{"id":199672,"date":"2025-05-06T08:49:11","date_gmt":"2025-05-06T00:49:11","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199672\/"},"modified":"2025-05-06T08:49:11","modified_gmt":"2025-05-06T00:49:11","slug":"%e6%b7%b1%e5%85%a5%e4%ba%86%e8%a7%a3mysql%e7%9a%84%e7%ba%a6%e6%9d%9f%e7%ba%a6%e6%9d%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199672\/","title":{"rendered":"\u6df1\u5165\u4e86\u89e3MySQL\u7684\u7ea6\u675f\u7ea6\u675f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u6df1\u5165\u4e86\u89e3MySQL\u7684\u7ea6\u675f\u7ea6\u675f<\/h1>\n<p>\u73cd\u60dc\u65f6\u95f4\uff0c\u52e4\u594b\u5b66\u4e60\uff01\u4eca\u5929\u7ed9\u5927\u5bb6\u5e26\u6765\uff0c\u6b63\u6587\u5185\u5bb9\u4e3b\u8981\u6d89\u53ca\u5230\u7b49\u7b49\uff0c\u5982\u679c\u4f60\u6b63\u5728\u5b66\u4e60\uff0c\u6216\u8005\u662f\u5bf9\u6709\u7591\u95ee\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u6211\uff01\u540e\u9762\u6211\u4f1a\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u5185\u5bb9\u7684\uff0c\u5e0c\u671b\u90fd\u80fd\u5e2e\u5230\u6b63\u5728\u5b66\u4e60\u7684\u5927\u5bb6\uff01<\/p>\n<p>MySQL\u4e2dconstraint\u7684\u8be6\u89e3<\/p>\n<p>\u5728MySQL\u6570\u636e\u5e93\u4e2d\uff0cconstraint\uff08\u7ea6\u675f\uff09\u662f\u7528\u6765\u5b9a\u4e49\u548c\u9650\u5236\u8868\u4e2d\u5217\u7684\u53d6\u503c\u8303\u56f4\u548c\u6570\u636e\u5b8c\u6574\u6027\u7684\u89c4\u5219\u3002\u901a\u8fc7\u5728\u8868\u7684\u521b\u5efa\u8fc7\u7a0b\u4e2d\u4e3a\u5217\u6dfb\u52a0\u7ea6\u675f\uff0c\u53ef\u4ee5\u786e\u4fdd\u6570\u636e\u7684\u6b63\u786e\u6027\u548c\u4e00\u81f4\u6027\u3002\u672c\u6587\u5c06\u4ecb\u7ecdMySQL\u4e2d\u5e38\u7528\u7684\u7ea6\u675f\u7c7b\u578b\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n<ol>\n<li>PRIMARY KEY\uff08\u4e3b\u952e\u7ea6\u675f\uff09<br \/>\u4e3b\u952e\u662f\u9488\u5bf9\u4e00\u5f20\u8868\u4e2d\u7684\u4e00\u5217\u6216\u4e00\u7ec4\u5217\u7684\u552f\u4e00\u6807\u8bc6\u3002\u5b83\u4eec\u4fdd\u8bc1\u8868\u4e2d\u6bcf\u4e00\u884c\u7684\u552f\u4e00\u6027\u3002\u4f7f\u7528PRIMARY KEY\u7ea6\u675f\u53ef\u4ee5\u786e\u4fdd\u4e00\u4e2a\u8868\u4e2d\u53ea\u6709\u4e00\u4e2a\u4e3b\u952e\uff0c\u4e14\u4e0d\u80fd\u6709\u91cd\u590d\u503c\u3002<br \/>\u4e0b\u9762\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u6f14\u793a\u5982\u4f55\u4e3a\u8868\u6dfb\u52a0\u4e3b\u952e\u7ea6\u675f\uff1a<\/li>\n<\/ol>\n<pre>CREATE TABLE students (\n    id INT PRIMARY KEY,\n    name VARCHAR(50),\n    age INT\n);<\/pre>\n<ol>\n<li>FOREIGN KEY\uff08\u5916\u952e\u7ea6\u675f\uff09<br \/>\u5916\u952e\u7528\u4e8e\u5728\u591a\u4e2a\u8868\u4e4b\u95f4\u5efa\u7acb\u5173\u7cfb\u3002\u5b83\u662f\u4e00\u4e2a\u5217\u6216\u4e00\u7ec4\u5217\uff0c\u5b83\u4eec\u5f15\u7528\u53e6\u4e00\u5f20\u8868\u7684\u4e3b\u952e\uff0c\u4ee5\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002\u5f53\u5728\u5916\u952e\u5217\u4e0a\u5b9a\u4e49\u4e86FOREIGN KEY\u7ea6\u675f\u540e\uff0cMySQL\u5c06\u4f1a\u81ea\u52a8\u68c0\u67e5\u63d2\u5165\u6216\u66f4\u65b0\u7684\u503c\u662f\u5426\u5b58\u5728\u4e8e\u5173\u8054\u8868\u4e2d\u3002<br \/>\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u4e3a\u8868\u6dfb\u52a0\u5916\u952e\u7ea6\u675f\uff1a<\/li>\n<\/ol>\n<pre>CREATE TABLE orders (\n    order_id INT PRIMARY KEY,\n    product_id INT,\n    customer_id INT,\n    FOREIGN KEY (product_id) REFERENCES products(product_id),\n    FOREIGN KEY (customer_id) REFERENCES customers(customer_id)\n);<\/pre>\n<ol>\n<li>UNIQUE\uff08\u552f\u4e00\u7ea6\u675f\uff09<br \/>\u552f\u4e00\u7ea6\u675f\u786e\u4fdd\u4e00\u4e2a\u8868\u4e2d\u7684\u67d0\u4e00\u5217\u53ea\u63a5\u53d7\u552f\u4e00\u7684\u503c\u3002\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u4f60\u53ef\u80fd\u60f3\u8981\u4e3a\u4e00\u4e2a\u5217\u6dfb\u52a0UNIQUE\u7ea6\u675f\uff0c\u4ee5\u907f\u514d\u91cd\u590d\u7684\u503c\u3002<br \/>\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u4e3a\u8868\u6dfb\u52a0\u552f\u4e00\u7ea6\u675f\uff1a<\/li>\n<\/ol>\n<pre>CREATE TABLE employees (\n    employee_id INT PRIMARY KEY,\n    email VARCHAR(50) UNIQUE,\n    department_id INT\n);<\/pre>\n<ol>\n<li>CHECK\uff08\u68c0\u67e5\u7ea6\u675f\uff09<br \/>CHECK\u7ea6\u675f\u7528\u4e8e\u81ea\u5b9a\u4e49\u8868\u4e2d\u5217\u7684\u53d6\u503c\u8303\u56f4\u3002\u901a\u8fc7\u4f7f\u7528CHECK\u7ea6\u675f\uff0c\u53ef\u4ee5\u786e\u4fdd\u53ea\u6709\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u6570\u636e\u624d\u80fd\u88ab\u63d2\u5165\u8868\u4e2d\u3002<br \/>\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u6f14\u793a\u5982\u4f55\u4f7f\u7528CHECK\u7ea6\u675f\uff1a<\/li>\n<\/ol>\n<pre>CREATE TABLE products (\n    product_id INT PRIMARY KEY,\n    product_name VARCHAR(50),\n    quantity INT,\n    price DECIMAL(10, 2),\n    CONSTRAINT CHK_quantity CHECK (quantity &gt;= 0),\n    CONSTRAINT CHK_price CHECK (price &gt; 0)\n);<\/pre>\n<ol>\n<li>DEFAULT\uff08\u9ed8\u8ba4\u7ea6\u675f\uff09<br \/>DEFAULT\u7ea6\u675f\u7528\u4e8e\u4e3a\u5217\u8bbe\u7f6e\u9ed8\u8ba4\u503c\uff0c\u4ee5\u4fbf\u5728\u63d2\u5165\u65b0\u884c\u65f6\uff0c\u5982\u679c\u672a\u663e\u5f0f\u63d0\u4f9b\u503c\uff0c\u5219\u81ea\u52a8\u4f7f\u7528\u9ed8\u8ba4\u503c\u3002<br \/>\u4ee5\u4e0b\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u4e3a\u8868\u6dfb\u52a0\u9ed8\u8ba4\u7ea6\u675f\uff1a<\/li>\n<\/ol>\n<pre>CREATE TABLE users (\n    user_id INT PRIMARY KEY,\n    username VARCHAR(50),\n    password VARCHAR(50) DEFAULT '123456',\n    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n);<\/pre>\n<p>\u4ee5\u4e0a\u662fMySQL\u4e2d\u5e38\u7528\u7684\u7ea6\u675f\u7c7b\u578b\u53ca\u5176\u4f7f\u7528\u65b9\u6cd5\u7684\u4ecb\u7ecd\u3002\u4f7f\u7528\u7ea6\u675f\u53ef\u4ee5\u786e\u4fdd\u6570\u636e\u5e93\u7684\u6570\u636e\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u3002\u901a\u8fc7\u5408\u7406\u5730\u4f7f\u7528\u7ea6\u675f\uff0c\u53ef\u4ee5\u51cf\u5c11\u9519\u8bef\u548c\u4e0d\u4e00\u81f4\u7684\u6570\u636e\uff0c\u5e76\u63d0\u9ad8\u6570\u636e\u5e93\u7684\u6548\u7387\u548c\u53ef\u9760\u6027\u3002\u5e0c\u671b\u672c\u6587\u80fd\u591f\u5e2e\u52a9\u4f60\u7406\u89e3\u548c\u8fd0\u7528MySQL\u7684\u7ea6\u675f\u529f\u80fd\u3002<\/p>\n<p>\u4eca\u5929\u5173\u4e8e\u300a\u6df1\u5165\u4e86\u89e3MySQL\u7684\u7ea6\u675f\u7ea6\u675f\u300b\u7684\u5185\u5bb9\u5c31\u4ecb\u7ecd\u5230\u8fd9\u91cc\u4e86\uff0c\u662f\u4e0d\u662f\u5b66\u8d77\u6765\u4e00\u76ee\u4e86\u7136\uff01\u60f3\u8981\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u5185\u5bb9\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u4e86\u89e3MySQL\u7684\u7ea6\u675f\u7ea6\u675f \u73cd&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-199672","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199672","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=199672"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199672\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199672"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199672"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}