{"id":179848,"date":"2024-11-09T05:18:21","date_gmt":"2024-11-08T21:18:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179848\/"},"modified":"2024-11-09T05:18:22","modified_gmt":"2024-11-08T21:18:22","slug":"%e5%a6%82%e4%bd%95%e5%9c%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e9%81%8e%e6%bf%be%e4%b8%8d%e7%82%ba%e7%a9%ba%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad-where-not-null","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179848\/","title":{"rendered":"\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u904e\u6ffe\u4e0d\u70ba\u7a7a\u7684\u6578\u64da\uff1f (\u6578\u64da\u5eab\u4e2d where not null)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e5%9c%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e9%81%8e%e6%bf%be%e4%b8%8d%e7%82%ba%e7%a9%ba%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad-where-not-null-VpBwQtRzgt\">\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u904e\u6ffe\u4e0d\u70ba\u7a7a\u7684\u6578\u64da\uff1f (\u6578\u64da\u5eab\u4e2d where not null)<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u904e\u6ffe\u4e0d\u70ba\u7a7a\u7684\u6578\u64da\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002\u9019\u4e0d\u50c5\u6709\u52a9\u65bc\u63d0\u9ad8\u67e5\u8a62\u7684\u6548\u7387\uff0c\u9084\u80fd\u78ba\u4fdd\u6211\u5011\u7372\u53d6\u7684\u6578\u64da\u662f\u5b8c\u6574\u4e14\u6709\u610f\u7fa9\u7684\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u4f7f\u7528 SQL \u8a9e\u53e5\u4f86\u904e\u6ffe\u4e0d\u70ba\u7a7a\u7684\u6578\u64da\uff0c\u7279\u5225\u662f\u4f7f\u7528 <code>WHERE NOT NULL<\/code> \u689d\u4ef6\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-null-%e5%80%bc%ef%bc%9f-VpBwQtRzgt\">\u4ec0\u9ebc\u662f NULL \u503c\uff1f<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\uff0c<code>NULL<\/code> \u503c\u8868\u793a\u7f3a\u5931\u6216\u672a\u77e5\u7684\u6578\u64da\u3002\u9019\u610f\u5473\u8457\u8a72\u5b57\u6bb5\u6c92\u6709\u4efb\u4f55\u503c\uff0c\u8207\u7a7a\u5b57\u7b26\u4e32\u6216\u96f6\u4e0d\u540c\u3002NULL \u503c\u5728\u6578\u64da\u5eab\u4e2d\u662f\u975e\u5e38\u91cd\u8981\u7684\uff0c\u56e0\u70ba\u5b83\u5011\u53ef\u4ee5\u5f71\u97ff\u67e5\u8a62\u7684\u7d50\u679c\u548c\u6578\u64da\u7684\u5b8c\u6574\u6027\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-where-not-null-%e9%81%8e%e6%bf%be%e6%95%b8%e6%93%9a-VpBwQtRzgt\">\u4f7f\u7528 WHERE NOT NULL \u904e\u6ffe\u6578\u64da<\/h2>\n<p>\u7576\u6211\u5011\u9700\u8981\u67e5\u8a62\u67d0\u500b\u5b57\u6bb5\u4e0d\u70ba NULL \u7684\u6578\u64da\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>WHERE NOT NULL<\/code> \u689d\u4ef6\u3002\u9019\u6a23\u53ef\u4ee5\u904e\u6ffe\u6389\u6240\u6709\u5305\u542b NULL \u503c\u7684\u8a18\u9304\uff0c\u50c5\u8fd4\u56de\u6709\u6548\u7684\u6578\u64da\u3002<\/p>\n<h3 id=\"%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-VpBwQtRzgt\">\u57fa\u672c\u8a9e\u6cd5<\/h3>\n<pre><code>SELECT column1, column2, ...\nFROM table_name\nWHERE column_name IS NOT NULL;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>column_name<\/code> \u662f\u6211\u5011\u5e0c\u671b\u904e\u6ffe\u7684\u5b57\u6bb5\u540d\uff0c<code>table_name<\/code> \u662f\u6578\u64da\u8868\u7684\u540d\u7a31\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b-VpBwQtRzgt\">\u7bc4\u4f8b<\/h3>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>employees<\/code> \u7684\u6578\u64da\u8868\uff0c\u8a72\u8868\u5305\u542b\u4ee5\u4e0b\u5b57\u6bb5\uff1a<\/p>\n<ul>\n<li><code>id<\/code><\/li>\n<li><code>name<\/code><\/li>\n<li><code>email<\/code><\/li>\n<li><code>phone<\/code><\/li>\n<\/ul>\n<p>\u5982\u679c\u6211\u5011\u60f3\u67e5\u8a62\u6240\u6709\u64c1\u6709\u6709\u6548\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u7684\u54e1\u5de5\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u8a9e\u53e5\uff1a<\/p>\n<pre><code>SELECT id, name, email\nFROM employees\nWHERE email IS NOT NULL;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u4e0d\u70ba NULL \u7684\u54e1\u5de5\u8a18\u9304\u3002<\/p>\n<h2 id=\"%e5%a4%9a%e6%a2%9d%e4%bb%b6%e9%81%8e%e6%bf%be-VpBwQtRzgt\">\u591a\u689d\u4ef6\u904e\u6ffe<\/h2>\n<p>\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u6211\u5011\u7d93\u5e38\u9700\u8981\u6839\u64da\u591a\u500b\u689d\u4ef6\u4f86\u904e\u6ffe\u6578\u64da\u3002\u9019\u6642\u53ef\u4ee5\u7d50\u5408\u4f7f\u7528 <code>AND<\/code> \u6216 <code>OR<\/code> \u4f86\u9054\u6210\u76ee\u7684\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b-VpBwQtRzgt\">\u7bc4\u4f8b<\/h3>\n<p>\u5982\u679c\u6211\u5011\u5e0c\u671b\u67e5\u8a62\u6240\u6709\u64c1\u6709\u6709\u6548\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u4e14\u96fb\u8a71\u865f\u78bc\u4e0d\u70ba NULL \u7684\u54e1\u5de5\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u8a9e\u53e5\uff1a<\/p>\n<pre><code>SELECT id, name, email, phone\nFROM employees\nWHERE email IS NOT NULL AND phone IS NOT NULL;<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u96fb\u5b50\u90f5\u4ef6\u548c\u96fb\u8a71\u865f\u78bc\u5747\u6709\u6548\u7684\u54e1\u5de5\u8a18\u9304\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-VpBwQtRzgt\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u4f7f\u7528 <code>WHERE NOT NULL<\/code> \u9032\u884c\u904e\u6ffe\u6642\uff0c\u9700\u6ce8\u610f\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li>NULL \u503c\u7684\u8655\u7406\uff1a\u5728\u9032\u884c\u6578\u64da\u5206\u6790\u6642\uff0c\u5fc5\u9808\u8003\u616e NULL \u503c\u7684\u5b58\u5728\uff0c\u56e0\u70ba\u5b83\u5011\u53ef\u80fd\u6703\u5f71\u97ff\u7d71\u8a08\u7d50\u679c\u3002<\/li>\n<li>\u6027\u80fd\u8003\u91cf\uff1a\u5728\u5927\u578b\u6578\u64da\u8868\u4e2d\uff0c\u904e\u6ffe NULL \u503c\u53ef\u80fd\u6703\u5f71\u97ff\u67e5\u8a62\u6027\u80fd\uff0c\u5efa\u8b70\u5728\u8a2d\u8a08\u6578\u64da\u8868\u6642\u5408\u7406\u898f\u5283\u5b57\u6bb5\u7684 NULL \u5c6c\u6027\u3002<\/li>\n<li>\u6578\u64da\u5b8c\u6574\u6027\uff1a\u78ba\u4fdd\u5728\u6578\u64da\u63d2\u5165\u6642\u9032\u884c\u5fc5\u8981\u7684\u6aa2\u67e5\uff0c\u4ee5\u907f\u514d\u4e0d\u5fc5\u8981\u7684 NULL \u503c\u51fa\u73fe\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-VpBwQtRzgt\">\u7e3d\u7d50<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\u904e\u6ffe\u4e0d\u70ba\u7a7a\u7684\u6578\u64da\u662f\u4e00\u500b\u57fa\u672c\u800c\u91cd\u8981\u7684\u64cd\u4f5c\u3002\u901a\u904e\u4f7f\u7528 <code>WHERE NOT NULL<\/code> \u689d\u4ef6\uff0c\u6211\u5011\u53ef\u4ee5\u6709\u6548\u5730\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\uff0c\u5f9e\u800c\u63d0\u9ad8\u6578\u64da\u67e5\u8a62\u7684\u6e96\u78ba\u6027\u548c\u6548\u7387\u3002\u7121\u8ad6\u662f\u5728\u65e5\u5e38\u7684\u6578\u64da\u7ba1\u7406\u9084\u662f\u8907\u96dc\u7684\u6578\u64da\u5206\u6790\u4e2d\uff0c\u638c\u63e1\u9019\u4e00\u6280\u5de7\u90fd\u662f\u975e\u5e38\u5fc5\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\uff0c\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u5176\u4ed6\u61c9\u7528\u5834\u666f\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u4f7f\u7528 WHERE NOT NULL \u689d\u4ef6\u904e\u6ffe\u4e0d\u70ba\u7a7a\u7684\u6578\u64da\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\u8207\u6578\u64da\u6e96\u78ba\u6027\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-179848","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179848","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=179848"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179848\/revisions"}],"predecessor-version":[{"id":179849,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179848\/revisions\/179849"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179848"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179848"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179848"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}