{"id":75764,"date":"2024-10-16T01:01:15","date_gmt":"2024-10-15T17:01:15","guid":{"rendered":"https:\/\/server.hk\/cnblog\/75764\/"},"modified":"2024-10-16T01:01:16","modified_gmt":"2024-10-15T17:01:16","slug":"mysql-%e9%81%8d%e6%ad%b7%e6%95%b8%e6%93%9a%e8%a1%a8%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/75764\/","title":{"rendered":"MySQL \u904d\u6b77\u6578\u64da\u8868\u7684\u65b9\u6cd5"},"content":{"rendered":"<h1 id=\"mysql-%e9%81%8d%e6%ad%b7%e6%95%b8%e6%93%9a%e8%a1%a8%e7%9a%84%e6%96%b9%e6%b3%95-iEUyprZlnW\">MySQL \u904d\u6b77\u6578\u64da\u8868\u7684\u65b9\u6cd5<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cMySQL \u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u958b\u6e90\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u3002\u904d\u6b77\u6578\u64da\u8868\u662f\u6578\u64da\u5eab\u64cd\u4f5c\u4e2d\u4e00\u500b\u57fa\u672c\u800c\u91cd\u8981\u7684\u4efb\u52d9\uff0c\u7121\u8ad6\u662f\u7528\u65bc\u6578\u64da\u67e5\u8a62\u3001\u5831\u544a\u751f\u6210\u9084\u662f\u6578\u64da\u5206\u6790\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u5728 MySQL \u4e2d\u904d\u6b77\u6578\u64da\u8868\u7684\u65b9\u6cd5\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8-select-%e8%aa%9e%e5%8f%a5-iEUyprZlnW\">1. \u4f7f\u7528 SELECT \u8a9e\u53e5<\/h2>\n<p>\u6700\u57fa\u672c\u7684\u904d\u6b77\u6578\u64da\u8868\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 <code>SELECT<\/code> \u8a9e\u53e5\u3002\u9019\u500b\u8a9e\u53e5\u53ef\u4ee5\u7528\u4f86\u67e5\u8a62\u6574\u500b\u8868\u6216\u7279\u5b9a\u7684\u5217\u3002<\/p>\n<pre><code>SELECT * FROM \u8868\u540d;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u8fd4\u56de\u8868\u4e2d\u6240\u6709\u7684\u884c\u548c\u5217\u3002\u5982\u679c\u53ea\u60f3\u67e5\u8a62\u7279\u5b9a\u7684\u5217\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT \u52171, \u52172 FROM \u8868\u540d;<\/code><\/pre>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8-where-%e5%ad%90%e5%8f%a5%e9%81%8e%e6%bf%be%e6%95%b8%e6%93%9a-iEUyprZlnW\">2. \u4f7f\u7528 WHERE \u5b50\u53e5\u904e\u6ffe\u6578\u64da<\/h2>\n<p>\u5728\u904d\u6b77\u6578\u64da\u8868\u6642\uff0c\u7d93\u5e38\u9700\u8981\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u904e\u6ffe\u6578\u64da\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528 <code>WHERE<\/code> \u5b50\u53e5\u3002<\/p>\n<pre><code>SELECT * FROM \u8868\u540d WHERE \u689d\u4ef6;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u60f3\u67e5\u8a62\u5e74\u9f61\u5927\u65bc 30 \u7684\u7528\u6236\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT * FROM \u7528\u6236 WHERE \u5e74\u9f61 &gt; 30;<\/code><\/pre>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8-order-by-%e6%8e%92%e5%ba%8f%e7%b5%90%e6%9e%9c-iEUyprZlnW\">3. \u4f7f\u7528 ORDER BY \u6392\u5e8f\u7d50\u679c<\/h2>\n<p>\u6709\u6642\u5019\uff0c\u904d\u6b77\u7684\u7d50\u679c\u9700\u8981\u6309\u7167\u67d0\u500b\u5217\u9032\u884c\u6392\u5e8f\u3002\u9019\u53ef\u4ee5\u901a\u904e <code>ORDER BY<\/code> \u5b50\u53e5\u4f86\u5be6\u73fe\u3002<\/p>\n<pre><code>SELECT * FROM \u8868\u540d ORDER BY \u5217\u540d ASC|DESC;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u6309\u5e74\u9f61\u5347\u5e8f\u6392\u5217\u7528\u6236\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT * FROM \u7528\u6236 ORDER BY \u5e74\u9f61 ASC;<\/code><\/pre>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8-limit-%e9%99%90%e5%88%b6%e7%b5%90%e6%9e%9c%e6%95%b8%e9%87%8f-iEUyprZlnW\">4. \u4f7f\u7528 LIMIT \u9650\u5236\u7d50\u679c\u6578\u91cf<\/h2>\n<p>\u5728\u8655\u7406\u5927\u578b\u6578\u64da\u8868\u6642\uff0c\u53ef\u80fd\u53ea\u9700\u8981\u67e5\u770b\u90e8\u5206\u6578\u64da\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528 <code>LIMIT<\/code> \u5b50\u53e5\u4f86\u9650\u5236\u8fd4\u56de\u7684\u884c\u6578\u3002<\/p>\n<pre><code>SELECT * FROM \u8868\u540d LIMIT \u6578\u91cf;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u82e5\u53ea\u60f3\u67e5\u770b\u524d 10 \u689d\u8a18\u9304\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT * FROM \u7528\u6236 LIMIT 10;<\/code><\/pre>\n<h2 id=\"5-%e4%bd%bf%e7%94%a8-join-%e9%80%a3%e6%8e%a5%e5%a4%9a%e5%80%8b%e8%a1%a8-iEUyprZlnW\">5. \u4f7f\u7528 JOIN \u9023\u63a5\u591a\u500b\u8868<\/h2>\n<p>\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u6578\u64da\u901a\u5e38\u5206\u4f48\u5728\u591a\u500b\u8868\u4e2d\u3002\u4f7f\u7528 <code>JOIN<\/code> \u8a9e\u53e5\u53ef\u4ee5\u5c07\u9019\u4e9b\u8868\u9023\u63a5\u8d77\u4f86\uff0c\u5f9e\u800c\u904d\u6b77\u76f8\u95dc\u6578\u64da\u3002<\/p>\n<pre><code>SELECT \u88681.\u5217\u540d, \u88682.\u5217\u540d FROM \u88681 JOIN \u88682 ON \u88681.\u5171\u540c\u5217 = \u88682.\u5171\u540c\u5217;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u67e5\u8a62\u7528\u6236\u53ca\u5176\u8a02\u55ae\u4fe1\u606f\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT \u7528\u6236.\u59d3\u540d, \u8a02\u55ae.\u91d1\u984d FROM \u7528\u6236 JOIN \u8a02\u55ae ON \u7528\u6236.id = \u8a02\u55ae.\u7528\u6236_id;<\/code><\/pre>\n<h2 id=\"6-%e4%bd%bf%e7%94%a8-%e6%b8%b8%e6%a8%99%e9%81%8d%e6%ad%b7%e6%95%b8%e6%93%9a-iEUyprZlnW\">6. \u4f7f\u7528 \u6e38\u6a19\u904d\u6b77\u6578\u64da<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u53ef\u80fd\u9700\u8981\u9010\u884c\u8655\u7406\u67e5\u8a62\u7d50\u679c\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528\u6e38\u6a19\uff08Cursor\uff09\u3002\u6e38\u6a19\u5141\u8a31\u9010\u884c\u904d\u6b77\u67e5\u8a62\u7d50\u679c\u96c6\u3002<\/p>\n<pre><code>\nDECLARE \u6e38\u6a19\u540d CURSOR FOR SELECT * FROM \u8868\u540d;\nOPEN \u6e38\u6a19\u540d;\nFETCH NEXT FROM \u6e38\u6a19\u540d INTO \u8b8a\u91cf1, \u8b8a\u91cf2;\nCLOSE \u6e38\u6a19\u540d;\nDEALLOCATE \u6e38\u6a19\u540d;\n<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-iEUyprZlnW\">\u7e3d\u7d50<\/h2>\n<p>MySQL \u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u904d\u6b77\u6578\u64da\u8868\uff0c\u5f9e\u57fa\u672c\u7684 <code>SELECT<\/code> \u8a9e\u53e5\u5230\u66f4\u8907\u96dc\u7684 <code>JOIN<\/code> \u548c\u6e38\u6a19\u64cd\u4f5c\u3002\u6839\u64da\u5177\u9ad4\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u6709\u6548\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u5b58\u5132\u548c\u7ba1\u7406\u7684\u7528\u6236\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u985e\u578b\u7684 <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a>\uff0c\u90fd\u80fd\u70ba\u60a8\u7684\u6578\u64da\u5eab\u64cd\u4f5c\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 MySQL \u904d\u6b77\u6578\u64da\u8868\u7684\u6709\u6548\u65b9\u6cd5\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\uff0c\u7c21\u5316\u67e5\u8a62\u64cd\u4f5c\uff0c\u52a9\u529b\u6578\u64da\u7ba1\u7406\u8207\u5206\u6790\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-75764","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75764","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=75764"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75764\/revisions"}],"predecessor-version":[{"id":75765,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75764\/revisions\/75765"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=75764"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=75764"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=75764"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}