{"id":96232,"date":"2024-10-20T07:42:16","date_gmt":"2024-10-19T23:42:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96232\/"},"modified":"2024-10-20T07:42:17","modified_gmt":"2024-10-19T23:42:17","slug":"oracle%e7%b4%84%e6%9d%9f%e7%9a%84%e6%b7%bb%e5%8a%a0%e6%96%b9%e6%b3%95%e7%9a%84%e6%8f%8f%e8%bf%b0","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96232\/","title":{"rendered":"Oracle\u7d04\u675f\u7684\u6dfb\u52a0\u65b9\u6cd5\u7684\u63cf\u8ff0"},"content":{"rendered":"<h1 id=\"oracle%e7%b4%84%e6%9d%9f%e7%9a%84%e6%b7%bb%e5%8a%a0%e6%96%b9%e6%b3%95%e7%9a%84%e6%8f%8f%e8%bf%b0-MNKObcSAhW\">Oracle\u7d04\u675f\u7684\u6dfb\u52a0\u65b9\u6cd5\u7684\u63cf\u8ff0<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u7d04\u675f\uff08Constraint\uff09\u662f\u7528\u4f86\u9650\u5236\u8cc7\u6599\u8868\u4e2d\u8cc7\u6599\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u7684\u91cd\u8981\u5de5\u5177\u3002Oracle\u8cc7\u6599\u5eab\u63d0\u4f9b\u4e86\u591a\u7a2e\u7d04\u675f\u985e\u578b\uff0c\u5305\u62ec\u4e3b\u9375\u7d04\u675f\u3001\u5916\u9375\u7d04\u675f\u3001\u552f\u4e00\u7d04\u675f\u3001\u6aa2\u67e5\u7d04\u675f\u548c\u9810\u8a2d\u7d04\u675f\u3002\u672c\u6587\u5c07\u8a73\u7d30\u4ecb\u7d39\u5982\u4f55\u5728Oracle\u4e2d\u6dfb\u52a0\u9019\u4e9b\u7d04\u675f\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u7bc4\u4f8b\u3002<\/p>\n<h2 id=\"1-%e4%b8%bb%e9%8d%b5%e7%b4%84%e6%9d%9f%ef%bc%88primary-key-constraint%ef%bc%89-MNKObcSAhW\">1. \u4e3b\u9375\u7d04\u675f\uff08Primary Key Constraint\uff09<\/h2>\n<p>\u4e3b\u9375\u7d04\u675f\u7528\u65bc\u552f\u4e00\u6a19\u8b58\u8cc7\u6599\u8868\u4e2d\u7684\u6bcf\u4e00\u884c\u3002\u6bcf\u500b\u8cc7\u6599\u8868\u53ea\u80fd\u6709\u4e00\u500b\u4e3b\u9375\uff0c\u4e14\u4e3b\u9375\u7684\u503c\u4e0d\u80fd\u70ba\u7a7a\u3002<\/p>\n<h3 id=\"%e6%b7%bb%e5%8a%a0%e4%b8%bb%e9%8d%b5%e7%b4%84%e6%9d%9f%e7%9a%84%e8%aa%9e%e6%b3%95-MNKObcSAhW\">\u6dfb\u52a0\u4e3b\u9375\u7d04\u675f\u7684\u8a9e\u6cd5<\/h3>\n<pre><code>ALTER TABLE table_name\nADD CONSTRAINT constraint_name PRIMARY KEY (column1, column2, ...);<\/code><\/pre>\n<h3 id=\"%e7%af%84%e4%be%8b-MNKObcSAhW\">\u7bc4\u4f8b<\/h3>\n<pre><code>ALTER TABLE employees\nADD CONSTRAINT pk_employee_id PRIMARY KEY (employee_id);<\/code><\/pre>\n<h2 id=\"2-%e5%a4%96%e9%8d%b5%e7%b4%84%e6%9d%9f%ef%bc%88foreign-key-constraint%ef%bc%89-MNKObcSAhW\">2. \u5916\u9375\u7d04\u675f\uff08Foreign Key Constraint\uff09<\/h2>\n<p>\u5916\u9375\u7d04\u675f\u7528\u65bc\u5efa\u7acb\u5169\u500b\u8cc7\u6599\u8868\u4e4b\u9593\u7684\u95dc\u806f\uff0c\u78ba\u4fdd\u8cc7\u6599\u7684\u53c3\u8003\u5b8c\u6574\u6027\u3002\u5916\u9375\u7684\u503c\u5fc5\u9808\u5b58\u5728\u65bc\u53c3\u8003\u7684\u4e3b\u9375\u4e2d\u3002<\/p>\n<h3 id=\"%e6%b7%bb%e5%8a%a0%e5%a4%96%e9%8d%b5%e7%b4%84%e6%9d%9f%e7%9a%84%e8%aa%9e%e6%b3%95-MNKObcSAhW\">\u6dfb\u52a0\u5916\u9375\u7d04\u675f\u7684\u8a9e\u6cd5<\/h3>\n<pre><code>ALTER TABLE table_name\nADD CONSTRAINT constraint_name FOREIGN KEY (column_name)\nREFERENCES parent_table (parent_column);<\/code><\/pre>\n<h3 id=\"%e7%af%84%e4%be%8b-MNKObcSAhW\">\u7bc4\u4f8b<\/h3>\n<pre><code>ALTER TABLE orders\nADD CONSTRAINT fk_employee_id FOREIGN KEY (employee_id)\nREFERENCES employees (employee_id);<\/code><\/pre>\n<h2 id=\"3-%e5%94%af%e4%b8%80%e7%b4%84%e6%9d%9f%ef%bc%88unique-constraint%ef%bc%89-MNKObcSAhW\">3. \u552f\u4e00\u7d04\u675f\uff08Unique Constraint\uff09<\/h2>\n<p>\u552f\u4e00\u7d04\u675f\u78ba\u4fdd\u8cc7\u6599\u8868\u4e2d\u7684\u67d0\u4e00\u5217\u6216\u591a\u5217\u7684\u503c\u662f\u552f\u4e00\u7684\uff0c\u4e26\u4e14\u4e0d\u5141\u8a31\u91cd\u8907\u3002\u8207\u4e3b\u9375\u4e0d\u540c\u7684\u662f\uff0c\u552f\u4e00\u7d04\u675f\u53ef\u4ee5\u6709\u7a7a\u503c\u3002<\/p>\n<h3 id=\"%e6%b7%bb%e5%8a%a0%e5%94%af%e4%b8%80%e7%b4%84%e6%9d%9f%e7%9a%84%e8%aa%9e%e6%b3%95-MNKObcSAhW\">\u6dfb\u52a0\u552f\u4e00\u7d04\u675f\u7684\u8a9e\u6cd5<\/h3>\n<pre><code>ALTER TABLE table_name\nADD CONSTRAINT constraint_name UNIQUE (column1, column2, ...);<\/code><\/pre>\n<h3 id=\"%e7%af%84%e4%be%8b-MNKObcSAhW\">\u7bc4\u4f8b<\/h3>\n<pre><code>ALTER TABLE users\nADD CONSTRAINT uq_email UNIQUE (email);<\/code><\/pre>\n<h2 id=\"4-%e6%aa%a2%e6%9f%a5%e7%b4%84%e6%9d%9f%ef%bc%88check-constraint%ef%bc%89-MNKObcSAhW\">4. \u6aa2\u67e5\u7d04\u675f\uff08Check Constraint\uff09<\/h2>\n<p>\u6aa2\u67e5\u7d04\u675f\u7528\u65bc\u9650\u5236\u67d0\u4e00\u5217\u7684\u503c\u5fc5\u9808\u6eff\u8db3\u7279\u5b9a\u689d\u4ef6\u3002\u9019\u6709\u52a9\u65bc\u78ba\u4fdd\u8cc7\u6599\u7684\u6709\u6548\u6027\u3002<\/p>\n<h3 id=\"%e6%b7%bb%e5%8a%a0%e6%aa%a2%e6%9f%a5%e7%b4%84%e6%9d%9f%e7%9a%84%e8%aa%9e%e6%b3%95-MNKObcSAhW\">\u6dfb\u52a0\u6aa2\u67e5\u7d04\u675f\u7684\u8a9e\u6cd5<\/h3>\n<pre><code>ALTER TABLE table_name\nADD CONSTRAINT constraint_name CHECK (condition);<\/code><\/pre>\n<h3 id=\"%e7%af%84%e4%be%8b-MNKObcSAhW\">\u7bc4\u4f8b<\/h3>\n<pre><code>ALTER TABLE products\nADD CONSTRAINT chk_price CHECK (price &gt; 0);<\/code><\/pre>\n<h2 id=\"5-%e9%a0%90%e8%a8%ad%e7%b4%84%e6%9d%9f%ef%bc%88default-constraint%ef%bc%89-MNKObcSAhW\">5. \u9810\u8a2d\u7d04\u675f\uff08Default Constraint\uff09<\/h2>\n<p>\u9810\u8a2d\u7d04\u675f\u7528\u65bc\u70ba\u67d0\u4e00\u5217\u6307\u5b9a\u9810\u8a2d\u503c\uff0c\u7576\u63d2\u5165\u8cc7\u6599\u6642\u5982\u679c\u672a\u63d0\u4f9b\u8a72\u5217\u7684\u503c\uff0c\u5247\u4f7f\u7528\u9810\u8a2d\u503c\u3002<\/p>\n<h3 id=\"%e6%b7%bb%e5%8a%a0%e9%a0%90%e8%a8%ad%e7%b4%84%e6%9d%9f%e7%9a%84%e8%aa%9e%e6%b3%95-MNKObcSAhW\">\u6dfb\u52a0\u9810\u8a2d\u7d04\u675f\u7684\u8a9e\u6cd5<\/h3>\n<pre><code>ALTER TABLE table_name\nADD CONSTRAINT constraint_name DEFAULT default_value FOR column_name;<\/code><\/pre>\n<h3 id=\"%e7%af%84%e4%be%8b-MNKObcSAhW\">\u7bc4\u4f8b<\/h3>\n<pre><code>ALTER TABLE employees\nADD CONSTRAINT df_hire_date DEFAULT SYSDATE FOR hire_date;<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-MNKObcSAhW\">\u7e3d\u7d50<\/h2>\n<p>\u5728Oracle\u8cc7\u6599\u5eab\u4e2d\uff0c\u7d04\u675f\u7684\u6dfb\u52a0\u662f\u78ba\u4fdd\u8cc7\u6599\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u7684\u95dc\u9375\u6b65\u9a5f\u3002\u900f\u904e\u4e3b\u9375\u3001\u5916\u9375\u3001\u552f\u4e00\u3001\u6aa2\u67e5\u548c\u9810\u8a2d\u7d04\u675f\u7684\u4f7f\u7528\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u8cc7\u6599\u8868\u4e2d\u7684\u8cc7\u6599\u3002\u4e86\u89e3\u9019\u4e9b\u7d04\u675f\u7684\u6dfb\u52a0\u65b9\u6cd5\uff0c\u5c0d\u65bc\u8cc7\u6599\u5eab\u8a2d\u8a08\u548c\u7ba1\u7406\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<p>\u5982\u9700\u9032\u4e00\u6b65\u4e86\u89e3\u6709\u95dc <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u548c\u5176\u4ed6\u4f3a\u670d\u5668\u89e3\u6c7a\u65b9\u6848\u7684\u4fe1\u606f\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3Oracle\u7d04\u675f\u7684\u6dfb\u52a0\u65b9\u6cd5\uff0c\u638c\u63e1\u5982\u4f55\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u5b8c\u6574\u6027\u548c\u7d04\u675f\u689d\u4ef6\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\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-96232","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96232","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=96232"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96232\/revisions"}],"predecessor-version":[{"id":96233,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96232\/revisions\/96233"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}