{"id":6356,"date":"2024-07-18T20:02:14","date_gmt":"2024-07-18T12:02:14","guid":{"rendered":"https:\/\/t.n-years.com\/?p=6356"},"modified":"2024-07-18T20:02:29","modified_gmt":"2024-07-18T12:02:29","slug":"%e5%85%b3%e7%b3%bb%e5%9e%8b%e6%95%b0%e6%8d%ae%e5%ba%93%e8%ae%be%e8%ae%a1%e8%8c%83%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/t.n-years.com\/?p=6356","title":{"rendered":"\u5173\u7cfb\u578b\u6570\u636e\u5e93\u8bbe\u8ba1\u8303\u5f0f"},"content":{"rendered":"<p>\u6570\u636e\u5e93\u8bbe\u8ba1\u7684\u8303\u5f0f\uff08Normal Forms\uff09\u662f\u4e00\u4e9b\u89c4\u8303\u5316\u7684\u89c4\u5219\uff0c\u7528\u4e8e\u7ec4\u7ec7\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\uff0c\u4ee5\u51cf\u5c11\u5197\u4f59\u3001\u6d88\u9664\u5f02\u5e38\u3001\u63d0\u9ad8\u6570\u636e\u4e00\u81f4\u6027\u3002\u4e0b\u9762\u662f\u51e0\u5927\u5e38\u89c1\u7684\u6570\u636e\u5e93\u8303\u5f0f\uff1a<\/p>\n<h3>\u7b2c\u4e00\u8303\u5f0f (1NF: First Normal Form)<\/h3>\n<p><strong>\u8981\u6c42<\/strong>\uff1a<\/p>\n<ul>\n<li>\u6240\u6709\u8868\u4e2d\u7684\u5b57\u6bb5\u5fc5\u987b\u662f\u539f\u5b50\u6027\u7684\uff0c\u5373\u6bcf\u4e2a\u5b57\u6bb5\u53ea\u80fd\u5305\u542b\u4e00\u4e2a\u503c\uff0c\u800c\u4e0d\u80fd\u5305\u542b\u4e00\u7ec4\u503c\u6216\u5217\u8868\u3002<\/li>\n<li>\u8868\u4e2d\u6bcf\u4e00\u5217\u5fc5\u987b\u662f\u5355\u503c\u5c5e\u6027\uff0c\u4e0d\u53ef\u518d\u5206\u3002<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>\u4e3e\u4f8b<\/strong>\uff1a<br \/>\n\u5047\u8bbe\u6709\u4e00\u4e2a\u5ba2\u6237\u8868\uff1a<\/th>\n<th>CustomerID<\/th>\n<th>CustomerName<\/th>\n<th>PhoneNumbers<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>Alice<\/td>\n<td>123-4567, 234-5678<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u8fd9\u91cc <code>PhoneNumbers<\/code> \u5217\u8fdd\u53cd\u4e86\u7b2c\u4e00\u8303\u5f0f\uff0c\u56e0\u4e3a\u5b83\u5305\u542b\u591a\u4e2a\u503c\u3002\u5c06\u5176\u89c4\u8303\u5316\u4e3a\u7b2c\u4e00\u8303\u5f0f\uff1a<\/th>\n<th>CustomerID<\/th>\n<th>CustomerName<\/th>\n<th>PhoneNumber<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>Alice<\/td>\n<td>123-4567<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>Alice<\/td>\n<td>234-5678<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u7b2c\u4e8c\u8303\u5f0f (2NF: Second Normal Form)<\/h3>\n<p><strong>\u8981\u6c42<\/strong>\uff1a<\/p>\n<ul>\n<li>\u6ee1\u8db3\u7b2c\u4e00\u8303\u5f0f\u3002<\/li>\n<li>\u8868\u4e2d\u7684\u6bcf\u4e2a\u975e\u4e3b\u952e\u5217\u90fd\u5fc5\u987b\u5b8c\u5168\u4f9d\u8d56\u4e8e\u4e3b\u952e\uff08\u5373\u4e0d\u80fd\u6709\u90e8\u5206\u4f9d\u8d56\uff09\u3002<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>\u4e3e\u4f8b<\/strong>\uff1a<br \/>\n\u5047\u8bbe\u6709\u4e00\u4e2a\u8ba2\u5355\u8868\uff1a<\/th>\n<th>OrderID<\/th>\n<th>ProductID<\/th>\n<th>ProductName<\/th>\n<th>Quantity<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>101<\/td>\n<td>Widget<\/td>\n<td>10<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>102<\/td>\n<td>Gadget<\/td>\n<td>5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u8fd9\u91cc <code>ProductName<\/code> \u4f9d\u8d56\u4e8e <code>ProductID<\/code>\uff0c\u800c\u4e0d\u662f <code>OrderID<\/code>\u3002\u5c06\u5176\u89c4\u8303\u5316\u4e3a\u7b2c\u4e8c\u8303\u5f0f\uff1a<br \/>\n<strong>\u8ba2\u5355\u8868<\/strong>\uff1a<\/th>\n<th>OrderID<\/th>\n<th>ProductID<\/th>\n<th>Quantity<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>101<\/td>\n<td>10<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>102<\/td>\n<td>5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th><strong>\u4ea7\u54c1\u8868<\/strong>\uff1a<\/th>\n<th>ProductID<\/th>\n<th>ProductName<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>101<\/td>\n<td>Widget<\/td>\n<\/tr>\n<tr>\n<td>102<\/td>\n<td>Gadget<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u7b2c\u4e09\u8303\u5f0f (3NF: Third Normal Form)<\/h3>\n<p><strong>\u8981\u6c42<\/strong>\uff1a<\/p>\n<ul>\n<li>\u6ee1\u8db3\u7b2c\u4e8c\u8303\u5f0f\u3002<\/li>\n<li>\u8868\u4e2d\u7684\u6bcf\u4e2a\u975e\u4e3b\u952e\u5217\u5fc5\u987b\u76f4\u63a5\u4f9d\u8d56\u4e8e\u4e3b\u952e\uff0c\u800c\u4e0d\u80fd\u4f9d\u8d56\u4e8e\u5176\u4ed6\u975e\u4e3b\u952e\u5217\uff08\u5373\u4e0d\u80fd\u6709\u4f20\u9012\u4f9d\u8d56\uff09\u3002<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>\u4e3e\u4f8b<\/strong>\uff1a<br \/>\n\u5047\u8bbe\u6709\u4e00\u4e2a\u5b66\u751f\u8868\uff1a<\/th>\n<th>StudentID<\/th>\n<th>StudentName<\/th>\n<th>DepartmentID<\/th>\n<th>DepartmentName<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>Alice<\/td>\n<td>10<\/td>\n<td>Computer Science<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Bob<\/td>\n<td>20<\/td>\n<td>Mathematics<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u8fd9\u91cc <code>DepartmentName<\/code> \u4f9d\u8d56\u4e8e <code>DepartmentID<\/code>\uff0c\u800c <code>DepartmentID<\/code> \u53c8\u4f9d\u8d56\u4e8e <code>StudentID<\/code>\u3002\u5c06\u5176\u89c4\u8303\u5316\u4e3a\u7b2c\u4e09\u8303\u5f0f\uff1a<br \/>\n<strong>\u5b66\u751f\u8868<\/strong>\uff1a<\/th>\n<th>StudentID<\/th>\n<th>StudentName<\/th>\n<th>DepartmentID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>Alice<\/td>\n<td>10<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Bob<\/td>\n<td>20<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th><strong>\u90e8\u95e8\u8868<\/strong>\uff1a<\/th>\n<th>DepartmentID<\/th>\n<th>DepartmentName<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>10<\/td>\n<td>Computer Science<\/td>\n<\/tr>\n<tr>\n<td>20<\/td>\n<td>Mathematics<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>BCNF (Boyce-Codd Normal Form)<\/h3>\n<p><strong>\u8981\u6c42<\/strong>\uff1a<\/p>\n<ul>\n<li>\u6ee1\u8db3\u7b2c\u4e09\u8303\u5f0f\u3002<\/li>\n<li>\u5bf9\u4e8e\u6bcf\u4e2a\u975e\u5e73\u51e1\u7684\u51fd\u6570\u4f9d\u8d56 X -&gt; Y\uff0cX \u5fc5\u987b\u662f\u8d85\u952e\uff08superkey\uff09\u3002<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>\u4e3e\u4f8b<\/strong>\uff1a<br \/>\n\u5047\u8bbe\u6709\u4e00\u4e2a\u8bfe\u7a0b\u8868\uff1a<\/th>\n<th>CourseID<\/th>\n<th>Instructor<\/th>\n<th>Classroom<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>Prof. A<\/td>\n<td>Room 101<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Prof. B<\/td>\n<td>Room 102<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u5982\u679c\u4e00\u4e2a\u6559\u5ba4\u53ea\u80fd\u7531\u4e00\u4e2a\u6559\u6388\u6559\u6388\uff0c\u5e76\u4e14\u4e00\u4e2a\u6559\u6388\u53ea\u80fd\u5728\u4e00\u4e2a\u6559\u5ba4\u6388\u8bfe\uff0c\u8fd9\u91cc\u5b58\u5728\u4e00\u4e2a\u4f9d\u8d56\u5173\u7cfb <code>Classroom -&gt; Instructor<\/code>\u3002\u5c06\u5176\u89c4\u8303\u5316\u4e3a BCNF\uff1a<br \/>\n<strong>\u8bfe\u7a0b\u8868<\/strong>\uff1a<\/th>\n<th>CourseID<\/th>\n<th>Instructor<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>Prof. A<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Prof. B<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th><strong>\u6559\u5ba4\u8868<\/strong>\uff1a<\/th>\n<th>Classroom<\/th>\n<th>Instructor<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Room 101<\/td>\n<td>Prof. A<\/td>\n<\/tr>\n<tr>\n<td>Room 102<\/td>\n<td>Prof. B<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u7b2c\u56db\u8303\u5f0f (4NF: Fourth Normal Form)<\/h3>\n<p><strong>\u8981\u6c42<\/strong>\uff1a<\/p>\n<ul>\n<li>\u6ee1\u8db3 BCNF\u3002<\/li>\n<li>\u4e0d\u5305\u542b\u591a\u503c\u4f9d\u8d56\uff08\u4e00\u4e2a\u5c5e\u6027\u4f9d\u8d56\u4e8e\u53e6\u4e00\u4e2a\u5c5e\u6027\u7684\u591a\u4e2a\u503c\uff09\u3002<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>\u4e3e\u4f8b<\/strong>\uff1a<br \/>\n\u5047\u8bbe\u6709\u4e00\u4e2a\u9879\u76ee\u8868\uff1a<\/th>\n<th>ProjectID<\/th>\n<th>EmployeeID<\/th>\n<th>SkillID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>101<\/td>\n<td>A<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>101<\/td>\n<td>B<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>102<\/td>\n<td>A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u8fd9\u91cc\u4e00\u4e2a\u9879\u76ee\u53ef\u4ee5\u6d89\u53ca\u591a\u4e2a\u5458\u5de5\uff0c\u4e00\u4e2a\u5458\u5de5\u53ef\u4ee5\u62e5\u6709\u591a\u9879\u6280\u80fd\uff0c\u5b58\u5728\u591a\u503c\u4f9d\u8d56\u3002\u5c06\u5176\u89c4\u8303\u5316\u4e3a\u7b2c\u56db\u8303\u5f0f\uff1a<br \/>\n<strong>\u9879\u76ee-\u5458\u5de5\u8868<\/strong>\uff1a<\/th>\n<th>ProjectID<\/th>\n<th>EmployeeID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>101<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>102<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th><strong>\u5458\u5de5-\u6280\u80fd\u8868<\/strong>\uff1a<\/th>\n<th>EmployeeID<\/th>\n<th>SkillID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>101<\/td>\n<td>A<\/td>\n<\/tr>\n<tr>\n<td>101<\/td>\n<td>B<\/td>\n<\/tr>\n<tr>\n<td>102<\/td>\n<td>A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u7b2c\u4e94\u8303\u5f0f (5NF: Fifth Normal Form)<\/h3>\n<p><strong>\u8981\u6c42<\/strong>\uff1a<\/p>\n<ul>\n<li>\u6ee1\u8db3\u7b2c\u56db\u8303\u5f0f\u3002<\/li>\n<li>\u6d88\u9664\u6240\u6709\u7684\u8fde\u63a5\u4f9d\u8d56\uff08Join Dependency\uff09\u3002<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th><strong>\u4e3e\u4f8b<\/strong>\uff1a<br \/>\n\u5047\u8bbe\u6709\u4e00\u4e2a\u4f9b\u5e94\u5546-\u96f6\u4ef6-\u9879\u76ee\u8868\uff1a<\/th>\n<th>SupplierID<\/th>\n<th>PartID<\/th>\n<th>ProjectID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>A<\/td>\n<td>X<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>B<\/td>\n<td>X<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>A<\/td>\n<td>Y<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>B<\/td>\n<td>Y<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u5c06\u5176\u89c4\u8303\u5316\u4e3a\u7b2c\u4e94\u8303\u5f0f\uff1a<br \/>\n<strong>\u4f9b\u5e94\u5546-\u96f6\u4ef6\u8868<\/strong>\uff1a<\/th>\n<th>SupplierID<\/th>\n<th>PartID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>A<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>B<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>A<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>B<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th><strong>\u96f6\u4ef6-\u9879\u76ee\u8868<\/strong>\uff1a<\/th>\n<th>PartID<\/th>\n<th>ProjectID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>A<\/td>\n<td>X<\/td>\n<\/tr>\n<tr>\n<td>B<\/td>\n<td>X<\/td>\n<\/tr>\n<tr>\n<td>A<\/td>\n<td>Y<\/td>\n<\/tr>\n<tr>\n<td>B<\/td>\n<td>Y<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th><strong>\u4f9b\u5e94\u5546-\u9879\u76ee\u8868<\/strong>\uff1a<\/th>\n<th>SupplierID<\/th>\n<th>ProjectID<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>X<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>Y<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u901a\u8fc7\u9075\u5faa\u8fd9\u4e9b\u8303\u5f0f\u89c4\u5219\uff0c\u53ef\u4ee5\u8bbe\u8ba1\u51fa\u66f4\u52a0\u5065\u58ee\u3001\u51cf\u5c11\u5197\u4f59\u4e14\u6613\u4e8e\u7ef4\u62a4\u7684\u6570\u636e\u5e93\u6a21\u578b\u3002\u6bcf\u4e2a\u8303\u5f0f\u90fd\u6709\u5176\u5e94\u7528\u573a\u666f\u548c\u9650\u5236\uff0c\u5b9e\u9645\u4e2d\u9700\u8981\u6839\u636e\u5177\u4f53\u9700\u6c42\u6765\u5e73\u8861\u89c4\u8303\u5316\u4e0e\u6027\u80fd\u4e4b\u95f4\u7684\u5173\u7cfb\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6570\u636e\u5e93\u8bbe\u8ba1\u7684\u8303\u5f0f\uff08Normal Forms\uff09\u662f\u4e00\u4e9b\u89c4\u8303\u5316\u7684\u89c4\u5219\uff0c\u7528\u4e8e\u7ec4\u7ec7\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\uff0c\u4ee5\u51cf\u5c11\u5197\u4f59\u3001\u6d88\u9664\u5f02\u5e38\u3001&#8230; <\/p>\n<div class=\"read-more navbutton\"><a href=\"https:\/\/t.n-years.com\/?p=6356\">\u9605\u8bfb\u66f4\u591a<i class=\"fa fa-angle-double-right\"><\/i><\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[123],"tags":[126],"class_list":["post-6356","post","type-post","status-publish","format-standard","hentry","category-123","tag-mysql"],"_links":{"self":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6356","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6356"}],"version-history":[{"count":1,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6356\/revisions"}],"predecessor-version":[{"id":6357,"href":"https:\/\/t.n-years.com\/index.php?rest_route=\/wp\/v2\/posts\/6356\/revisions\/6357"}],"wp:attachment":[{"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6356"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6356"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/t.n-years.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6356"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}