{"id":20772,"date":"2024-01-02T05:41:27","date_gmt":"2024-01-02T05:41:27","guid":{"rendered":"https:\/\/server.hk\/blog\/20772\/"},"modified":"2024-11-14T10:38:58","modified_gmt":"2024-11-14T02:38:58","slug":"postgresql-command-create-transform","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/20772\/","title":{"rendered":"PostgreSQL \u547d\u4ee4\uff1aCREATE TRANSFORM"},"content":{"rendered":"<h1 id=\"postgresql-command-create-transform-hWfDhzQjcY\">PostgreSQL \u547d\u4ee4\uff1aCREATE TRANSFORM<\/h1>\n<p>PostgreSQL \u662f\u4e00\u6b3e\u529f\u80fd\u5f37\u5927\u7684\u958b\u6e90\u95dc\u806f\u5f0f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u5ee3\u6cdb\u7684\u529f\u80fd\u548c\u7279\u6027\u3002\u5176\u4e2d PostgreSQL \u7684\u91cd\u8981\u529f\u80fd\u4e4b\u4e00\u662f\u900f\u904e\u5404\u7a2e\u547d\u4ee4\u548c\u51fd\u6578\u64f4\u5c55\u5176\u529f\u80fd\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u5c07\u63a2\u7d22 PostgreSQL \u7684 <code>CREATE TRANSFORM<\/code> \u547d\u4ee4\uff0c\u4e26\u7406\u89e3\u5982\u4f55\u904b\u7528\u5b83\u4f86\u589e\u5f37\u6578\u64da\u5eab\u7684\u80fd\u529b\u3002<\/p>\n<h2 id=\"introduction-to-create-transform-hWfDhzQjcY\">\u4ecb\u7d39 CREATE TRANSFORM<\/h2>\n<p>\u5728 PostgreSQL \u4e2d\uff0c<code>CREATE TRANSFORM<\/code> \u547d\u4ee4\u5141\u8a31\u7528\u6236\u5b9a\u7fa9\u81ea\u8a02\u7684\u6578\u64da\u8f49\u63db\uff0c\u53ef\u5728 SQL \u67e5\u8a62\u4e2d\u4f7f\u7528\u3002\u9019\u4e9b\u8f49\u63db\u53ef\u61c9\u7528\u65bc\u7279\u5b9a\u7684\u6578\u64da\u985e\u578b\uff0c\u4f7f\u7528\u6236\u80fd\u5920\u4ee5\u81ea\u8a02\u65b9\u5f0f\u64cd\u4f5c\u548c\u8655\u7406\u6578\u64da\u3002<\/p>\n<p>\u7576\u8655\u7406\u5fa9\u96dc\u7684\u6578\u64da\u985e\u578b\u6216\u9700\u8981\u7279\u5b9a\u7684\u6578\u64da\u64cd\u4f5c\u6642\uff0c\u9032\u884c\u8f49\u63db\u5c24\u5176\u6709\u7528\u3002\u901a\u904e\u5b9a\u7fa9\u81ea\u8a02\u8f49\u63db\uff0c\u7528\u6236\u53ef\u4ee5\u7c21\u5316\u5176 SQL \u67e5\u8a62\u4e26\u63d0\u9ad8\u6578\u64da\u5eab\u64cd\u4f5c\u7684\u6574\u9ad4\u6548\u7387\u3002<\/p>\n<h2 id=\"creating-a-transform-hWfDhzQjcY\">\u5275\u5efa\u8f49\u63db<\/h2>\n<p>\u8981\u5728 PostgreSQL \u4e2d\u5275\u5efa\u8f49\u63db\uff0c\u9700\u8981\u4f7f\u7528 <code>CREATE TRANSFORM<\/code> \u547d\u4ee4\uff0c\u5f8c\u8ddf\u8f49\u63db\u540d\u7a31\u3001\u6e90\u6578\u64da\u985e\u578b\u548c\u76ee\u6a19\u6578\u64da\u985e\u578b\u3002\u4ee5\u4e0b\u662f\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>CREATE TRANSFORM transform_name (source_data_type, destination_data_type)\r\n  TYPE transform_type\r\n  LANGUAGE transform_language\r\n  IMMUTABLE | STABLE | VOLATILE\r\n  <em>transform_function<\/em>;\r\n<\/code><\/pre>\n<p>\u8b93\u6211\u5011\u4f86\u4e86\u89e3\u8a9e\u6cd5\u7684\u5404\u500b\u7d44\u6210\u90e8\u5206\uff1a<\/p>\n<ul>\n<li><code>transform_name<\/code>\uff1a\u60a8\u60f3\u8981\u5275\u5efa\u7684\u8f49\u63db\u7684\u540d\u7a31\u3002<\/li>\n<li><code>source_data_type<\/code>\uff1a\u8f49\u63db\u5c07\u61c9\u7528\u7684\u6578\u64da\u985e\u578b\u3002<\/li>\n<li><code>destination_data_type<\/code>\uff1a\u61c9\u7528\u8f49\u63db\u5f8c\u7684\u7d50\u679c\u6578\u64da\u985e\u578b\u3002<\/li>\n<li><code>transform_type<\/code>\uff1a\u8f49\u63db\u7684\u985e\u578b\uff0c\u53ef\u4ee5\u662f <code>FUNCTION<\/code> \u6216 <code>ROUTINE<\/code>\u3002<\/li>\n<li><code>transform_language<\/code>\uff1a\u5be6\u73fe\u8f49\u63db\u7684\u7de8\u7a0b\u8a9e\u8a00\u3002<\/li>\n<li><code>IMMUTABLE | STABLE | VOLATILE<\/code>\uff1a\u6307\u5b9a\u8f49\u63db\u51fd\u6578\u7684\u4e0d\u8b8a\u6027\u3002<\/li>\n<li><code>transform_function<\/code>\uff1a\u5be6\u969b\u57f7\u884c\u8f49\u63db\u7684\u51fd\u6578\u3002<\/li>\n<\/ul>\n<h2 id=\"example-hWfDhzQjcY\">\u7bc4\u4f8b<\/h2>\n<p>\u8b93\u6211\u5011\u5047\u8a2d\u6211\u5011\u8981\u5275\u5efa\u4e00\u500b\u8f49\u63db\uff0c\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u5927\u5beb\u3002\u6211\u5011\u53ef\u4ee5\u5b9a\u7fa9\u8a72\u8f49\u63db\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE TRANSFORM uppercase_transform (text, text)\r\n  TYPE FUNCTION\r\n  LANGUAGE SQL\r\n  IMMUTABLE\r\n  <em>UPPER<\/em>;\r\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u5c07\u8f49\u63db\u547d\u540d\u70ba <code>uppercase_transform<\/code>\uff0c\u4e26\u6307\u5b9a\u5b83\u4ee5 <code>text<\/code> \u6578\u64da\u985e\u578b\u4f5c\u70ba\u8f38\u5165\uff0c\u8fd4\u56de <code>text<\/code> \u6578\u64da\u985e\u578b\u3002\u6211\u5011\u4f7f\u7528\u4e86 <code>UPPER<\/code> \u51fd\u6578\uff0c\u9019\u662f PostgreSQL \u5167\u5efa\u7684\u4e00\u500b\u51fd\u6578\uff0c\u53ef\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u5927\u5beb\uff0c\u4f5c\u70ba\u8f49\u63db\u51fd\u6578\u3002<\/p>\n<h2 id=\"using-the-transform-hWfDhzQjcY\">\u4f7f\u7528\u8f49\u63db<\/h2>\n<p>\u4e00\u65e6\u5275\u5efa\u4e86\u8f49\u63db\uff0c\u60a8\u53ef\u4ee5\u5728 SQL \u67e5\u8a62\u4e2d\u4f7f\u7528\u5b83\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f8b\u5b50\uff1a<\/p>\n<pre><code>SELECT column_name\r\nFROM table_name\r\nWHERE column_name = 'example'::uppercase_transform;\r\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u4f7f\u7528\u4e86 <code>uppercase_transform<\/code> \u8f49\u63db\uff0c\u5c07\u5b57\u7b26\u4e32 &#8216;example&#8217; \u8f49\u63db\u70ba\u5927\u5beb\u5f8c\uff0c\u518d\u8207 <code>table_name<\/code> \u8868\u7684 <code>column_name<\/code> \u5217\u4e2d\u7684\u503c\u9032\u884c\u6bd4\u8f03\u3002<\/p>\n<h2 id=\"summary-hWfDhzQjcY\">\u7e3d\u7d50<\/h2>\n<p>PostgreSQL \u4e2d\u7684 <code>CREATE TRANSFORM<\/code> \u547d\u4ee4\u5141\u8a31\u7528\u6236\u5b9a\u7fa9\u53ef\u61c9\u7528\u65bc\u7279\u5b9a\u6578\u64da\u985e\u578b\u7684\u81ea\u5b9a\u7fa9\u6578\u64da\u8f49\u63db\u3002\u901a\u904e\u5275\u5efa\u8f49\u63db\uff0c\u7528\u6236\u53ef\u4ee5\u7c21\u5316\u5176 SQL \u67e5\u8a62\u4e26\u9ad8\u6548\u5730\u57f7\u884c\u8907\u96dc\u7684\u6578\u64da\u64cd\u4f5c\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u63a2\u8a0e\u4e86\u5275\u5efa\u8f49\u63db\u7684\u57fa\u672c\u77e5\u8b58\u4ee5\u53ca\u5728 SQL \u67e5\u8a62\u4e2d\u4f7f\u7528\u5b83\u7684\u65b9\u6cd5\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u4e00\u500b\u53ef\u9760\u7684 VPS \u8a17\u7ba1\u670d\u52d9\u63d0\u4f9b\u5546\uff0c\u652f\u6301 PostgreSQL \u4e26\u63d0\u4f9b\u5353\u8d8a\u7684\u6027\u80fd\uff0c\u8acb\u8003\u616e<a href=\"https:\/\/server.hk\">Server.HK<\/a>\u3002\u6191\u85c9\u5176\u5148\u9032\u7684\u57fa\u790e\u8a2d\u65bd\u548c\u51fa\u8272\u7684\u5ba2\u6236\u652f\u6301\uff0c\u5b83\u662f\u8a17\u7ba1\u60a8\u7684 PostgreSQL \u6578\u64da\u5eab\u7684\u4fe1\u8cf4\u9078\u64c7\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>PostgreSQL \u547d\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-20772","post","type-post","status-publish","format-standard","hentry","category-setup-tutorials"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20772","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=20772"}],"version-history":[{"count":2,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20772\/revisions"}],"predecessor-version":[{"id":24334,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20772\/revisions\/24334"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=20772"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=20772"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=20772"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}