{"id":5967,"date":"2024-11-14T12:43:43","date_gmt":"2024-11-14T04:43:43","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5967\/"},"modified":"2024-11-14T12:43:43","modified_gmt":"2024-11-14T04:43:43","slug":"sql%e5%8e%bb%e9%87%8ddistinct%e6%80%8e%e4%b9%88%e7%94%a8","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5967\/","title":{"rendered":"sql\u53bb\u91cddistinct\u600e\u4e48\u7528"},"content":{"rendered":"

\n sql \u4e2d\u4f7f\u7528 distinct \u53bb\u91cd\u6709\u4e24\u79cd\u65b9\u6cd5\uff1aselect distinct\uff1a\u4ec5\u4fdd\u7559\u6307\u5b9a\u5217\u7684\u552f\u4e00\u503c\uff0c\u4fdd\u6301\u539f\u59cb\u8868\u987a\u5e8f\u3002group by\uff1a\u4fdd\u7559\u5206\u7ec4\u952e\u7684\u552f\u4e00\u503c\uff0c\u91cd\u65b0\u6392\u5e8f\u8868\u4e2d\u884c\u3002\n<\/p><\/blockquote>\n

\"sql\u53bb\u91cddistinct\u600e\u4e48\u7528\u63d2\u56fe\"<\/p>\n

SQL \u4e2d\u4f7f\u7528 DISTINCT \u53bb\u91cd\u7684\u4e24\u79cd\u65b9\u6cd5<\/h2>\n

\u5728 SQL \u4e2d\uff0cDISTINCT \u8fd0\u7b97\u7b26\u7528\u4e8e\u4ece\u7ed3\u679c\u96c6\u4e2d\u5220\u9664\u91cd\u590d\u7684\u884c\uff0c\u4ec5\u4fdd\u7559\u552f\u4e00\u503c\u3002\u6709\u4e24\u79cd\u65b9\u6cd5\u53ef\u4ee5\u4f7f\u7528 DISTINCT \u53bb\u91cd\uff1a<\/p>\n

\u65b9\u6cd5 1\uff1a\u4f7f\u7528 SELECT DISTINCT<\/h3>\n

\u6b64\u65b9\u6cd5\u901a\u8fc7\u5728 SELECT \u8bed\u53e5\u4e2d\u4f7f\u7528 DISTINCT \u6765\u5b9e\u73b0\u53bb\u91cd\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n

SELECT DISTINCT \u5217\u540d1, \u5217\u540d2, ... FROM \u8868\u540d;<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u4f8b\u5982\uff1a<\/p>\n
SELECT DISTINCT \u59d3\u540d, \u5e74\u9f84 FROM \u5b66\u751f;<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u6b64\u67e5\u8be2\u5c06\u8fd4\u56de\u4e00\u5f20\u542b\u6709\u552f\u4e00\u59d3\u540d\u548c\u5e74\u9f84\u7ec4\u5408\u7684\u65b0\u8868\u3002<\/p>\n
\u65b9\u6cd5 2\uff1a\u4f7f\u7528 GROUP BY<\/h3>\n
\u6b64\u65b9\u6cd5\u901a\u8fc7\u4f7f\u7528 GROUP BY \u5b50\u53e5\u6765\u5b9e\u73b0\u53bb\u91cd\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n
SELECT \u5217\u540d1, \u5217\u540d2, ...\nFROM \u8868\u540d\nGROUP BY \u5217\u540d1, \u5217\u540d2, ...;<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u4f8b\u5982\uff1a<\/p>\n
SELECT \u59d3\u540d, MIN(\u5e74\u9f84) AS \u6700\u5c0f\u5e74\u9f84\nFROM \u5b66\u751f\nGROUP BY \u59d3\u540d;<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u6b64\u67e5\u8be2\u5c06\u8fd4\u56de\u4e00\u5f20\u6839\u636e\u59d3\u540d\u5206\u7ec4\u4e14\u5177\u6709\u6700\u5c0f\u5e74\u9f84\u7684\u65b0\u8868\u3002\u7531\u4e8e\u59d3\u540d\u662f\u5206\u7ec4\u952e\uff0c\u56e0\u6b64\u65b0\u8868\u4e2d\u53ea\u6709\u552f\u4e00\u7684\u59d3\u540d\u3002<\/p>\n
\u4e24\u8005\u4e4b\u95f4\u7684\u533a\u522b<\/h3>\n
DISTINCT \u548c GROUP BY \u7684\u4e3b\u8981\u533a\u522b\u5728\u4e8e\uff1a<\/p>\n
    \n
  •  DISTINCT<\/strong> \u4fdd\u7559\u6307\u5b9a\u5217\u7684\u6240\u6709\u552f\u4e00\u503c\uff0c\u800c GROUP BY<\/strong> \u4ec5\u4fdd\u7559\u5206\u7ec4\u952e\u7684\u552f\u4e00\u503c\u3002<\/li>\n
  •  DISTINCT<\/strong> \u4fdd\u7559\u539f\u59cb\u8868\u7684\u987a\u5e8f\uff0c\u800c GROUP BY<\/strong> \u91cd\u65b0\u6392\u5e8f\u8868\u4e2d\u7684\u884c\u3002<\/li>\n<\/ul>\n
    \u5728\u9009\u62e9\u4f7f\u7528 DISTINCT \u8fd8\u662f GROUP BY \u65f6\uff0c\u9700\u8981\u6839\u636e\u6240\u8981\u8fbe\u5230\u7684\u7279\u5b9a\u7ed3\u679c\u6765\u51b3\u5b9a\u3002<\/p>\n
    \u4ee5\u4e0a\u5c31\u662fsql\u53bb\u91cddistinct\u600e\u4e48\u7528\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\u4f7f\u7528 distinct \u53bb\u91cd\u6709\u4e24\u79cd\u65b9\u6cd5\uff1aselect distinct\uff1a\u4ec5\u4fdd\u7559\u6307\u5b9a\u5217\u7684\u552f\u4e00\u503c\uff0c\u4fdd\u6301\u539f\u59cb\u8868\u987a\u5e8f\u3002group by\uff1a\u4fdd\u7559\u5206\u7ec4\u952e\u7684\u552f\u4e00\u503c\uff0c\u91cd\u65b0\u6392\u5e8f\u8868\u4e2d\u884c\u3002 SQL \u4e2d\u4f7f\u7528 DISTINCT \u53bb\u91cd\u7684\u4e24\u79cd\u65b9\u6cd5 \u5728 SQL \u4e2d\uff0cDISTINCT \u8fd0\u7b97\u7b26\u7528\u4e8e\u4ece\u7ed3\u679c\u96c6\u4e2d\u5220\u9664\u91cd\u590d\u7684\u884c\uff0c\u4ec5\u4fdd\u7559\u552f\u4e00\u503c\u3002\u6709\u4e24\u79cd\u65b9\u6cd5\u53ef\u4ee5\u4f7f\u7528 DISTINCT \u53bb\u91cd\uff1a \u65b9\u6cd5 1\uff1a\u4f7f\u7528 SELECT DISTINCT \u6b64\u65b9\u6cd5\u901a\u8fc7\u5728 SELECT \u8bed\u53e5\u4e2d\u4f7f\u7528 DISTINCT \u6765\u5b9e\u73b0\u53bb\u91cd\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a SELECT DISTINCT \u5217\u540d1, \u5217\u540d2, … FROM \u8868\u540d; \u767b\u5f55\u540e\u590d\u5236 \u4f8b\u5982\uff1a SELECT DISTINCT \u59d3\u540d, \u5e74\u9f84 FROM \u5b66\u751f; \u767b\u5f55\u540e\u590d\u5236 \u6b64\u67e5\u8be2\u5c06\u8fd4\u56de\u4e00\u5f20\u542b\u6709\u552f\u4e00\u59d3\u540d\u548c\u5e74\u9f84\u7ec4\u5408\u7684\u65b0\u8868\u3002 \u65b9\u6cd5 2\uff1a\u4f7f\u7528 GROUP BY \u6b64\u65b9\u6cd5\u901a\u8fc7\u4f7f\u7528 GROUP BY \u5b50\u53e5\u6765\u5b9e\u73b0\u53bb\u91cd\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a SELECT \u5217\u540d1, \u5217\u540d2, … FROM […]<\/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-5967","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5967","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=5967"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5967\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5967"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}