{"id":317043,"date":"2021-02-04T04:36:46","date_gmt":"2021-02-03T20:36:46","guid":{"rendered":"http:\/\/4563.org\/?p=317043"},"modified":"2021-02-04T04:36:46","modified_gmt":"2021-02-03T20:36:46","slug":"%e8%bf%94%e5%9b%9e%e5%ad%a6%e7%94%9f%e7%9a%84%e5%b9%b3%e5%9d%87%e5%ad%a6%e5%88%86%e7%bb%a9%e7%82%b9%ef%bc%8c-%e5%8f%af%e4%bb%a5%e4%b8%8d%e7%94%a8-row_number-%e5%92%8c-case-%e8%af%ad%e5%8f%a5-%e5%90%97","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=317043","title":{"rendered":"\u8fd4\u56de\u5b66\u751f\u7684\u5e73\u5747\u5b66\u5206\u7ee9\u70b9\uff0c \u53ef\u4ee5\u4e0d\u7528 ROW_NUMBER \u548c CASE \u8bed\u53e5 \u5417\uff1f \u76ee\u524d\u7684\u6570\u636e\u5e93 \uff08\u8bdd\u8bf4\u8fd9\u6837\u7684\u95ee\u9898 \u653e\u54ea\u4e2a\u8282\u70b9\u6700\u201d\u5408\u7406\u201c \u5462\uff1f \u5bf9\u63d0\u95ee\u8005\uff0c \u6700\u53cb\u597d\u5462\uff1f"},"content":{"rendered":"
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\u8fd4\u56de\u5b66\u751f\u7684\u5e73\u5747\u5b66\u5206\u7ee9\u70b9\uff0c \u53ef\u4ee5\u4e0d\u7528 ROW_NUMBER \u548c CASE \u8bed\u53e5 \u5417\uff1f \u76ee\u524d\u7684\u6570\u636e\u5e93 \uff08\u8bdd\u8bf4\u8fd9\u6837\u7684\u95ee\u9898 \u653e\u54ea\u4e2a\u8282\u70b9\u6700\u201d\u5408\u7406\u201c \u5462\uff1f \u5bf9\u63d0\u95ee\u8005\uff0c \u6700\u53cb\u597d\u5462\uff1f <\/h1>\n

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\u8cc7\u6df1\u5927\u4f6c : wxmomomowx <\/span> <\/i> 5<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

chengji<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
sid<\/th>\ncid<\/th>\nquarter<\/th>\nyear<\/th>\ngrade<\/th>\n<\/tr>\n<\/thead>\n
A1<\/td>\nmath101<\/td>\nWinter<\/td>\n2013<\/td>\n4<\/td>\n<\/tr>\n
A1<\/td>\nChinese102<\/td>\nSpring<\/td>\n2015<\/td>\n2<\/td>\n<\/tr>\n
A1<\/td>\nChinese103<\/td>\nSpring<\/td>\n2015<\/td>\n3<\/td>\n<\/tr>\n
A2<\/td>\nmath103<\/td>\nSpring<\/td>\n2017<\/td>\n4<\/td>\n<\/tr>\n
A2<\/td>\nmath100<\/td>\nWinter<\/td>\n2019<\/td>\n0<\/td>\n<\/tr>\n
A3<\/td>\nChinese100<\/td>\nWinter<\/td>\n2018<\/td>\n4<\/td>\n<\/tr>\n
A3<\/td>\nmath102A<\/td>\nFall<\/td>\n2020<\/td>\n4<\/td>\n<\/tr>\n
A3<\/td>\nart101<\/td>\nWinter<\/td>\n2020<\/td>\n3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
WITH t AS (     SELECT sid, year, quarter, AVG(grade) AS gpa,            ROW_NUMBER() OVER (PARTITION BY sid                               ORDER BY year DESC, CASE quarter                                                                 WHEN 'Fall' THEN 3                                                                WHEN 'Spring' THEN 2                                                                WHEN 'Winter' THEN 1 END DESC) rn     FROM chengji     GROUP BY sid, year, quarter )  SELECT sid, year, quarter, gpa FROM t WHERE rn = 1;  <\/code><\/pre>\n
\u76ee\u524d\uff0c \u8fd9\u4e2a sql \u8bed\u53e5\u8fd4\u56de\uff0c \u662f\u60f3\u8981\u7684\u7ed3\u679c\u4e86<\/p>\n\n\n\n\n\n\n\n
sid<\/th>\nyear<\/th>\nquarter<\/th>\ngpa<\/th>\n<\/tr>\n<\/thead>\n
A1<\/td>\n2015<\/td>\nSpring<\/td>\n2.5<\/td>\n<\/tr>\n
A2<\/td>\n2019<\/td>\nWinter<\/td>\n0.0<\/td>\n<\/tr>\n
A3<\/td>\n2020<\/td>\nWinter<\/td>\n3.0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u6709\u53ef \u53ef\u4ee5\u4e0d\u7528 ROW_NUMBER \u548c CASE \u8bed\u53e5 \u4f46\u662f\u540c\u6837\u8fd4\u56de \u4e00\u6837\u7684\u7ed3\u679c\u5417\uff1f sqlite \u73af\u5883<\/p>\n<\/p><\/div>\n
 \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (0<\/span>)        <\/div>\n
 <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
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    \u8fd4\u56de\u5b66\u751f\u7684\u5e73\u5747\u5b66\u5206\u7ee9\u70b9\uff0c \u53ef\u4ee5\u4e0d\u7528…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/317043"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=317043"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/317043\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=317043"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=317043"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=317043"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}