{"id":186020,"date":"2024-11-11T02:26:20","date_gmt":"2024-11-10T18:26:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/186020\/"},"modified":"2024-11-11T02:26:21","modified_gmt":"2024-11-10T18:26:21","slug":"%e6%95%b8%e6%93%9a%e5%ba%abwhere%e8%aa%9e%e5%8f%a5%e8%a9%b3%e8%a7%a3%ef%bc%88%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84where%e8%aa%9e%e5%8f%a5%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/186020\/","title":{"rendered":"\u6578\u64da\u5eabwhere\u8a9e\u53e5\u8a73\u89e3\uff08\u6578\u64da\u5eab\u7684where\u8a9e\u53e5\uff09"},"content":{"rendered":"<h1 id=\"%e6%95%b8%e6%93%9a%e5%ba%abwhere%e8%aa%9e%e5%8f%a5%e8%a9%b3%e8%a7%a3-ZtaVEZMTzw\">\u6578\u64da\u5eabWHERE\u8a9e\u53e5\u8a73\u89e3<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u67e5\u8a62\u4e2d\uff0c<code>WHERE<\/code>\u8a9e\u53e5\u662f\u4e00\u500b\u81f3\u95dc\u91cd\u8981\u7684\u7d44\u4ef6\u3002\u5b83\u7528\u65bc\u904e\u6ffe\u67e5\u8a62\u7d50\u679c\uff0c\u78ba\u4fdd\u53ea\u8fd4\u56de\u7b26\u5408\u7279\u5b9a\u689d\u4ef6\u7684\u6578\u64da\u3002\u7121\u8ad6\u662f\u4f7f\u7528SQL\u9032\u884c\u6578\u64da\u64cd\u4f5c\uff0c\u9084\u662f\u9032\u884c\u6578\u64da\u5206\u6790\uff0c<code>WHERE<\/code>\u8a9e\u53e5\u90fd\u80fd\u5e6b\u52a9\u7528\u6236\u7cbe\u78ba\u5730\u7372\u53d6\u6240\u9700\u7684\u4fe1\u606f\u3002<\/p>\n<h2 id=\"%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-ZtaVEZMTzw\">\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p><code>WHERE<\/code>\u8a9e\u53e5\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT column1, column2, ...\nFROM table_name\nWHERE condition;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>condition<\/code>\u662f\u7528\u4f86\u6307\u5b9a\u904e\u6ffe\u689d\u4ef6\u7684\u8868\u9054\u5f0f\u3002\u53ea\u6709\u6eff\u8db3\u9019\u4e9b\u689d\u4ef6\u7684\u8a18\u9304\u624d\u6703\u88ab\u9078\u4e2d\u3002<\/p>\n<h2 id=\"%e5%b8%b8%e8%a6%8b%e7%9a%84%e6%a2%9d%e4%bb%b6%e9%81%8b%e7%ae%97%e7%ac%a6-ZtaVEZMTzw\">\u5e38\u898b\u7684\u689d\u4ef6\u904b\u7b97\u7b26<\/h2>\n<p>\u5728<code>WHERE<\/code>\u8a9e\u53e5\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u591a\u7a2e\u904b\u7b97\u7b26\u4f86\u69cb\u5efa\u689d\u4ef6\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u904b\u7b97\u7b26\uff1a<\/p>\n<ul>\n<li><code>=<\/code>\uff1a\u7b49\u65bc<\/li>\n<li><code>!=<\/code>\u6216<code><\/code>\uff1a\u4e0d\u7b49\u65bc<\/li>\n<li><code>&gt;<\/code>\uff1a\u5927\u65bc<\/li>\n<li><code>&lt;<\/code>\uff1a\u5c0f\u65bc<\/li>\n<li><code>&gt;=<\/code>\uff1a\u5927\u65bc\u6216\u7b49\u65bc<\/li>\n<li><code>&lt;=<\/code>\uff1a\u5c0f\u65bc\u6216\u7b49\u65bc<\/li>\n<li><code>LIKE<\/code>\uff1a\u7528\u65bc\u6a21\u5f0f\u5339\u914d<\/li>\n<li><code>BETWEEN<\/code>\uff1a\u7bc4\u570d\u67e5\u8a62<\/li>\n<li><code>IN<\/code>\uff1a\u6aa2\u67e5\u503c\u662f\u5426\u5728\u4e00\u7d44\u503c\u4e2d<\/li>\n<li><code>IS NULL<\/code>\uff1a\u6aa2\u67e5\u503c\u662f\u5426\u70baNULL<\/li>\n<\/ul>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%a4%ba%e4%be%8b-ZtaVEZMTzw\">\u4f7f\u7528\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528<code>WHERE<\/code>\u8a9e\u53e5\u7684\u793a\u4f8b\uff1a<\/p>\n<h3 id=\"1-%e5%9f%ba%e6%9c%ac%e6%9f%a5%e8%a9%a2-ZtaVEZMTzw\">1. \u57fa\u672c\u67e5\u8a62<\/h3>\n<pre><code>SELECT * FROM employees\nWHERE department = 'Sales';<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u5728\u201cSales\u201d\u90e8\u9580\u5de5\u4f5c\u7684\u54e1\u5de5\u3002<\/p>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8%e4%b8%8d%e7%ad%89%e6%96%bc%e9%81%8b%e7%ae%97%e7%ac%a6-ZtaVEZMTzw\">2. \u4f7f\u7528\u4e0d\u7b49\u65bc\u904b\u7b97\u7b26<\/h3>\n<pre><code>SELECT * FROM products\nWHERE price != 0;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u50f9\u683c\u4e0d\u70ba\u96f6\u7684\u7522\u54c1\u3002<\/p>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8like%e9%80%b2%e8%a1%8c%e6%a8%a1%e5%bc%8f%e5%8c%b9%e9%85%8d-ZtaVEZMTzw\">3. \u4f7f\u7528LIKE\u9032\u884c\u6a21\u5f0f\u5339\u914d<\/h3>\n<pre><code>SELECT * FROM customers\nWHERE name LIKE 'A%';<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u540d\u5b57\u4ee5\u201cA\u201d\u958b\u982d\u7684\u5ba2\u6236\u3002<\/p>\n<h3 id=\"4-%e4%bd%bf%e7%94%a8between%e9%80%b2%e8%a1%8c%e7%af%84%e5%9c%8d%e6%9f%a5%e8%a9%a2-ZtaVEZMTzw\">4. \u4f7f\u7528BETWEEN\u9032\u884c\u7bc4\u570d\u67e5\u8a62<\/h3>\n<pre><code>SELECT * FROM orders\nWHERE order_date BETWEEN '2023-01-01' AND '2023-12-31';<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de2023\u5e74\u5167\u7684\u6240\u6709\u8a02\u55ae\u3002<\/p>\n<h3 id=\"5-%e4%bd%bf%e7%94%a8in%e6%aa%a2%e6%9f%a5%e5%a4%9a%e5%80%8b%e5%80%bc-ZtaVEZMTzw\">5. \u4f7f\u7528IN\u6aa2\u67e5\u591a\u500b\u503c<\/h3>\n<pre><code>SELECT * FROM students\nWHERE grade IN ('A', 'B');<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u6210\u7e3e\u70ba\u201cA\u201d\u6216\u201cB\u201d\u7684\u5b78\u751f\u3002<\/p>\n<h2 id=\"%e8%a4%87%e5%90%88%e6%a2%9d%e4%bb%b6-ZtaVEZMTzw\">\u8907\u5408\u689d\u4ef6<\/h2>\n<p>\u5728<code>WHERE<\/code>\u8a9e\u53e5\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u908f\u8f2f\u904b\u7b97\u7b26\uff08\u5982<code>AND<\/code>\u3001<code>OR<\/code>\uff09\u4f86\u7d44\u5408\u591a\u500b\u689d\u4ef6\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT * FROM employees\nWHERE department = 'Sales' AND salary &gt; 50000;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u5728\u201cSales\u201d\u90e8\u9580\u4e14\u85aa\u6c34\u9ad8\u65bc50000\u7684\u54e1\u5de5\u3002<\/p>\n<h2 id=\"%e5%b0%8f%e7%b5%90-ZtaVEZMTzw\">\u5c0f\u7d50<\/h2>\n<p>\u7e3d\u4e4b\uff0c<code>WHERE<\/code>\u8a9e\u53e5\u662f\u6578\u64da\u5eab\u67e5\u8a62\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u4e00\u90e8\u5206\u3002\u5b83\u4e0d\u50c5\u80fd\u5e6b\u52a9\u7528\u6236\u7cbe\u78ba\u5730\u904e\u6ffe\u6578\u64da\uff0c\u9084\u80fd\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u638c\u63e1<code>WHERE<\/code>\u8a9e\u53e5\u7684\u4f7f\u7528\uff0c\u5c0d\u65bc\u4efb\u4f55\u6578\u64da\u5eab\u7ba1\u7406\u548c\u6578\u64da\u5206\u6790\u7684\u5de5\u4f5c\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u6578\u64da\u5eab\u7684\u7ba1\u7406\u548c\u64cd\u4f5c\u6709\u66f4\u9ad8\u7684\u9700\u6c42\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u4f86\u63d0\u5347\u60a8\u7684\u6578\u64da\u8655\u7406\u80fd\u529b\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7684\u642d\u5efa\u9084\u662f\u65e5\u5e38\u7684\u6578\u64da\u7ba1\u7406\uff0c\u9078\u64c7\u5408\u9069\u7684\u4f3a\u670d\u5668\u90fd\u80fd\u70ba\u60a8\u7684\u696d\u52d9\u5e36\u4f86\u66f4\u5927\u7684\u4fbf\u5229\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eab\u4e2d\u7684WHERE\u8a9e\u53e5\uff0c\u4e86\u89e3\u5176\u7528\u6cd5\u3001\u7bc4\u4f8b\u53ca\u6700\u4f73\u5be6\u8e10\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\u8207\u6e96\u78ba\u6027\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-186020","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186020","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=186020"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186020\/revisions"}],"predecessor-version":[{"id":186021,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186020\/revisions\/186021"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=186020"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=186020"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=186020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}