{"id":5721,"date":"2024-11-14T10:48:23","date_gmt":"2024-11-14T02:48:23","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5721\/"},"modified":"2024-11-14T10:48:23","modified_gmt":"2024-11-14T02:48:23","slug":"sql%e4%b8%8d%e7%ad%89%e4%ba%8e%e6%9f%90%e4%b8%aa%e5%80%bc%e6%80%8e%e4%b9%88%e5%86%99","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5721\/","title":{"rendered":"sql\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u503c\u600e\u4e48\u5199"},"content":{"rendered":"<blockquote><p>\n  sql \u4e2d\u4f7f\u7528\u4e0d\u7b49\u53f7\u8fd0\u7b97\u7b26\uff08!=\uff09\u67e5\u8be2\u4e0d\u7b49\u4e8e\u7279\u5b9a\u503c\u7684\u8bb0\u5f55\uff0c\u8be5\u8fd0\u7b97\u7b26\u6307\u793a\u5217\u503c\u4e0d\u7b49\u4e8e\u6307\u5b9a\u503c\u3002\u4ee5\u4e0b\u6b65\u9aa4\u63d0\u4f9b\u67e5\u8be2\u8be6\u60c5\uff1a\u4f7f\u7528 select * from table_name \u67e5\u8be2\u6307\u5b9a\u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\u3002\u4f7f\u7528 where \u5b50\u53e5\u6307\u5b9a\u5217\u540d\u548c\u503c\u4e4b\u95f4\u7684\u4e0d\u7b49\u5173\u7cfb\uff0c\u683c\u5f0f\u4e3a\uff1acolumn_name != value\u3002\u5982\u679c\u9700\u8981\u67e5\u8be2\u591a\u4e2a\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528 or \u8fd0\u7b97\u7b26\u7ec4\u5408\u5b83\u4eec\u3002\u8981\u67e5\u8be2\u4e0d\u4e3a null \u7684\u8bb0\u5f55\uff0c\u8bf7\u4f7f\u7528 is not null \u8fd0\u7b97\u7b26\u3002\u5b50\u67e5\u8be2\u4e5f\u53ef\u4ee5\u7528\u4f5c\u4e0d\u7b49\u5173\u7cfb\u4e2d\u7684\u503c\u3002\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202405\/30\/2024053021215125607.jpg\" class=\"aligncenter\" title=\"sql\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u503c\u600e\u4e48\u5199\u63d2\u56fe\" alt=\"sql\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u503c\u600e\u4e48\u5199\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u7279\u5b9a\u503c\u7684\u8bb0\u5f55<\/strong><\/p>\n<p>\u5728 SQL \u4e2d\uff0c\u4f7f\u7528\u4e0d\u7b49\u53f7\u8fd0\u7b97\u7b26\uff08!=\uff09\u6765\u786e\u5b9a\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u7279\u5b9a\u503c\u7684\u8bb0\u5f55\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528 != \u8fd0\u7b97\u7b26\u7684\u793a\u4f8b\uff1a<\/p>\n<p><strong>\u8bed\u6cd5\uff1a<\/strong><\/p>\n<pre>SELECT * FROM table_name\nWHERE column_name != value;<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n<pre>SELECT * FROM customers\nWHERE age != 30;<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u6b64\u67e5\u8be2\u5c06\u4ece &#8220;customers&#8221; \u8868\u4e2d\u9009\u62e9\u6240\u6709\u5e74\u9f84\u4e0d\u7b49\u4e8e 30 \u7684\u8bb0\u5f55\u3002<\/p>\n<p><strong>\u5176\u4ed6\u7528\u6cd5\uff1a<\/strong><\/p>\n<ul>\n<li> <strong>\u4f7f\u7528\u591a\u4e2a\u503c\uff1a<\/strong>\u53ef\u4ee5\u4f7f\u7528 OR \u8fd0\u7b97\u7b26\u5c06\u591a\u4e2a\u503c\u7ec4\u5408\u6210\u4e00\u4e2a\u67e5\u8be2\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>SELECT * FROM products\nWHERE price != 100 OR price != 150;<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u6b64\u67e5\u8be2\u5c06\u4ece &#8220;products&#8221; \u8868\u4e2d\u9009\u62e9\u6240\u6709\u4ef7\u683c\u4e0d\u7b49\u4e8e 100 \u6216 150 \u7684\u8bb0\u5f55\u3002<\/p>\n<ul>\n<li> <strong>\u4f7f\u7528 NULL \u503c\uff1a<\/strong>NULL \u503c\u8868\u793a\u4e00\u4e2a\u672a\u77e5\u6216\u4e0d\u5b58\u5728\u7684\u503c\u3002\u53ef\u4ee5\u4f7f\u7528 IS NOT NULL \u8fd0\u7b97\u7b26\u6765\u67e5\u8be2\u4e0d\u4e3a NULL \u7684\u8bb0\u5f55\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>SELECT * FROM orders\nWHERE order_date IS NOT NULL;<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u6b64\u67e5\u8be2\u5c06\u4ece &#8220;orders&#8221; \u8868\u4e2d\u9009\u62e9\u6240\u6709\u8ba2\u5355\u65e5\u671f\u5df2\u77e5\u7684\u8bb0\u5f55\u3002<\/p>\n<ul>\n<li> <strong>\u4f7f\u7528\u5b50\u67e5\u8be2\uff1a<\/strong>\u53ef\u4ee5\u5c06\u5b50\u67e5\u8be2\u7528\u4f5c != \u8fd0\u7b97\u7b26\u4e2d\u7684\u503c\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre>SELECT * FROM employees\nWHERE salary != (SELECT MAX(salary) FROM employees);<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u6b64\u67e5\u8be2\u5c06\u4ece &#8220;employees&#8221; \u8868\u4e2d\u9009\u62e9\u6240\u6709\u85aa\u6c34\u4e0d\u7b49\u4e8e\u8868\u4e2d\u6700\u9ad8\u85aa\u6c34\u7684\u8bb0\u5f55\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fsql\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u503c\u600e\u4e48\u5199\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>sql \u4e2d\u4f7f\u7528\u4e0d\u7b49\u53f7\u8fd0\u7b97\u7b26\uff08!=\uff09\u67e5\u8be2\u4e0d\u7b49\u4e8e\u7279\u5b9a\u503c\u7684\u8bb0\u5f55\uff0c\u8be5\u8fd0\u7b97\u7b26\u6307\u793a\u5217\u503c\u4e0d\u7b49\u4e8e\u6307\u5b9a\u503c\u3002\u4ee5\u4e0b\u6b65\u9aa4\u63d0\u4f9b\u67e5\u8be2\u8be6\u60c5\uff1a\u4f7f\u7528 select * from table_name \u67e5\u8be2\u6307\u5b9a\u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\u3002\u4f7f\u7528 where \u5b50\u53e5\u6307\u5b9a\u5217\u540d\u548c\u503c\u4e4b\u95f4\u7684\u4e0d\u7b49\u5173\u7cfb\uff0c\u683c\u5f0f\u4e3a\uff1acolumn_name != value\u3002\u5982\u679c\u9700\u8981\u67e5\u8be2\u591a\u4e2a\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528 or \u8fd0\u7b97\u7b26\u7ec4\u5408\u5b83\u4eec\u3002\u8981\u67e5\u8be2\u4e0d\u4e3a null \u7684\u8bb0\u5f55\uff0c\u8bf7\u4f7f\u7528 is not null \u8fd0\u7b97\u7b26\u3002\u5b50\u67e5\u8be2\u4e5f\u53ef\u4ee5\u7528\u4f5c\u4e0d\u7b49\u5173\u7cfb\u4e2d\u7684\u503c\u3002 \u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u7279\u5b9a\u503c\u7684\u8bb0\u5f55 \u5728 SQL \u4e2d\uff0c\u4f7f\u7528\u4e0d\u7b49\u53f7\u8fd0\u7b97\u7b26\uff08!=\uff09\u6765\u786e\u5b9a\u4e0d\u7b49\u4e8e\u67d0\u4e2a\u7279\u5b9a\u503c\u7684\u8bb0\u5f55\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528 != \u8fd0\u7b97\u7b26\u7684\u793a\u4f8b\uff1a \u8bed\u6cd5\uff1a SELECT * FROM table_name WHERE column_name != value; \u767b\u5f55\u540e\u590d\u5236 \u793a\u4f8b\uff1a SELECT * FROM customers WHERE age != 30; \u767b\u5f55\u540e\u590d\u5236 \u6b64\u67e5\u8be2\u5c06\u4ece &#8220;customers&#8221; \u8868\u4e2d\u9009\u62e9\u6240\u6709\u5e74\u9f84\u4e0d\u7b49\u4e8e 30 \u7684\u8bb0\u5f55\u3002 \u5176\u4ed6\u7528\u6cd5\uff1a \u4f7f\u7528\u591a\u4e2a\u503c\uff1a\u53ef\u4ee5\u4f7f\u7528 OR [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-5721","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5721","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=5721"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5721\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5721"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5721"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5721"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}