{"id":5702,"date":"2024-11-14T13:10:55","date_gmt":"2024-11-14T05:10:55","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5702\/"},"modified":"2024-11-14T13:10:55","modified_gmt":"2024-11-14T05:10:55","slug":"sql%e8%af%ad%e5%8f%a5%e6%8e%92%e5%ba%8f%e6%80%8e%e4%b9%88%e6%8e%92%e5%88%b00","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5702\/","title":{"rendered":"sql\u8bed\u53e5\u6392\u5e8f\u600e\u4e48\u6392\u52300"},"content":{"rendered":"

\n sql \u4e2d\u5c06\u503c\u6392\u5e8f\u4e3a 0 \u7684\u65b9\u6cd5\u5305\u62ec\uff1a\u4f7f\u7528 coalesce \u51fd\u6570\u5c06\u7a7a\u503c\u6392\u5e8f\u4e3a 0\u3001\u4f7f\u7528 nullif \u51fd\u6570\u5c06\u7b49\u4e8e 0 \u7684\u503c\u6392\u5e8f\u4e3a null \u518d\u6392\u5e8f\u4e3a 0\u3001\u4f7f\u7528 case \u8bed\u53e5\u6839\u636e\u6761\u4ef6\u6392\u5e8f\u3001\u4f7f\u7528 order by \u5b50\u53e5\u6309\u964d\u5e8f\u6392\u5e8f\u7b49\u4e8e 0 \u7684\u503c\u3002\n<\/p><\/blockquote>\n

\"sql\u8bed\u53e5\u6392\u5e8f\u600e\u4e48\u6392\u52300\u63d2\u56fe\"<\/p>\n

\u5982\u4f55\u4f7f\u7528 SQL \u8bed\u53e5\u5c06\u503c\u6392\u5e8f\u4e3a 0<\/strong><\/p>\n

\u5728 SQL \u4e2d\uff0c\u5c06\u503c\u6392\u5e8f\u4e3a 0 \u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u65b9\u6cd5\u5b9e\u73b0\uff1a<\/p>\n

\u4f7f\u7528 COALESCE \u51fd\u6570<\/strong><\/p>\n

COALESCE \u51fd\u6570\u53ef\u5c06\u7b2c\u4e00\u4e2a\u975e\u7a7a\u503c\u8fd4\u56de\u3002\u901a\u8fc7\u5c06\u76ee\u6807\u5217\u4e0e 0 \u8054\u5408\u4f7f\u7528\uff0c\u53ef\u4ee5\u5c06\u7a7a\u503c\u6392\u5e8f\u4e3a 0\u3002<\/p>\n

SELECT COALESCE(column_name, 0) AS sorted_column\nORDER BY sorted_column;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u4f7f\u7528 NULLIF \u51fd\u6570<\/strong><\/p>\n
NULLIF \u51fd\u6570\u53ef\u5c06\u4e24\u4e2a\u503c\u76f8\u6bd4\u8f83\uff0c\u5e76\u5728\u76f8\u7b49\u65f6\u8fd4\u56de NULL\u3002\u901a\u8fc7\u5c06\u76ee\u6807\u5217\u4e0e 0 \u6bd4\u8f83\uff0c\u53ef\u4ee5\u5c06\u7b49\u4e8e 0 \u7684\u503c\u6392\u5e8f\u4e3a NULL\uff0c\u518d\u4f7f\u7528 COALESCE \u51fd\u6570\u5c06 NULL \u6392\u5e8f\u4e3a 0\u3002<\/p>\n
SELECT COALESCE(NULLIF(column_name, 0), 0) AS sorted_column\nORDER BY sorted_column;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u4f7f\u7528 CASE \u8bed\u53e5<\/strong><\/p>\n
CASE \u8bed\u53e5\u5141\u8bb8\u6839\u636e\u6761\u4ef6\u6267\u884c\u4e0d\u540c\u7684\u64cd\u4f5c\u3002\u53ef\u4ee5\u901a\u8fc7\u5c06\u76ee\u6807\u5217\u4e0e 0 \u6bd4\u8f83\uff0c\u5e76\u8fd4\u56de\u76f8\u5e94\u7684\u503c\u6765\u4f7f\u7528 CASE \u8bed\u53e5\u5bf9\u503c\u8fdb\u884c\u6392\u5e8f\u3002<\/p>\n
SELECT\n  CASE\n    WHEN column_name = 0 THEN 0\n    ELSE column_name\n  END AS sorted_column\nORDER BY sorted_column;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u4f7f\u7528 ORDER BY \u5b50\u53e5<\/strong><\/p>\n
\u4f7f\u7528 ORDER BY \u5b50\u53e5\uff0c\u53ef\u4ee5\u6307\u5b9a\u6392\u5e8f\u987a\u5e8f\u3002\u5c06\u76ee\u6807\u5217\u4e0e 0 \u8fdb\u884c\u6bd4\u8f83\uff0c\u5e76\u4f7f\u7528 DESC \u5173\u952e\u5b57\u4ee5\u964d\u5e8f\u6392\u5e8f\uff0c\u53ef\u4ee5\u5c06\u503c\u6392\u5e8f\u4e3a 0\u3002<\/p>\n
SELECT column_name\nORDER BY CASE\n  WHEN column_name = 0 THEN 0\n  ELSE 1\nEND DESC;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u6392\u5e8f\u600e\u4e48\u6392\u52300\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":"
sql \u4e2d\u5c06\u503c\u6392\u5e8f\u4e3a 0 \u7684\u65b9\u6cd5\u5305\u62ec\uff1a\u4f7f\u7528 coalesce \u51fd\u6570\u5c06\u7a7a\u503c\u6392\u5e8f\u4e3a 0\u3001\u4f7f\u7528 nullif \u51fd\u6570\u5c06\u7b49\u4e8e 0 \u7684\u503c\u6392\u5e8f\u4e3a null \u518d\u6392\u5e8f\u4e3a 0\u3001\u4f7f\u7528 case \u8bed\u53e5\u6839\u636e\u6761\u4ef6\u6392\u5e8f\u3001\u4f7f\u7528 order by \u5b50\u53e5\u6309\u964d\u5e8f\u6392\u5e8f\u7b49\u4e8e 0 \u7684\u503c\u3002 \u5982\u4f55\u4f7f\u7528 SQL \u8bed\u53e5\u5c06\u503c\u6392\u5e8f\u4e3a 0 \u5728 SQL \u4e2d\uff0c\u5c06\u503c\u6392\u5e8f\u4e3a 0 \u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u65b9\u6cd5\u5b9e\u73b0\uff1a \u4f7f\u7528 COALESCE \u51fd\u6570 COALESCE \u51fd\u6570\u53ef\u5c06\u7b2c\u4e00\u4e2a\u975e\u7a7a\u503c\u8fd4\u56de\u3002\u901a\u8fc7\u5c06\u76ee\u6807\u5217\u4e0e 0 \u8054\u5408\u4f7f\u7528\uff0c\u53ef\u4ee5\u5c06\u7a7a\u503c\u6392\u5e8f\u4e3a 0\u3002 SELECT COALESCE(column_name, 0) AS sorted_column ORDER BY sorted_column; \u767b\u5f55\u540e\u590d\u5236 \u4f7f\u7528 NULLIF \u51fd\u6570 NULLIF \u51fd\u6570\u53ef\u5c06\u4e24\u4e2a\u503c\u76f8\u6bd4\u8f83\uff0c\u5e76\u5728\u76f8\u7b49\u65f6\u8fd4\u56de NULL\u3002\u901a\u8fc7\u5c06\u76ee\u6807\u5217\u4e0e 0 \u6bd4\u8f83\uff0c\u53ef\u4ee5\u5c06\u7b49\u4e8e […]<\/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-5702","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5702","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=5702"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5702\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5702"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5702"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}