{"id":6954,"date":"2024-11-14T12:39:35","date_gmt":"2024-11-14T04:39:35","guid":{"rendered":"https:\/\/fwq.ai\/blog\/6954\/"},"modified":"2024-11-14T12:39:35","modified_gmt":"2024-11-14T04:39:35","slug":"%e5%a6%82%e4%bd%95%e6%a0%b9%e6%8d%ae%e6%9d%a1%e4%bb%b6%e5%b0%86%e5%a4%9a%e4%b8%aa%e5%ad%97%e6%ae%b5%e7%bb%84%e5%90%88%e6%88%90%e6%96%b0%e5%ad%97%e6%ae%b5%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/6954\/","title":{"rendered":"\u5982\u4f55\u6839\u636e\u6761\u4ef6\u5c06\u591a\u4e2a\u5b57\u6bb5\u7ec4\u5408\u6210\u65b0\u5b57\u6bb5\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/173017369875887.jpg\" class=\"aligncenter\" title=\"\u5982\u4f55\u6839\u636e\u6761\u4ef6\u5c06\u591a\u4e2a\u5b57\u6bb5\u7ec4\u5408\u6210\u65b0\u5b57\u6bb5\uff1f\u63d2\u56fe\" alt=\"\u5982\u4f55\u6839\u636e\u6761\u4ef6\u5c06\u591a\u4e2a\u5b57\u6bb5\u7ec4\u5408\u6210\u65b0\u5b57\u6bb5\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u5c06\u591a\u4e2a\u5b57\u6bb5\u7ec4\u5408\u6210\u65b0\u5b57\u6bb5\uff1f<\/strong><\/p>\n<p>\u8003\u8651\u4e00\u4e2a\u5305\u542b\u4ee5\u4e0b\u6570\u636e\u7684\u8868\uff1a<\/p>\n<pre>+------+---------+---------+\n| id   | \u4ef7\u683c1   | \u4ef7\u683c2   |\n+------+---------+---------+\n| 1    | 3.5     | 3.6     |\n| 2    | 2.1     | null    |\n| 3    | 2.35    | 2       |\n| 4    | 3.2     | null    |\n+------+---------+---------+<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p><strong>\u9700\u6c42\uff1a<\/strong>\u5b9a\u4e49 \u5b57\u6bb5\uff0c\u89c4\u5219\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>\u5982\u679c\u6709 \uff0c\u5219 \u7b49\u4e8e \u3002<\/li>\n<li>\u5426\u5219 \u7b49\u4e8e \u3002<\/li>\n<\/ul>\n<p><strong>\u5982\u4f55\u5b9e\u73b0\uff1f<\/strong><\/p>\n<p>\u4f7f\u7528\u4ee5\u4e0b sql \u67e5\u8be2\u83b7\u53d6 \u5b57\u6bb5\uff1a<\/p>\n<pre>select id, if (\u4ef7\u683c2 is not null, \u4ef7\u683c2\uff0c\u4ef7\u683c1) as price<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p><strong>\u89e3\u6790\uff1a<\/strong><\/p>\n<ul>\n<li>if() \u51fd\u6570\u7528\u4e8e\u6839\u636e\u6761\u4ef6\u5224\u65ad\u548c\u8fd4\u56de\u4e0d\u540c\u503c\u3002<\/li>\n<li>if (\u4ef7\u683c2 is not null, \u4ef7\u683c2\uff0c\u4ef7\u683c1)\uff1a\u5982\u679c \u4e0d\u4e3a null\uff0c\u5219\u8fd4\u56de \uff1b\u5426\u5219\u8fd4\u56de \u3002<\/li>\n<\/ul>\n<p><strong>\u7ed3\u679c\uff1a<\/strong><\/p>\n<pre>+---------+-----+\n| ID   | \u4ef7\u683c |\n+---------+-----+\n| 1    | 3.6 |\n| 2    | 2.1 |\n| 3    | 2   |\n| 4    | 3.2 |\n+---------+-----+<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u5982\u4f55\u6839\u636e\u6761\u4ef6\u5c06\u591a\u4e2a\u5b57\u6bb5\u7ec4\u5408\u6210\u65b0\u5b57\u6bb5\uff1f\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>\u5982\u4f55\u5c06\u591a\u4e2a\u5b57\u6bb5\u7ec4\u5408\u6210\u65b0\u5b57\u6bb5\uff1f \u8003\u8651\u4e00\u4e2a\u5305\u542b\u4ee5\u4e0b\u6570\u636e\u7684\u8868\uff1a +&#8212;&#8212;+&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;+ | id | \u4ef7\u683c1 | \u4ef7\u683c2 | +&#8212;&#8212;+&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;+ | 1 | 3.5 | 3.6 | | 2 | 2.1 | null | | 3 | 2.35 | 2 | | 4 | 3.2 | null | +&#8212;&#8212;+&#8212;&#8212;&#8212;+&#8212;&#8212;&#8212;+ \u767b\u5f55\u540e\u590d\u5236 \u9700\u6c42\uff1a\u5b9a\u4e49 \u5b57\u6bb5\uff0c\u89c4\u5219\u5982\u4e0b\uff1a \u5982\u679c\u6709 \uff0c\u5219 \u7b49\u4e8e \u3002 \u5426\u5219 \u7b49\u4e8e \u3002 \u5982\u4f55\u5b9e\u73b0\uff1f \u4f7f\u7528\u4ee5\u4e0b sql \u67e5\u8be2\u83b7\u53d6 \u5b57\u6bb5\uff1a [&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-6954","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6954","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=6954"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6954\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=6954"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=6954"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=6954"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}