{"id":154623,"date":"2024-11-02T17:21:21","date_gmt":"2024-11-02T09:21:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/154623\/"},"modified":"2024-11-02T17:21:22","modified_gmt":"2024-11-02T09:21:22","slug":"%e5%b0%8d-sql-%e8%a1%a8%e7%b5%90%e6%a7%8b%e7%9a%84%e6%9f%a5%e8%a9%a2","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/154623\/","title":{"rendered":"\u5c0d SQL \u8868\u7d50\u69cb\u7684\u67e5\u8a62"},"content":{"rendered":"<h1 id=\"%e5%b0%8d-sql-%e8%a1%a8%e7%b5%90%e6%a7%8b%e7%9a%84%e6%9f%a5%e8%a9%a2-RPcNyzNUwr\">\u5c0d SQL \u8868\u7d50\u69cb\u7684\u67e5\u8a62<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u4e00\u7a2e\u7528\u65bc\u67e5\u8a62\u548c\u64cd\u4f5c\u6578\u64da\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u5c0d\u65bc\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u4f86\u8aaa\uff0c\u4e86\u89e3\u5982\u4f55\u67e5\u8a62 SQL \u8868\u7684\u7d50\u69cb\u662f\u975e\u5e38\u91cd\u8981\u7684\uff0c\u56e0\u70ba\u9019\u53ef\u4ee5\u5e6b\u52a9\u4ed6\u5011\u66f4\u597d\u5730\u7406\u89e3\u6578\u64da\u5eab\u7684\u8a2d\u8a08\u548c\u6578\u64da\u7684\u7d44\u7e54\u65b9\u5f0f\u3002<\/p>\n<h2 id=\"sql-%e8%a1%a8%e7%b5%90%e6%a7%8b%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-RPcNyzNUwr\">SQL \u8868\u7d50\u69cb\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>SQL \u8868\u662f\u6578\u64da\u5eab\u4e2d\u7684\u57fa\u672c\u7d44\u7e54\u55ae\u4f4d\uff0c\u901a\u5e38\u7531\u884c\u548c\u5217\u7d44\u6210\u3002\u6bcf\u4e00\u884c\u4ee3\u8868\u4e00\u689d\u8a18\u9304\uff0c\u800c\u6bcf\u4e00\u5217\u5247\u4ee3\u8868\u4e00\u500b\u5c6c\u6027\u6216\u5b57\u6bb5\u3002\u8868\u7684\u7d50\u69cb\u5305\u62ec\u8868\u540d\u3001\u5b57\u6bb5\u540d\u3001\u6578\u64da\u985e\u578b\u3001\u7d04\u675f\u689d\u4ef6\u7b49\u4fe1\u606f\u3002\u4e86\u89e3\u9019\u4e9b\u7d50\u69cb\u5c0d\u65bc\u6709\u6548\u5730\u9032\u884c\u6578\u64da\u64cd\u4f5c\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e8%a9%a2%e8%a1%a8%e7%b5%90%e6%a7%8b%e7%9a%84%e6%96%b9%e6%b3%95-RPcNyzNUwr\">\u67e5\u8a62\u8868\u7d50\u69cb\u7684\u65b9\u6cd5<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u6709\u5e7e\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u67e5\u8a62\u8868\u7684\u7d50\u69cb\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8-describe-%e8%aa%9e%e5%8f%a5-RPcNyzNUwr\">1. \u4f7f\u7528 DESCRIBE \u8a9e\u53e5<\/h3>\n<p>\u6700\u5e38\u898b\u7684\u67e5\u8a62\u8868\u7d50\u69cb\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 <code>DESCRIBE<\/code> \u8a9e\u53e5\u3002\u9019\u500b\u8a9e\u53e5\u53ef\u4ee5\u986f\u793a\u8868\u7684\u6240\u6709\u5217\u53ca\u5176\u6578\u64da\u985e\u578b\u3001\u662f\u5426\u53ef\u4ee5\u70ba\u7a7a\u3001\u9375\u985e\u578b\u7b49\u4fe1\u606f\u3002<\/p>\n<pre><code>DESCRIBE \u8868\u540d;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>users<\/code> \u7684\u8868\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\u4f86\u67e5\u8a62\u5176\u7d50\u69cb\uff1a<\/p>\n<pre><code>DESCRIBE users;<\/code><\/pre>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8-show-columns-%e8%aa%9e%e5%8f%a5-RPcNyzNUwr\">2. \u4f7f\u7528 SHOW COLUMNS \u8a9e\u53e5<\/h3>\n<p>\u53e6\u4e00\u7a2e\u67e5\u8a62\u8868\u7d50\u69cb\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 <code>SHOW COLUMNS<\/code> \u8a9e\u53e5\u3002\u9019\u500b\u8a9e\u53e5\u7684\u529f\u80fd\u8207 <code>DESCRIBE<\/code> \u985e\u4f3c\uff0c\u4f46\u5b83\u63d0\u4f9b\u7684\u683c\u5f0f\u7565\u6709\u4e0d\u540c\u3002<\/p>\n<pre><code>SHOW COLUMNS FROM \u8868\u540d;<\/code><\/pre>\n<p>\u4f8b\u5982\uff1a<\/p>\n<pre><code>SHOW COLUMNS FROM users;<\/code><\/pre>\n<h3 id=\"3-%e6%9f%a5%e8%a9%a2-information_schema-RPcNyzNUwr\">3. \u67e5\u8a62 INFORMATION_SCHEMA<\/h3>\n<p>\u5c0d\u65bc\u66f4\u8907\u96dc\u7684\u67e5\u8a62\u9700\u6c42\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>INFORMATION_SCHEMA<\/code> \u6578\u64da\u5eab\u3002\u9019\u662f\u4e00\u500b\u865b\u64ec\u6578\u64da\u5eab\uff0c\u5305\u542b\u4e86\u6240\u6709\u6578\u64da\u5eab\u7684\u5143\u6578\u64da\u3002\u53ef\u4ee5\u901a\u904e\u67e5\u8a62 <code>INFORMATION_SCHEMA.TABLES<\/code> \u548c <code>INFORMATION_SCHEMA.COLUMNS<\/code> \u4f86\u7372\u53d6\u8868\u7684\u8a73\u7d30\u4fe1\u606f\u3002<\/p>\n<pre><code>SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'users';<\/code><\/pre>\n<h2 id=\"%e6%9f%a5%e8%a9%a2%e7%b5%90%e6%9e%9c%e7%9a%84%e8%a7%a3%e8%ae%80-RPcNyzNUwr\">\u67e5\u8a62\u7d50\u679c\u7684\u89e3\u8b80<\/h2>\n<p>\u67e5\u8a62\u8868\u7d50\u69cb\u5f8c\uff0c\u7d50\u679c\u901a\u5e38\u6703\u986f\u793a\u4ee5\u4e0b\u5e7e\u500b\u91cd\u8981\u4fe1\u606f\uff1a<\/p>\n<ul>\n<li><strong>Field\uff1a<\/strong> \u5217\u7684\u540d\u7a31\u3002<\/li>\n<li><strong>Type\uff1a<\/strong> \u5217\u7684\u6578\u64da\u985e\u578b\uff0c\u4f8b\u5982 <code>INT<\/code>\u3001<code>VARCHAR<\/code> \u7b49\u3002<\/li>\n<li><strong>Null\uff1a<\/strong> \u662f\u5426\u5141\u8a31\u8a72\u5217\u70ba\u7a7a\u3002<\/li>\n<li><strong>Key\uff1a<\/strong> \u662f\u5426\u70ba\u4e3b\u9375\u6216\u7d22\u5f15\u3002<\/li>\n<li><strong>Default\uff1a<\/strong> \u5217\u7684\u9ed8\u8a8d\u503c\u3002<\/li>\n<li><strong>Extra\uff1a<\/strong> \u5176\u4ed6\u4fe1\u606f\uff0c\u4f8b\u5982\u81ea\u589e\u5c6c\u6027\u3002<\/li>\n<\/ul>\n<p>\u7406\u89e3\u9019\u4e9b\u4fe1\u606f\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5728\u9032\u884c\u6578\u64da\u64cd\u4f5c\u6642\u505a\u51fa\u66f4\u660e\u667a\u7684\u6c7a\u7b56\uff0c\u4e26\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-RPcNyzNUwr\">\u7d50\u8ad6<\/h2>\n<p>\u67e5\u8a62 SQL \u8868\u7684\u7d50\u69cb\u662f\u6578\u64da\u5eab\u7ba1\u7406\u548c\u958b\u767c\u4e2d\u7684\u4e00\u9805\u57fa\u672c\u6280\u80fd\u3002\u7121\u8ad6\u662f\u4f7f\u7528 <code>DESCRIBE<\/code>\u3001<code>SHOW COLUMNS<\/code> \u9084\u662f\u67e5\u8a62 <code>INFORMATION_SCHEMA<\/code>\uff0c\u638c\u63e1\u9019\u4e9b\u65b9\u6cd5\u90fd\u80fd\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u5eab\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u7a69\u5b9a\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u67e5\u8a62 SQL \u8868\u7d50\u69cb\uff0c\u7372\u53d6\u6b04\u4f4d\u8cc7\u8a0a\u3001\u6578\u64da\u985e\u578b\u53ca\u7d04\u675f\u689d\u4ef6\uff0c\u63d0\u5347\u6578\u64da\u5eab\u7ba1\u7406\u6548\u7387\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-154623","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/154623","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=154623"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/154623\/revisions"}],"predecessor-version":[{"id":154624,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/154623\/revisions\/154624"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=154623"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=154623"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=154623"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}