{"id":200985,"date":"2025-05-06T11:39:36","date_gmt":"2025-05-06T03:39:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200985\/"},"modified":"2025-05-06T11:39:36","modified_gmt":"2025-05-06T03:39:36","slug":"mysql-%e4%b8%ad-where-%e6%9d%a1%e4%bb%b6%e4%bb%85%e6%8c%87%e5%ae%9a%e5%ad%97%e6%ae%b5%ef%bc%8c%e4%b8%ba%e4%bd%95%e8%83%bd%e5%8c%b9%e9%85%8d%e7%89%b9%e5%ae%9a%e7%bb%93%e6%9e%9c%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200985\/","title":{"rendered":"MySQL \u4e2d where \u6761\u4ef6\u4ec5\u6307\u5b9a\u5b57\u6bb5\uff0c\u4e3a\u4f55\u80fd\u5339\u914d\u7279\u5b9a\u7ed3\u679c\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>MySQL \u4e2d where \u6761\u4ef6\u4ec5\u6307\u5b9a\u5b57\u6bb5\uff0c\u4e3a\u4f55\u80fd\u5339\u914d\u7279\u5b9a\u7ed3\u679c\uff1f<\/h1>\n<p>IT\u884c\u4e1a\u76f8\u5bf9\u4e8e\u4e00\u822c\u4f20\u7edf\u884c\u4e1a\uff0c\u53d1\u5c55\u66f4\u65b0\u901f\u5ea6\u66f4\u5feb\uff0c\u4e00\u65e6\u505c\u6b62\u4e86\u5b66\u4e60\uff0c\u5f88\u5feb\u5c31\u4f1a\u88ab\u884c\u4e1a\u6240\u6dd8\u6c70\u3002\u6240\u4ee5\u6211\u4eec\u9700\u8981\u8e0f\u8e0f\u5b9e\u5b9e\u7684\u4e0d\u65ad\u5b66\u4e60\uff0c\u7cbe\u8fdb\u81ea\u5df1\u7684\u6280\u672f\uff0c\u5c24\u5176\u662f\u521d\u5b66\u8005\u3002\u4eca\u5929\u4e3b\u673a\u5b9d\u8d1d\u7ed9\u5927\u5bb6\u6574\u7406\u4e86\u300aMySQL \u4e2d where \u6761\u4ef6\u4ec5\u6307\u5b9a\u5b57\u6bb5\uff0c\u4e3a\u4f55\u80fd\u5339\u914d\u7279\u5b9a\u7ed3\u679c\uff1f\u300b\uff0c\u804a\u804a\uff0c\u6211\u4eec\u4e00\u8d77\u6765\u770b\u770b\u5427\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241124\/17324291156742c53b5dd0d.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>mysql \u4e2d where \u6761\u4ef6\u4e2d\u4ec5\u6709\u5b57\u6bb5\u7684\u7591\u60d1<\/strong><\/p>\n<p>\u5728 mysql \u4e2d\uff0c\u6709\u4e00\u4e2a\u72ec\u7279\u7684\u67e5\u8be2\u73b0\u8c61\uff0c\u5f53\u5728 where \u6761\u4ef6\u4e2d\u4ec5\u6307\u5b9a\u5b57\u6bb5\u800c\u672a\u6307\u5b9a\u5177\u4f53\u503c\u65f6\uff0c\u53ef\u4ee5\u8fd4\u56de\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\u7684\u7ed3\u679c\u3002\u4f8b\u5982\uff0c\u5728\u4ee5\u4e0b\u67e5\u8be2\u8bed\u53e5\u4e2d\uff1a<\/p>\n<pre>select id from users where id<\/pre>\n<p>\u5373\u4f7f where \u5b50\u53e5\u4e2d\u6ca1\u6709\u6307\u5b9a\u5177\u4f53\u503c\uff0c\u8be5\u67e5\u8be2\u4ecd\u4f1a\u8fd4\u56de\u7ed3\u679c\uff0c\u4f46\u4ec5\u9650\u4e8e id \u5b57\u6bb5\u4ee5\u6570\u5b57\u5f00\u5934\u7684\u8bb0\u5f55\uff0c\u800c\u5b57\u6bcd\u548c 0 \u5f00\u5934\u7684\u8bb0\u5f55\u4f1a\u88ab\u8fc7\u6ee4\u6389\u3002<\/p>\n<p><strong>mysql \u6587\u6863\u7684\u89e3\u91ca<\/strong><\/p>\n<p>\u6839\u636e mysql \u5b98\u65b9\u6587\u6863\uff0c\u5f53\u5728 where \u6761\u4ef6\u4e2d\u6307\u5b9a\u8868\u8fbe\u5f0f\u65f6\uff0c\u8868\u8fbe\u5f0f\u5fc5\u987b\u5bf9\u6bcf\u6761\u8981\u9009\u62e9\u7684\u884c\u8fd4\u56de true\uff1a<\/p>\n<pre>where_condition \u662f\u4e00\u4e2a\u8868\u8fbe\u5f0f\uff0c\u5bf9\u4e8e\u6bcf\u6761\u8981\u9009\u62e9\u7684\u884c\u6765\u8bf4\uff0c\u5176\u503c\u4e3a\u771f\u3002<\/pre>\n<p>\u6362\u53e5\u8bdd\u8bf4\uff0c\u5728\u6ca1\u6709\u6307\u5b9a\u5177\u4f53\u503c\u7684\u60c5\u51b5\u4e0b\uff0cwhere \u4e2d\u7684\u5b57\u6bb5\u81ea\u8eab\u88ab\u5f53\u4f5c\u4e00\u4e2a\u6761\u4ef6\uff0c\u5982\u679c\u8be5\u5b57\u6bb5\u7684\u503c\u53ef\u4ee5\u8f6c\u6362\u4e3a true\uff0c\u5219\u6ee1\u8db3\u8be5\u6761\u4ef6\u3002\u5bf9\u4e8e id \u5b57\u6bb5\u6765\u8bf4\uff0c\u6570\u5b57\u548c\u5b57\u7b26\u4e32\u7a7a\u503c\u90fd\u53ef\u4ee5\u8f6c\u6362\u4e3a true\uff0c\u800c\u5b57\u6bcd\u548c 0 \u5219\u4e0d\u80fd\uff0c\u56e0\u6b64\u53ea\u6709\u6570\u5b57\u5f00\u5934\u7684\u8bb0\u5f55\u624d\u4f1a\u88ab\u8fd4\u56de\u3002<\/p>\n<p><strong>\u8868\u8fbe\u5f0f\u7684\u6982\u5ff5<\/strong><\/p>\n<p>\u5728 mysql \u4e2d\uff0c\u8868\u8fbe\u5f0f\u53ef\u4ee5\u5305\u542b\u4efb\u4f55 mysql \u652f\u6301\u7684\u51fd\u6570\u548c\u64cd\u4f5c\u7b26\uff0c\u5305\u62ec\u903b\u8f91\u8fd0\u7b97\u7b26\u548c\u6bd4\u8f83\u8fd0\u7b97\u7b26\u3002\u5728 where \u6761\u4ef6\u4e2d\u4f7f\u7528\u5b57\u6bb5\u65f6\uff0c\u5b83\u4f1a\u88ab\u89c6\u4e3a\u4e00\u4e2a\u5e03\u5c14\u8868\u8fbe\u5f0f\uff0c\u5176\u503c\u4e3a true \u6216 false\u3002\u4f8b\u5982\uff1a<\/p>\n<pre>where id &gt; 0<\/pre>\n<p>\u8fd9\u4e2a\u6761\u4ef6\u7b49\u4e8e\u4ee5\u4e0b\u8868\u8fbe\u5f0f\uff1a<\/p>\n<pre>where id is not null and id &lt;&gt; \"\" and id &gt; 0<\/pre>\n<p>\u56e0\u6b64\uff0cid \u5b57\u6bb5\u88ab\u89c6\u4e3a\u4e00\u4e2a\u6761\u4ef6\uff0c\u5982\u679c\u5176\u503c\u5927\u4e8e 0 \u5219\u4e3a true\uff0c\u5426\u5219\u4e3a false\u3002<\/p>\n<p><strong>\u7ed3\u8bba<\/strong><\/p>\n<p>\u5728 mysql \u4e2d\uff0cwhere \u6761\u4ef6\u4e2d\u4ec5\u6709\u5b57\u6bb5\u7684\u67e5\u8be2\u73b0\u8c61\u662f\u56e0\u4e3a\u5b57\u6bb5\u672c\u8eab\u88ab\u5f53\u4f5c\u4e00\u4e2a\u8868\u8fbe\u5f0f\uff0c\u5176\u503c\u53ef\u4ee5\u8f6c\u6362\u4e3a true \u6216 false\u3002\u5bf9\u4e8e\u6570\u5b57\u5b57\u6bb5\uff0c\u6570\u5b57\u548c\u5b57\u7b26\u4e32\u7a7a\u503c\u53ef\u4ee5\u8f6c\u6362\u4e3a true\uff0c\u800c\u5b57\u6bcd\u548c 0 \u5219\u4e0d\u80fd\uff0c\u56e0\u6b64\u4ec5\u8fd4\u56de\u6570\u5b57\u5f00\u5934\u7684\u8bb0\u5f55\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u300aMySQL \u4e2d where \u6761\u4ef6\u4ec5\u6307\u5b9a\u5b57\u6bb5\uff0c\u4e3a\u4f55\u80fd\u5339\u914d\u7279\u5b9a\u7ed3\u679c\uff1f\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8e\u7684\u8d44\u6599\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>MySQL \u4e2d where \u6761\u4ef6&#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-200985","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200985","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=200985"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200985\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200985"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200985"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200985"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}