{"id":153383,"date":"2024-11-02T06:59:18","date_gmt":"2024-11-01T22:59:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/153383\/"},"modified":"2024-11-02T06:59:19","modified_gmt":"2024-11-01T22:59:19","slug":"%e5%be%9e%e9%a0%ad%e5%88%b0%e5%b0%be%e5%ad%b8%e7%bf%92%ef%bc%9apg-%e6%95%b8%e6%93%9a%e5%ba%ab%e5%a6%82%e4%bd%95%e9%ab%98%e6%95%88%e8%bd%89%e6%8f%9b%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-pg-%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/153383\/","title":{"rendered":"\u5f9e\u982d\u5230\u5c3e\u5b78\u7fd2\uff1aPG \u6578\u64da\u5eab\u5982\u4f55\u9ad8\u6548\u8f49\u63db\u6578\u64da\u985e\u578b (PG \u6578\u64da\u5eab\u5982\u4f55\u8f49\u5316\u6578\u64da\u985e\u578b)"},"content":{"rendered":"<h1 id=\"%e5%be%9e%e9%a0%ad%e5%88%b0%e5%b0%be%e5%ad%b8%e7%bf%92%ef%bc%9apg-%e6%95%b8%e6%93%9a%e5%ba%ab%e5%a6%82%e4%bd%95%e9%ab%98%e6%95%88%e8%bd%89%e6%8f%9b%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-BmutjyLKVh\">\u5f9e\u982d\u5230\u5c3e\u5b78\u7fd2\uff1aPG \u6578\u64da\u5eab\u5982\u4f55\u9ad8\u6548\u8f49\u63db\u6578\u64da\u985e\u578b<\/h1>\n<p>\u5728\u73fe\u4ee3\u6578\u64da\u7ba1\u7406\u4e2d\uff0c\u6578\u64da\u985e\u578b\u7684\u8f49\u63db\u662f\u4e00\u500b\u4e0d\u53ef\u6216\u7f3a\u7684\u904e\u7a0b\u3002PostgreSQL\uff08PG\uff09\u4f5c\u70ba\u4e00\u500b\u5f37\u5927\u7684\u958b\u6e90\u6578\u64da\u5eab\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u5de5\u5177\u548c\u65b9\u6cd5\u4f86\u9ad8\u6548\u5730\u8f49\u63db\u6578\u64da\u985e\u578b\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0ePG\u6578\u64da\u5eab\u4e2d\u6578\u64da\u985e\u578b\u8f49\u63db\u7684\u57fa\u672c\u6982\u5ff5\u3001\u65b9\u6cd5\u53ca\u5176\u6700\u4f73\u5be6\u8e10\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-BmutjyLKVh\">\u6578\u64da\u985e\u578b\u8f49\u63db\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u6578\u64da\u985e\u578b\u8f49\u63db\u662f\u6307\u5c07\u4e00\u7a2e\u6578\u64da\u985e\u578b\u7684\u6578\u64da\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\u6578\u64da\u985e\u578b\u7684\u904e\u7a0b\u3002\u5728PG\u4e2d\uff0c\u6578\u64da\u985e\u578b\u8f49\u63db\u53ef\u4ee5\u5206\u70ba\u96b1\u5f0f\u8f49\u63db\u548c\u986f\u5f0f\u8f49\u63db\u3002\u96b1\u5f0f\u8f49\u63db\u662f\u6307PG\u81ea\u52d5\u9032\u884c\u7684\u8f49\u63db\uff0c\u800c\u986f\u5f0f\u8f49\u63db\u5247\u9700\u8981\u7528\u6236\u4f7f\u7528\u7279\u5b9a\u7684\u51fd\u6578\u6216\u8a9e\u6cd5\u4f86\u9032\u884c\u3002<\/p>\n<h3 id=\"%e9%9a%b1%e5%bc%8f%e8%bd%89%e6%8f%9b-BmutjyLKVh\">\u96b1\u5f0f\u8f49\u63db<\/h3>\n<p>\u96b1\u5f0f\u8f49\u63db\u901a\u5e38\u5728\u6578\u64da\u985e\u578b\u4e0d\u5339\u914d\u7684\u60c5\u6cc1\u4e0b\u81ea\u52d5\u767c\u751f\u3002\u4f8b\u5982\uff0c\u7576\u5c07\u6574\u6578\u8207\u6d6e\u9ede\u6578\u9032\u884c\u904b\u7b97\u6642\uff0cPG\u6703\u81ea\u52d5\u5c07\u6574\u6578\u8f49\u63db\u70ba\u6d6e\u9ede\u6578\u4ee5\u9032\u884c\u8a08\u7b97\u3002\u9019\u7a2e\u8f49\u63db\u901a\u5e38\u662f\u5b89\u5168\u7684\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u53ef\u80fd\u6703\u5c0e\u81f4\u7cbe\u5ea6\u640d\u5931\u3002<\/p>\n<h3 id=\"%e9%a1%af%e5%bc%8f%e8%bd%89%e6%8f%9b-BmutjyLKVh\">\u986f\u5f0f\u8f49\u63db<\/h3>\n<p>\u986f\u5f0f\u8f49\u63db\u5247\u9700\u8981\u4f7f\u7528CAST\u6216::\u904b\u7b97\u7b26\u4f86\u9032\u884c\u3002\u4f8b\u5982\uff0c\u5c07\u4e00\u500b\u6574\u6578\u8f49\u63db\u70ba\u5b57\u4e32\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>SELECT CAST(123 AS VARCHAR);<\/code><\/pre>\n<p>\u6216\u8005\u4f7f\u7528::\u904b\u7b97\u7b26\uff1a<\/p>\n<pre><code>SELECT 123::VARCHAR;<\/code><\/pre>\n<h2 id=\"%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%e7%9a%84%e6%96%b9%e6%b3%95-BmutjyLKVh\">\u6578\u64da\u985e\u578b\u8f49\u63db\u7684\u65b9\u6cd5<\/h2>\n<p>\u5728PG\u4e2d\uff0c\u6578\u64da\u985e\u578b\u8f49\u63db\u7684\u65b9\u6cd5\u4e3b\u8981\u6709\u4ee5\u4e0b\u5e7e\u7a2e\uff1a<\/p>\n<ul>\n<li><strong>CAST\u51fd\u6578\uff1a<\/strong>\u9019\u662f\u4e00\u500b\u6a19\u6e96SQL\u51fd\u6578\uff0c\u7528\u65bc\u5c07\u4e00\u7a2e\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\u6578\u64da\u985e\u578b\u3002<\/li>\n<li><strong>::\u904b\u7b97\u7b26\uff1a<\/strong>\u9019\u662fPG\u7279\u6709\u7684\u8a9e\u6cd5\uff0c\u63d0\u4f9b\u4e86\u4e00\u7a2e\u7c21\u4fbf\u7684\u65b9\u5f0f\u4f86\u9032\u884c\u6578\u64da\u985e\u578b\u8f49\u63db\u3002<\/li>\n<li><strong>\u4f7f\u7528\u5167\u5efa\u51fd\u6578\uff1a<\/strong>PG\u63d0\u4f9b\u4e86\u591a\u7a2e\u5167\u5efa\u51fd\u6578\u4f86\u8655\u7406\u7279\u5b9a\u7684\u6578\u64da\u985e\u578b\u8f49\u63db\uff0c\u4f8b\u5982TO_CHAR\u3001TO_DATE\u7b49\u3002<\/li>\n<\/ul>\n<h3 id=\"%e4%bd%bf%e7%94%a8cast%e5%87%bd%e6%95%b8%e7%9a%84%e7%a4%ba%e4%be%8b-BmutjyLKVh\">\u4f7f\u7528CAST\u51fd\u6578\u7684\u793a\u4f8b<\/h3>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528CAST\u51fd\u6578\u5c07\u65e5\u671f\u8f49\u63db\u70ba\u5b57\u4e32\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT CAST(NOW() AS VARCHAR);<\/code><\/pre>\n<h3 id=\"%e4%bd%bf%e7%94%a8%e9%81%8b%e7%ae%97%e7%ac%a6%e7%9a%84%e7%a4%ba%e4%be%8b-BmutjyLKVh\">\u4f7f\u7528::\u904b\u7b97\u7b26\u7684\u793a\u4f8b<\/h3>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528::\u904b\u7b97\u7b26\u5c07\u5b57\u4e32\u8f49\u63db\u70ba\u6574\u6578\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT '123'::INTEGER;<\/code><\/pre>\n<h2 id=\"%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-BmutjyLKVh\">\u6700\u4f73\u5be6\u8e10<\/h2>\n<p>\u5728\u9032\u884c\u6578\u64da\u985e\u578b\u8f49\u63db\u6642\uff0c\u9075\u5faa\u4e00\u4e9b\u6700\u4f73\u5be6\u8e10\u53ef\u4ee5\u5e6b\u52a9\u63d0\u9ad8\u6548\u7387\u548c\u5b89\u5168\u6027\uff1a<\/p>\n<ul>\n<li><strong>\u660e\u78ba\u6307\u5b9a\u8f49\u63db\uff1a<\/strong>\u5728\u9700\u8981\u8f49\u63db\u6578\u64da\u985e\u578b\u6642\uff0c\u61c9\u59cb\u7d42\u4f7f\u7528\u986f\u5f0f\u8f49\u63db\uff0c\u4ee5\u907f\u514d\u96b1\u5f0f\u8f49\u63db\u53ef\u80fd\u5e36\u4f86\u7684\u554f\u984c\u3002<\/li>\n<li><strong>\u6aa2\u67e5\u6578\u64da\u5b8c\u6574\u6027\uff1a<\/strong>\u5728\u9032\u884c\u8f49\u63db\u4e4b\u524d\uff0c\u61c9\u6aa2\u67e5\u6578\u64da\u7684\u5b8c\u6574\u6027\uff0c\u4ee5\u78ba\u4fdd\u8f49\u63db\u4e0d\u6703\u5c0e\u81f4\u6578\u64da\u4e1f\u5931\u6216\u932f\u8aa4\u3002<\/li>\n<li><strong>\u6e2c\u8a66\u8f49\u63db\u7d50\u679c\uff1a<\/strong>\u5728\u751f\u7522\u74b0\u5883\u4e2d\u9032\u884c\u6578\u64da\u985e\u578b\u8f49\u63db\u4e4b\u524d\uff0c\u61c9\u5728\u6e2c\u8a66\u74b0\u5883\u4e2d\u9032\u884c\u5145\u5206\u6e2c\u8a66\uff0c\u4ee5\u78ba\u4fdd\u8f49\u63db\u7684\u6b63\u78ba\u6027\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-BmutjyLKVh\">\u7d50\u8ad6<\/h2>\n<p>\u6578\u64da\u985e\u578b\u8f49\u63db\u5728PG\u6578\u64da\u5eab\u4e2d\u662f\u4e00\u500b\u91cd\u8981\u7684\u64cd\u4f5c\uff0c\u6b63\u78ba\u5730\u9032\u884c\u8f49\u63db\u53ef\u4ee5\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u6548\u7387\u548c\u6e96\u78ba\u6027\u3002\u901a\u904e\u4e86\u89e3\u96b1\u5f0f\u548c\u986f\u5f0f\u8f49\u63db\u7684\u5340\u5225\uff0c\u638c\u63e1CAST\u51fd\u6578\u548c::\u904b\u7b97\u7b26\u7684\u4f7f\u7528\uff0c\u4ee5\u53ca\u9075\u5faa\u6700\u4f73\u5be6\u8e10\uff0c\u60a8\u53ef\u4ee5\u5728PG\u4e2d\u9ad8\u6548\u5730\u7ba1\u7406\u6578\u64da\u985e\u578b\u8f49\u63db\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u6709\u66f4\u6df1\u5165\u7684\u9700\u6c42\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u642d\u5efa\u60a8\u7684\u6578\u64da\u5eab\u74b0\u5883\uff0c\u4eab\u53d7\u66f4\u9ad8\u7684\u6027\u80fd\u548c\u7a69\u5b9a\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 PG \u6578\u64da\u5eab\u4e2d\u9ad8\u6548\u8f49\u63db\u6578\u64da\u985e\u578b\u7684\u5168\u904e\u7a0b\uff0c\u5f9e\u982d\u5230\u5c3e\u638c\u63e1\u6280\u5de7\u8207\u6700\u4f73\u5be6\u8e10\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u80fd\u529b\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-153383","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/153383","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=153383"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/153383\/revisions"}],"predecessor-version":[{"id":153384,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/153383\/revisions\/153384"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=153383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=153383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=153383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}