{"id":77698,"date":"2024-10-16T11:02:19","date_gmt":"2024-10-16T03:02:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/77698\/"},"modified":"2024-10-16T11:02:19","modified_gmt":"2024-10-16T03:02:19","slug":"mysql%e6%8c%87%e4%bb%a4-as%ef%bc%88%e5%88%a5%e5%90%8d%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/77698\/","title":{"rendered":"MySQL\u6307\u4ee4: AS\uff08\u5225\u540d\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-as%ef%bc%88%e5%88%a5%e5%90%8d%ef%bc%89-TmVFgmdGSx\">MySQL\u6307\u4ee4: AS\uff08\u5225\u540d\uff09<\/h1>\n<p>\u5728\u4f7f\u7528MySQL\u9032\u884c\u6578\u64da\u5eab\u67e5\u8a62\u6642\uff0c\u7d93\u5e38\u9700\u8981\u5c0d\u67e5\u8a62\u7d50\u679c\u9032\u884c\u683c\u5f0f\u5316\u6216\u7c21\u5316\uff0c\u4ee5\u4fbf\u66f4\u6e05\u6670\u5730\u5c55\u793a\u6578\u64da\u3002\u9019\u6642\uff0c<code>AS<\/code>\u6307\u4ee4\u4fbf\u6210\u70ba\u4e86\u4e00\u500b\u975e\u5e38\u6709\u7528\u7684\u5de5\u5177\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e<code>AS<\/code>\u6307\u4ee4\u7684\u7528\u6cd5\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u91cd\u8981\u6027\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afas%e6%8c%87%e4%bb%a4%ef%bc%9f-TmVFgmdGSx\">\u4ec0\u9ebc\u662fAS\u6307\u4ee4\uff1f<\/h2>\n<p><code>AS<\/code>\u6307\u4ee4\u7528\u65bc\u70ba\u67e5\u8a62\u7d50\u679c\u4e2d\u7684\u5217\u6216\u8868\u6307\u5b9a\u5225\u540d\u3002\u9019\u6a23\u505a\u7684\u597d\u8655\u5728\u65bc\u53ef\u4ee5\u4f7f\u67e5\u8a62\u7d50\u679c\u66f4\u5177\u53ef\u8b80\u6027\uff0c\u4e26\u4e14\u5728\u9032\u884c\u6578\u64da\u8655\u7406\u6642\uff0c\u80fd\u5920\u66f4\u65b9\u4fbf\u5730\u5f15\u7528\u9019\u4e9b\u5217\u6216\u8868\u3002<\/p>\n<h2 id=\"as%e6%8c%87%e4%bb%a4%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-TmVFgmdGSx\">AS\u6307\u4ee4\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p>\u4f7f\u7528<code>AS<\/code>\u6307\u4ee4\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT column_name AS alias_name\nFROM table_name;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>column_name<\/code>\u662f\u4f60\u60f3\u8981\u67e5\u8a62\u7684\u5217\u540d\uff0c\u800c<code>alias_name<\/code>\u5247\u662f\u4f60\u70ba\u8a72\u5217\u6307\u5b9a\u7684\u5225\u540d\u3002<\/p>\n<h2 id=\"as%e6%8c%87%e4%bb%a4%e7%9a%84%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8-TmVFgmdGSx\">AS\u6307\u4ee4\u7684\u5be6\u969b\u61c9\u7528<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528<code>AS<\/code>\u6307\u4ee4\u7684\u5be6\u969b\u4f8b\u5b50\uff1a<\/p>\n<h3 id=\"%e4%be%8b%e5%ad%901%ef%bc%9a%e7%b0%a1%e5%8c%96%e5%88%97%e5%90%8d-TmVFgmdGSx\">\u4f8b\u5b501\uff1a\u7c21\u5316\u5217\u540d<\/h3>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba<code>employees<\/code>\u7684\u8868\uff0c\u5305\u542b\u4ee5\u4e0b\u5217\uff1a<code>first_name<\/code>\u3001<code>last_name<\/code>\u548c<code>salary<\/code>\u3002\u5982\u679c\u6211\u5011\u60f3\u8981\u67e5\u8a62\u54e1\u5de5\u7684\u5168\u540d\u548c\u85aa\u6c34\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT first_name AS \u540d\u5b57, last_name AS \u59d3\u6c0f, salary AS \u85aa\u6c34\nFROM employees;<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u67e5\u8a62\u7d50\u679c\u5c07\u986f\u793a\u70ba\u201c\u540d\u5b57\u201d\u3001\u201c\u59d3\u6c0f\u201d\u548c\u201c\u85aa\u6c34\u201d\uff0c\u4f7f\u5f97\u7d50\u679c\u66f4\u52a0\u76f4\u89c0\u3002<\/p>\n<h3 id=\"%e4%be%8b%e5%ad%902%ef%bc%9a%e4%bd%bf%e7%94%a8%e5%88%a5%e5%90%8d%e9%80%b2%e8%a1%8c%e8%a8%88%e7%ae%97-TmVFgmdGSx\">\u4f8b\u5b502\uff1a\u4f7f\u7528\u5225\u540d\u9032\u884c\u8a08\u7b97<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u6211\u5011\u53ef\u80fd\u9700\u8981\u5c0d\u6578\u64da\u9032\u884c\u8a08\u7b97\u4e26\u7d66\u7d50\u679c\u6307\u5b9a\u5225\u540d\u3002\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u60f3\u8981\u8a08\u7b97\u6bcf\u4f4d\u54e1\u5de5\u7684\u5e74\u85aa\uff08\u5047\u8a2d\u85aa\u6c34\u662f\u6708\u85aa\uff09\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT first_name AS \u540d\u5b57, last_name AS \u59d3\u6c0f, salary * 12 AS \u5e74\u85aa\nFROM employees;<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u4f4d\u54e1\u5de5\u7684\u540d\u5b57\u3001\u59d3\u6c0f\u548c\u5e74\u85aa\uff0c\u4e26\u4e14\u5e74\u85aa\u7684\u5217\u540d\u5c07\u986f\u793a\u70ba\u201c\u5e74\u85aa\u201d\u3002<\/p>\n<h3 id=\"%e4%be%8b%e5%ad%903%ef%bc%9a%e7%82%ba%e8%a1%a8%e6%8c%87%e5%ae%9a%e5%88%a5%e5%90%8d-TmVFgmdGSx\">\u4f8b\u5b503\uff1a\u70ba\u8868\u6307\u5b9a\u5225\u540d<\/h3>\n<p>\u9664\u4e86\u70ba\u5217\u6307\u5b9a\u5225\u540d\u5916\uff0c\u6211\u5011\u4e5f\u53ef\u4ee5\u70ba\u8868\u6307\u5b9a\u5225\u540d\u3002\u9019\u5728\u9032\u884c\u591a\u8868\u67e5\u8a62\u6642\u7279\u5225\u6709\u7528\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT e.first_name AS \u540d\u5b57, e.last_name AS \u59d3\u6c0f\nFROM employees AS e\nJOIN departments AS d ON e.department_id = d.id;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u70ba<code>employees<\/code>\u8868\u6307\u5b9a\u4e86\u5225\u540d<code>e<\/code>\uff0c\u9019\u6a23\u5728\u67e5\u8a62\u4e2d\u5f15\u7528\u6642\u6703\u66f4\u52a0\u7c21\u6f54\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-TmVFgmdGSx\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u4f7f\u7528<code>AS<\/code>\u6307\u4ee4\u6642\uff0c\u6709\u5e7e\u9ede\u9700\u8981\u6ce8\u610f\uff1a<\/p>\n<ul>\n<li>\u5225\u540d\u4e0d\u9700\u8981\u4f7f\u7528<code>AS<\/code>\u95dc\u9375\u5b57\uff0c\u53ef\u4ee5\u76f4\u63a5\u5beb\u6210<code>column_name alias_name<\/code>\u3002<\/li>\n<li>\u5982\u679c\u5225\u540d\u5305\u542b\u7a7a\u683c\u6216\u7279\u6b8a\u5b57\u7b26\uff0c\u5247\u9700\u8981\u4f7f\u7528\u5f15\u865f\u5c07\u5176\u62ec\u8d77\u4f86\uff0c\u4f8b\u5982\uff1a<code>SELECT column_name AS '\u5225\u540d'<\/code>\u3002<\/li>\n<li>\u5225\u540d\u7684\u547d\u540d\u61c9\u8a72\u7c21\u6f54\u660e\u4e86\uff0c\u4fbf\u65bc\u7406\u89e3\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-TmVFgmdGSx\">\u7e3d\u7d50<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c<code>AS<\/code>\u6307\u4ee4\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u66f4\u597d\u5730\u7d44\u7e54\u548c\u5c55\u793a\u67e5\u8a62\u7d50\u679c\u3002\u901a\u904e\u70ba\u5217\u548c\u8868\u6307\u5b9a\u5225\u540d\uff0c\u7528\u6236\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u7684\u53ef\u8b80\u6027\u548c\u53ef\u7dad\u8b77\u6027\u3002\u7121\u8ad6\u662f\u5728\u65e5\u5e38\u7684\u6578\u64da\u67e5\u8a62\u9084\u662f\u8907\u96dc\u7684\u6578\u64da\u5206\u6790\u4e2d\uff0c<code>AS<\/code>\u6307\u4ee4\u90fd\u80fd\u767c\u63ee\u91cd\u8981\u4f5c\u7528\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u6216\u5176\u4ed6\u76f8\u95dc\u6280\u8853\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4e86\u89e3\u66f4\u591a\u8cc7\u8a0a\uff0c\u7279\u5225\u662f\u6211\u5011\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u89e3\u6c7a\u65b9\u6848\uff0c\u80fd\u5920\u70ba\u60a8\u7684\u696d\u52d9\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u4e2d\u7684AS\u6307\u4ee4\uff0c\u5b78\u7fd2\u5982\u4f55\u70ba\u67e5\u8a62\u7d50\u679c\u4e2d\u7684\u5217\u6216\u8868\u6307\u5b9a\u5225\u540d\uff0c\u63d0\u5347\u6578\u64da\u53ef\u8b80\u6027\u8207\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-77698","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77698","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=77698"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77698\/revisions"}],"predecessor-version":[{"id":77699,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77698\/revisions\/77699"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=77698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=77698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=77698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}