62bd\u65f6\u95f4\u518d\u8bf4\u3002\n<\/p>\n
\n\t\u4e92\u8054\u7f51\u4e0a\u7684\u4fe1\u606f\u592a\u8fc7\u5e7f\u6cdb\uff0c\u4f46\u8fd9\u4e0d\u5e94\u8be5\u6210\u4e3a\u6211\u4eec\u6389\u4ee5\u8f7b\u5fc3\u7684\u501f\u53e3\uff0c\u62b1\u7740\u5b58\u7591\u6c42\u662f\u7684\u7cbe\u795e\u8fdb\u884c\u7504\u522b\uff0c\u4efb\u4f55\u4fe1\u606f\u53ea\u6709\u5728\u6211\u4eec\u5b9e\u8df5\u9a8c\u8bc1\u540e\u65b9\u53ef\u5168\u4fe1\uff0c\u7528\u5728\u751f\u4ea7\u5f00\u53d1\u4e0a\u7684\u77e5\u8bc6\uff0c\u4e0d\u5bb9\u6709\u5931\uff01\n<\/p>\n
\n\t\u5c3d\u4fe1\u4e66\uff0c\u4e0d\u5982\u65e0\u4e66\uff01<\/p>\n
![\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/](\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\")
<\/p>
\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1axttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a\u4e1a\u4f59\u8349<\/a>\uff1a » MySQL \u7684 in \u67e5\u8be2\u5230\u5e95\u8d70\u4e0d\u8d70\u7d22\u5f15\uff1f<\/a><\/p>","protected":false},"excerpt":{"rendered":"\u4e3a\u4ec0\u4e48\u5199\u8fd9\u7bc7\u6587\u7ae0\u5462\uff1f\u56e0\u4e3a\u6211\u4e0d\u60f3\u8ba9\u5927\u5bb6\u5728\u9519\u8bef\u4e0b\u53bb\uff01 \u6628\u5929 CSDN \u6b63\u5728\u8fdb\u884c\u4e00\u4e2a 2018 \u5e74\u7684\u535a\u5ba2\u4e4b\u661f\u6d3b\u52a8\uff0c\u5165 […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,6],"tags":[83,580,155,918,1676],"class_list":["post-3651","post","type-post","status-publish","format-standard","hentry","category-sql","category-yyzt","tag-mysql","tag-mysql----dba","tag-sql","tag-918","tag-1676"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3651","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3651"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3651\/revisions"}],"predecessor-version":[{"id":3652,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3651\/revisions\/3652"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3651"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3651"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3651"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}