{"id":20347,"date":"2024-01-02T04:40:24","date_gmt":"2024-01-02T04:40:24","guid":{"rendered":"https:\/\/server.hk\/blog\/20347\/"},"modified":"2024-11-14T10:40:01","modified_gmt":"2024-11-14T02:40:01","slug":"postgresql-command-create-view","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/20347\/","title":{"rendered":"PostgreSQL \u6307\u4ee4\uff1aCREATE VIEW"},"content":{"rendered":"<h1 id=\"postgresql-command-create-view-aqzIUetCGo\">PostgreSQL \u6307\u4ee4\uff1aCREATE VIEW<\/h1>\n<p>PostgreSQL \u662f\u4e00\u500b\u529f\u80fd\u5f37\u5927\u7684\u958b\u6e90\u95dc\u806f\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u5ee3\u6cdb\u7684\u529f\u80fd\u548c\u7279\u6027\u3002\u5728 PostgreSQL \u4e2d\uff0c\u4e00\u500b\u57fa\u672c\u7684\u6307\u4ee4\u662f CREATE VIEW \u6307\u4ee4\uff0c\u8a72\u6307\u4ee4\u5141\u8a31\u7528\u6236\u6839\u64da\u67e5\u8a62\u7684\u7d50\u679c\u5275\u5efa\u4e00\u500b\u865b\u64ec\u8868\u683c\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u5c07\u8a73\u7d30\u63a2\u8a0e CREATE VIEW \u6307\u4ee4\uff0c\u4e26\u4e86\u89e3\u5982\u4f55\u6709\u6548\u5730\u4f7f\u7528\u5b83\u3002<\/p>\n<h2 id=\"what-is-a-view-aqzIUetCGo\">\u4ec0\u9ebc\u662f\u8996\u5716\uff1f<\/h2>\n<p>\u5728 PostgreSQL \u4e2d\uff0c\u8996\u5716\u662f\u4e00\u500b\u865b\u64ec\u8868\u683c\uff0c\u4e26\u4e0d\u5b58\u5132\u4efb\u4f55\u81ea\u8eab\u7684\u6578\u64da\u3002\u76f8\u53cd\uff0c\u5b83\u662f\u57fa\u65bc\u5c0d\u4e00\u500b\u6216\u591a\u500b\u8868\u683c\u6216\u5176\u4ed6\u8996\u5716\u57f7\u884c\u7684\u67e5\u8a62\u7d50\u679c\u3002\u8996\u5716\u63d0\u4f9b\u4e86\u4e00\u7a2e\u7c21\u5316\u8907\u96dc\u67e5\u8a62\u3001\u5c01\u88dd\u696d\u52d9\u908f\u8f2f\u4ee5\u53ca\u5411\u7528\u6236\u5448\u73fe\u5b9a\u5236\u6578\u64da\u8996\u5716\u7684\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"creating-a-view-aqzIUetCGo\">\u5275\u5efa\u8996\u5716<\/h2>\n<p>\u4f7f\u7528 CREATE VIEW \u6307\u4ee4\u5275\u5efa\u8996\u5716\u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE VIEW view_name AS\r\nSELECT column1, column2, ...\r\nFROM table_name\r\nWHERE condition;<\/code><\/pre>\n<p>\u8b93\u6211\u5011\u5206\u89e3\u4e00\u4e0b\u8a9e\u6cd5\uff1a<\/p>\n<ul>\n<li><code>CREATE VIEW view_name<\/code>\uff1a\u9019\u6307\u5b9a\u4e86\u60a8\u60f3\u8981\u5275\u5efa\u7684\u8996\u5716\u540d\u7a31\u3002<\/li>\n<li><code>AS<\/code>\uff1a\u9019\u500b\u95dc\u9375\u5b57\u7528\u65bc\u6307\u793a\u5b9a\u7fa9\u8996\u5716\u7684\u67e5\u8a62\u958b\u59cb\u3002<\/li>\n<li><code>SELECT column1, column2, ...<\/code>\uff1a\u9019\u6307\u5b9a\u4e86\u60a8\u5e0c\u671b\u5305\u62ec\u5728\u8996\u5716\u4e2d\u7684\u5217\u3002<\/li>\n<li><code>FROM table_name<\/code>\uff1a\u9019\u6307\u5b9a\u4e86\u60a8\u5e0c\u671b\u5f9e\u4e2d\u6aa2\u7d22\u6578\u64da\u7684\u8868\u683c\u3002<\/li>\n<li><code>WHERE condition<\/code>\uff1a\u9019\u662f\u4e00\u500b\u53ef\u9078\u7684\u5b50\u53e5\uff0c\u5141\u8a31\u60a8\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u904e\u6ffe\u6578\u64da\u3002<\/li>\n<\/ul>\n<h2 id=\"example-aqzIUetCGo\">\u793a\u4f8b<\/h2>\n<p>\u8b93\u6211\u5011\u8003\u616e\u4e00\u500b\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba &#8220;employees&#8221; \u7684\u8868\u683c\uff0c\u5305\u542b &#8220;id&#8221;\u3001&#8221;name&#8221;\u3001&#8221;designation&#8221; \u548c &#8220;salary&#8221; \u7b49\u5217\u3002\u6211\u5011\u53ef\u4ee5\u5275\u5efa\u4e00\u500b\u540d\u70ba &#8220;high_salary_employees&#8221; \u7684\u8996\u5716\uff0c\u50c5\u5305\u62ec\u85aa\u6c34\u5927\u65bc $50,000 \u7684\u54e1\u5de5\uff0c\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>CREATE VIEW high_salary_employees AS\r\nSELECT id, name, designation, salary\r\nFROM employees\r\nWHERE salary &gt; 50000;<\/code><\/pre>\n<p>\u4e00\u65e6\u8996\u5716\u5275\u5efa\u5b8c\u6210\uff0c\u60a8\u53ef\u4ee5\u50cf\u67e5\u8a62\u5e38\u898f\u8868\u683c\u4e00\u6a23\u67e5\u8a62\u5b83\uff1a<\/p>\n<pre><code>SELECT * FROM high_salary_employees;<\/code><\/pre>\n<p>\u9019\u5c07\u6aa2\u7d22 &#8220;high_salary_employees&#8221; \u8996\u5716\u4e2d\u7684\u6240\u6709\u8a18\u9304\u3002<\/p>\n<h2 id=\"modifying-a-view-aqzIUetCGo\">\u4fee\u6539\u8996\u5716<\/h2>\n<p>PostgreSQL \u5141\u8a31\u60a8\u4f7f\u7528 CREATE OR REPLACE VIEW \u6307\u4ee4\u4fee\u6539\u73fe\u6709\u7684\u8996\u5716\u3002\u9019\u689d\u6307\u4ee4\u66f4\u65b0\u8996\u5716\u7684\u5b9a\u7fa9\uff0c\u800c\u4e0d\u6539\u8b8a\u5176\u540d\u7a31\u6216\u4f9d\u8cf4\u6027\u3002\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE OR REPLACE VIEW view_name AS\r\nSELECT column1, column2, ...\r\nFROM table_name\r\nWHERE condition;<\/code><\/pre>\n<p>\u901a\u904e\u4f7f\u7528 CREATE OR REPLACE VIEW \u6307\u4ee4\uff0c\u60a8\u53ef\u4ee5\u8f15\u9b06\u5730\u5c0d\u8996\u5716\u7684\u67e5\u8a62\u6216\u7d50\u69cb\u9032\u884c\u66f4\u6539\uff0c\u800c\u7121\u9700\u522a\u9664\u4e26\u91cd\u65b0\u5275\u5efa\u5b83\u3002<\/p>\n<h2 id=\"conclusion-aqzIUetCGo\">\u7d50\u8ad6<\/h2>\n<p>PostgreSQL \u7684 CREATE VIEW \u6307\u4ee4\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u5141\u8a31\u7528\u6236\u6839\u64da\u67e5\u8a62\u7684\u7d50\u679c\u5275\u5efa\u865b\u64ec\u8868\u683c\u3002\u8996\u5716\u63d0\u4f9b\u4e86\u4e00\u7a2e\u7c21\u5316\u8907\u96dc\u67e5\u8a62\u3001\u5c01\u88dd\u696d\u52d9\u908f\u8f2f\u4ee5\u53ca\u5448\u73fe\u5b9a\u5236\u6578\u64da\u8996\u5716\u7684\u65b9\u6cd5\u3002\u901a\u904e\u4e86\u89e3\u5982\u4f55\u5275\u5efa\u548c\u4fee\u6539\u8996\u5716\uff0c\u60a8\u53ef\u4ee5\u63d0\u9ad8\u8cc7\u6599\u5eab\u64cd\u4f5c\u7684\u6548\u7387\u548c\u9748\u6d3b\u6027\u3002<\/p>\n<h2 id=\"summary-aqzIUetCGo\">\u7e3d\u7d50<\/h2>\n<p>\u7e3d\u4e4b\uff0cPostgreSQL \u7684 CREATE VIEW \u6307\u4ee4\u5141\u8a31\u7528\u6236\u6839\u64da\u67e5\u8a62\u7684\u7d50\u679c\u5275\u5efa\u865b\u64ec\u8868\u683c\u3002\u8996\u5716\u63d0\u4f9b\u4e86\u4e00\u7a2e\u7c21\u5316\u8907\u96dc\u67e5\u8a62\u3001\u5c01\u88dd\u696d\u52d9\u908f\u8f2f\u4ee5\u53ca\u5448\u73fe\u5b9a\u5236\u6578\u64da\u8996\u5716\u7684\u65b9\u6cd5\u3002\u901a\u904e\u4f7f\u7528 CREATE OR REPLACE VIEW \u6307\u4ee4\uff0c\u60a8\u53ef\u4ee5\u8f15\u9b06\u4fee\u6539\u73fe\u6709\u8996\u5716\uff0c\u800c\u7121\u9700\u522a\u9664\u4e26\u91cd\u65b0\u5275\u5efa\u5b83\u3002\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc VPS \u4e3b\u6a5f\u89e3\u6c7a\u65b9\u6848\u7684\u4fe1\u606f\uff0c\u8acb\u8a2a\u554f <a href=\"https:\/\/server.hk\">Server.HK<\/a>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>PostgreSQL \u6307\u4ee4\uff1aCR&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4924],"tags":[],"class_list":["post-20347","post","type-post","status-publish","format-standard","hentry","category-setup-tutorials"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20347","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=20347"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20347\/revisions"}],"predecessor-version":[{"id":24409,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20347\/revisions\/24409"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=20347"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=20347"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=20347"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}