{"id":20362,"date":"2024-01-02T04:55:21","date_gmt":"2024-01-02T04:55:21","guid":{"rendered":"https:\/\/server.hk\/blog\/20362\/"},"modified":"2024-11-14T10:39:46","modified_gmt":"2024-11-14T02:39:46","slug":"postgresql-command-create-domain","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/20362\/","title":{"rendered":"PostgreSQL \u6307\u4ee4\uff1aCREATE DOMAIN"},"content":{"rendered":"<h1 id=\"postgresql-command-create-domain-yGlQIXcUbV\">PostgreSQL \u6307\u4ee4\uff1aCREATE DOMAIN<\/h1>\n<p>PostgreSQL \u662f\u4e00\u500b\u529f\u80fd\u5f37\u5927\u7684\u958b\u6e90\u95dc\u4fc2\u578b\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u5ee3\u6cdb\u7684\u529f\u80fd\u548c\u7279\u6027\u3002<code>CREATE DOMAIN<\/code> \u6307\u4ee4\u662f PostgreSQL \u7684\u4e00\u500b\u95dc\u9375\u529f\u80fd\uff0c\u5141\u8a31\u7528\u6236\u5275\u5efa\u81ea\u5b9a\u7fa9\u8cc7\u6599\u985e\u578b\u3002\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u5c07\u63a2\u8a0e <code>CREATE DOMAIN<\/code> \u6307\u4ee4\u53ca\u5176\u5728 PostgreSQL \u4e2d\u7684\u61c9\u7528\u3002<\/p>\n<h2 id=\"what-is-a-domain-yGlQIXcUbV\">\u4ec0\u9ebc\u662f Domain\uff1f<\/h2>\n<p>\u5728 PostgreSQL \u4e2d\uff0cDomain \u662f\u4e00\u7a2e\u7528\u6236\u81ea\u5b9a\u7fa9\u7684\u8cc7\u6599\u985e\u578b\uff0c\u5141\u8a31\u60a8\u5c0d\u7279\u5b9a\u7684\u8cc7\u6599\u985e\u578b\u5b9a\u7fa9\u7d04\u675f\u548c\u898f\u5247\u3002\u5b83\u901a\u904e\u9650\u5236\u6b04\u4f4d\u4e2d\u53ef\u4ee5\u5b58\u5132\u7684\u503c\u4f86\u5f37\u5236\u5be6\u73fe\u6578\u64da\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u60a8\u6709\u4e00\u500b\u540d\u70ba &#8220;employees&#8221; \u7684\u8868\uff0c\u5176\u4e2d\u6709\u4e00\u500b\u540d\u70ba &#8220;age&#8221; \u7684\u6b04\u4f4d\u3002\u8207\u5176\u70ba &#8220;age&#8221; \u6b04\u4f4d\u4f7f\u7528\u5167\u5efa\u7684\u6574\u6578\u8cc7\u6599\u985e\u578b\uff0c\u60a8\u53ef\u4ee5\u5275\u5efa\u4e00\u500b\u540d\u70ba &#8220;employee_age&#8221; \u7684 Domain\uff0c\u5c07\u5e74\u9f61\u9650\u5236\u5728 18 \u5230 65 \u6b72\u4e4b\u9593\u3002\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u53ea\u6709\u6709\u6548\u7684\u5e74\u9f61\u503c\u624d\u80fd\u5b58\u5132\u5728 &#8220;age&#8221; \u6b04\u4f4d\u4e2d\u3002<\/p>\n<h2 id=\"creating-a-domain-yGlQIXcUbV\">\u5275\u5efa Domain<\/h2>\n<p>\u5728 PostgreSQL \u4e2d\u5275\u5efa Domain \u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE DOMAIN domain_name AS data_type\r\n   [DEFAULT default_value]\r\n   [constraint1]\r\n   [constraint2]\r\n   ...\r\n   [constraint_n];\r\n<\/code><\/pre>\n<p>\u8b93\u6211\u5011\u4f86\u5206\u89e3\u4e00\u4e0b\u9019\u500b\u8a9e\u6cd5\uff1a<\/p>\n<ul>\n<li><code>domain_name<\/code>\uff1a\u60a8\u60f3\u8981\u5275\u5efa\u7684 Domain \u7684\u540d\u7a31\u3002<\/li>\n<li><code>data_type<\/code>\uff1aDomain \u7684\u57fa\u790e\u8cc7\u6599\u985e\u578b\u3002<\/li>\n<li><code>DEFAULT default_value<\/code>\uff08\u53ef\u9078\uff09\uff1a\u6307\u5b9a Domain \u7684\u9810\u8a2d\u503c\u3002<\/li>\n<li><code>constraint1, constraint2, ..., constraint_n<\/code>\uff08\u53ef\u9078\uff09\uff1a\u70ba Domain \u6307\u5b9a\u7684\u7d04\u675f\u689d\u4ef6\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u5275\u5efa\u540d\u70ba &#8220;employee_age&#8221; \u7684 Domain \u7684\u7bc4\u4f8b\uff0c\u5b83\u4f7f\u7528\u6574\u6578\u8cc7\u6599\u985e\u578b\u4e26\u5e36\u6709\u4e00\u500b\u6aa2\u67e5\u7d04\u675f\uff1a<\/p>\n<pre><code>CREATE DOMAIN employee_age AS integer\r\n   CHECK (VALUE BETWEEN 18 AND 65);\r\n<\/code><\/pre>\n<p>\u5728\u6b64\u7bc4\u4f8b\u4e2d\uff0c&#8221;employee_age&#8221; Domain \u5c07\u503c\u9650\u5236\u70ba 18 \u5230 65 \u4e4b\u9593\u7684\u6574\u6578\u3002<\/p>\n<h2 id=\"using-a-domain-yGlQIXcUbV\">\u4f7f\u7528 Domain<\/h2>\n<p>\u5275\u5efa Domain \u4e4b\u5f8c\uff0c\u60a8\u53ef\u4ee5\u5728\u5b9a\u7fa9\u8868\u683c\u7684\u6b04\u4f4d\u6642\u4f7f\u7528\u5b83\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u7bc4\u4f8b\uff1a<\/p>\n<pre><code>CREATE TABLE employees (\r\n   id serial PRIMARY KEY,\r\n   name varchar(100),\r\n   age employee_age\r\n);\r\n<\/code><\/pre>\n<p>\u5728\u6b64\u7bc4\u4f8b\u4e2d\uff0c&#8221;employees&#8221; \u8868\u4e2d\u7684 &#8220;age&#8221; \u6b04\u4f4d\u4f7f\u7528\u4e86 &#8220;employee_age&#8221; Domain\u3002\u9019\u78ba\u4fdd\u4e86 &#8220;age&#8221; \u6b04\u4f4d\u4e2d\u53ea\u6703\u5b58\u5132\u6709\u6548\u7684\u5e74\u9f61\u503c\u3002<\/p>\n<h2 id=\"summary-yGlQIXcUbV\">\u6458\u8981<\/h2>\n<p>PostgreSQL \u4e2d\u7684 <code>CREATE DOMAIN<\/code> \u6307\u4ee4\u5141\u8a31\u60a8\u5275\u5efa\u5e36\u6709\u7d04\u675f\u548c\u898f\u5247\u7684\u81ea\u5b9a\u7fa9\u8cc7\u6599\u985e\u578b\u3002Domain \u70ba\u60a8\u7684\u8cc7\u6599\u5eab\u63d0\u4f9b\u4e86\u4e00\u7a2e\u5be6\u65bd\u6578\u64da\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u7684\u65b9\u5f0f\u3002\u901a\u904e\u4f7f\u7528 Domain\uff0c\u60a8\u53ef\u4ee5\u70ba\u8cc7\u6599\u985e\u578b\u5b9a\u7fa9\u7279\u5b9a\u7684\u898f\u5247\uff0c\u78ba\u4fdd\u5728\u8868\u683c\u4e2d\u53ea\u5b58\u5132\u6709\u6548\u7684\u503c\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u53ef\u9760\u7684\u9999\u6e2f VPS \u8a17\u7ba1\u670d\u52d9\u4f9b\u61c9\u5546\uff0c\u8acb\u8003\u616e <a href=\"https:\/\/server.hk\">Server.HK<\/a>\u3002Server.HK \u63d0\u4f9b\u9802\u7d1a\u7684 VPS \u89e3\u6c7a\u65b9\u6848\u548c\u5353\u8d8a\u7684\u5ba2\u6236\u652f\u6301\uff0c\u662f\u60a8\u8a17\u7ba1\u9700\u6c42\u7684\u5b8c\u7f8e\u9078\u64c7\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-20362","post","type-post","status-publish","format-standard","hentry","category-setup-tutorials"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20362","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=20362"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20362\/revisions"}],"predecessor-version":[{"id":24393,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/20362\/revisions\/24393"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=20362"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=20362"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=20362"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}