{"id":170009,"date":"2024-11-06T20:23:21","date_gmt":"2024-11-06T12:23:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/170009\/"},"modified":"2024-11-06T20:23:22","modified_gmt":"2024-11-06T12:23:22","slug":"%e5%9b%8a%e6%8b%ac%e5%b8%b8%e8%ad%98%e3%80%81%e6%8a%80%e5%b7%a7%e5%8f%8a%e5%87%bd%e6%95%b8%e7%9a%84%e8%b6%85%e7%a1%ac%e6%a0%b8sql%e8%aa%9e%e5%8f%a5%e5%a4%a7%e5%85%a8%ef%bc%8c%e7%9b%a4%e5%ae%83","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/170009\/","title":{"rendered":"\u56ca\u62ec\u5e38\u8b58\u3001\u6280\u5de7\u53ca\u51fd\u6578\u7684\u8d85\u786c\u6838SQL\u8a9e\u53e5\u5927\u5168\uff0c\u76e4\u5b83\uff01"},"content":{"rendered":"<h1 id=\"%e5%9b%8a%e6%8b%ac%e5%b8%b8%e8%ad%98%e3%80%81%e6%8a%80%e5%b7%a7%e5%8f%8a%e5%87%bd%e6%95%b8%e7%9a%84%e8%b6%85%e7%a1%ac%e6%a0%b8sql%e8%aa%9e%e5%8f%a5%e5%a4%a7%e5%85%a8%ef%bc%8c%e7%9b%a4%e5%ae%83-RENSrhgtDo\">\u56ca\u62ec\u5e38\u8b58\u3001\u6280\u5de7\u53ca\u51fd\u6578\u7684\u8d85\u786c\u6838SQL\u8a9e\u53e5\u5927\u5168\uff0c\u76e4\u5b83\uff01<\/h1>\n<p>SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u7528\u65bc\u7ba1\u7406\u548c\u64cd\u4f5c\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u7121\u8ad6\u662f\u6578\u64da\u5206\u6790\u3001\u6578\u64da\u6316\u6398\u9084\u662f\u65e5\u5e38\u7684\u6578\u64da\u7ba1\u7406\uff0cSQL\u90fd\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\u5de5\u5177\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u4e00\u4e9b\u5e38\u898b\u7684SQL\u8a9e\u53e5\u3001\u6280\u5de7\u53ca\u51fd\u6578\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u638c\u63e1\u9019\u9580\u6280\u8853\u3002<\/p>\n<h2 id=\"%e5%9f%ba%e6%9c%acsql%e8%aa%9e%e5%8f%a5-RENSrhgtDo\">\u57fa\u672cSQL\u8a9e\u53e5<\/h2>\n<p>\u5728\u5b78\u7fd2SQL\u6642\uff0c\u9996\u5148\u9700\u8981\u638c\u63e1\u4e00\u4e9b\u57fa\u672c\u7684\u8a9e\u53e5\u3002\u4ee5\u4e0b\u662f\u5e7e\u500b\u5e38\u7528\u7684SQL\u8a9e\u53e5\u793a\u4f8b\uff1a<\/p>\n<h3 id=\"1-select-%e8%aa%9e%e5%8f%a5-RENSrhgtDo\">1. SELECT \u8a9e\u53e5<\/h3>\n<pre><code>SELECT column1, column2 FROM table_name;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u7528\u65bc\u5f9e\u6307\u5b9a\u7684\u8868\u4e2d\u9078\u64c7\u7279\u5b9a\u7684\u5217\u3002\u82e5\u8981\u9078\u64c7\u6240\u6709\u5217\uff0c\u53ef\u4ee5\u4f7f\u7528\u661f\u865f\uff08*\uff09\uff1a<\/p>\n<pre><code>SELECT * FROM table_name;<\/code><\/pre>\n<h3 id=\"2-insert-%e8%aa%9e%e5%8f%a5-RENSrhgtDo\">2. INSERT \u8a9e\u53e5<\/h3>\n<pre><code>INSERT INTO table_name (column1, column2) VALUES (value1, value2);<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u7528\u65bc\u5411\u8868\u4e2d\u63d2\u5165\u65b0\u8a18\u9304\u3002<\/p>\n<h3 id=\"3-update-%e8%aa%9e%e5%8f%a5-RENSrhgtDo\">3. UPDATE \u8a9e\u53e5<\/h3>\n<pre><code>UPDATE table_name SET column1 = value1 WHERE condition;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u7528\u65bc\u66f4\u65b0\u8868\u4e2d\u73fe\u6709\u7684\u8a18\u9304\u3002<\/p>\n<h3 id=\"4-delete-%e8%aa%9e%e5%8f%a5-RENSrhgtDo\">4. DELETE \u8a9e\u53e5<\/h3>\n<pre><code>DELETE FROM table_name WHERE condition;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u7528\u65bc\u522a\u9664\u8868\u4e2d\u7684\u8a18\u9304\u3002<\/p>\n<h2 id=\"%e9%80%b2%e9%9a%8e%e6%8a%80%e5%b7%a7-RENSrhgtDo\">\u9032\u968e\u6280\u5de7<\/h2>\n<p>\u9664\u4e86\u57fa\u672c\u7684SQL\u8a9e\u53e5\uff0c\u9084\u6709\u4e00\u4e9b\u9032\u968e\u6280\u5de7\u53ef\u4ee5\u5e6b\u52a9\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u548c\u6578\u64da\u8655\u7406\u80fd\u529b\u3002<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8join-RENSrhgtDo\">1. \u4f7f\u7528JOIN<\/h3>\n<p>JOIN\u8a9e\u53e5\u7528\u65bc\u5f9e\u591a\u500b\u8868\u4e2d\u67e5\u8a62\u6578\u64da\u3002\u4ee5\u4e0b\u662fINNER JOIN\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT a.column1, b.column2 \nFROM table1 a \nINNER JOIN table2 b ON a.common_column = b.common_column;<\/code><\/pre>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%a9%a2-RENSrhgtDo\">2. \u4f7f\u7528\u5b50\u67e5\u8a62<\/h3>\n<p>\u5b50\u67e5\u8a62\u662f\u5d4c\u5957\u5728\u5176\u4ed6\u67e5\u8a62\u4e2d\u7684\u67e5\u8a62\uff0c\u53ef\u4ee5\u7528\u4f86\u9032\u884c\u66f4\u8907\u96dc\u7684\u6578\u64da\u6aa2\u7d22\uff1a<\/p>\n<pre><code>SELECT column1 \nFROM table_name \nWHERE column2 IN (SELECT column2 FROM another_table WHERE condition);<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8-RENSrhgtDo\">3. \u4f7f\u7528\u805a\u5408\u51fd\u6578<\/h3>\n<p>\u805a\u5408\u51fd\u6578\u5982COUNT\u3001SUM\u3001AVG\u7b49\u53ef\u4ee5\u7528\u4f86\u9032\u884c\u6578\u64da\u7d71\u8a08\uff1a<\/p>\n<pre><code>SELECT COUNT(*) FROM table_name WHERE condition;<\/code><\/pre>\n<h2 id=\"%e5%b8%b8%e7%94%a8%e5%87%bd%e6%95%b8-RENSrhgtDo\">\u5e38\u7528\u51fd\u6578<\/h2>\n<p>SQL\u4e2d\u6709\u8a31\u591a\u5167\u5efa\u51fd\u6578\u53ef\u4ee5\u7528\u4f86\u8655\u7406\u5b57\u7b26\u4e32\u3001\u65e5\u671f\u548c\u6578\u5b57\u7b49\u6578\u64da\u985e\u578b\u3002<\/p>\n<h3 id=\"1-%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%87%bd%e6%95%b8-RENSrhgtDo\">1. \u5b57\u7b26\u4e32\u51fd\u6578<\/h3>\n<ul>\n<li><code>UPPER(string)<\/code>\uff1a\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u5927\u5beb\u3002<\/li>\n<li><code>LOWER(string)<\/code>\uff1a\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u5c0f\u5beb\u3002<\/li>\n<li><code>LENGTH(string)<\/code>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u3002<\/li>\n<\/ul>\n<h3 id=\"2-%e6%97%a5%e6%9c%9f%e5%87%bd%e6%95%b8-RENSrhgtDo\">2. \u65e5\u671f\u51fd\u6578<\/h3>\n<ul>\n<li><code>NOW()<\/code>\uff1a\u8fd4\u56de\u7576\u524d\u65e5\u671f\u548c\u6642\u9593\u3002<\/li>\n<li><code>DATE_FORMAT(date, format)<\/code>\uff1a\u683c\u5f0f\u5316\u65e5\u671f\u3002<\/li>\n<\/ul>\n<h3 id=\"3-%e6%95%b8%e5%ad%97%e5%87%bd%e6%95%b8-RENSrhgtDo\">3. \u6578\u5b57\u51fd\u6578<\/h3>\n<ul>\n<li><code>ROUND(number, decimals)<\/code>\uff1a\u5c0d\u6578\u5b57\u9032\u884c\u56db\u6368\u4e94\u5165\u3002<\/li>\n<li><code>FLOOR(number)<\/code>\uff1a\u8fd4\u56de\u5c0f\u65bc\u6216\u7b49\u65bc\u6307\u5b9a\u6578\u5b57\u7684\u6700\u5927\u6574\u6578\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-RENSrhgtDo\">\u7e3d\u7d50<\/h2>\n<p>\u638c\u63e1SQL\u8a9e\u8a00\u7684\u57fa\u672c\u8a9e\u6cd5\u3001\u9032\u968e\u6280\u5de7\u53ca\u5e38\u7528\u51fd\u6578\uff0c\u5c0d\u65bc\u6578\u64da\u7ba1\u7406\u548c\u5206\u6790\u81f3\u95dc\u91cd\u8981\u3002\u7121\u8ad6\u662f\u958b\u767c\u8005\u9084\u662f\u6578\u64da\u5206\u6790\u5e2b\uff0c\u719f\u7df4\u4f7f\u7528SQL\u90fd\u80fd\u63d0\u9ad8\u5de5\u4f5c\u6548\u7387\uff0c\u4e26\u80fd\u66f4\u597d\u5730\u8655\u7406\u6578\u64da\u3002\u82e5\u60a8\u9700\u8981\u7a69\u5b9a\u7684\u6578\u64da\u5eab\u652f\u6301\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>\uff0c\u4ee5\u78ba\u4fdd\u60a8\u7684\u6578\u64da\u5b89\u5168\u548c\u9ad8\u6548\u904b\u884c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22\u56ca\u62ec\u5e38\u8b58\u3001\u6280\u5de7\u53ca\u51fd\u6578\u7684\u8d85\u786c\u6838SQL\u8a9e\u53e5\u5927\u5168\uff0c\u52a9\u4f60\u8f15\u9b06\u638c\u63e1\u6578\u64da\u5eab\u64cd\u4f5c\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff01<\/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-170009","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/170009","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=170009"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/170009\/revisions"}],"predecessor-version":[{"id":170010,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/170009\/revisions\/170010"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=170009"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=170009"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=170009"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}