{"id":317047,"date":"2021-02-04T08:19:03","date_gmt":"2021-02-04T00:19:03","guid":{"rendered":"http:\/\/4563.org\/?p=317047"},"modified":"2021-02-04T08:19:03","modified_gmt":"2021-02-04T00:19:03","slug":"%e6%b1%82%e5%8a%a9%e4%b8%80%e4%b8%aa-sql-%e5%86%99%e6%b3%95-%e4%b8%80%e4%b8%aa%e8%a1%a8-%e5%8f%aa%e6%9c%89-2-%e4%b8%aa%e5%ad%97%e6%ae%b5","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=317047","title":{"rendered":"\u6c42\u52a9\u4e00\u4e2a sql \u5199\u6cd5, \u4e00\u4e2a\u8868, \u53ea\u6709 2 \u4e2a\u5b57\u6bb5"},"content":{"rendered":"
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\u6c42\u52a9\u4e00\u4e2a sql \u5199\u6cd5, \u4e00\u4e2a\u8868, \u53ea\u6709 2 \u4e2a\u5b57\u6bb5 <\/h1>\n

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\u8cc7\u6df1\u5927\u4f6c : DinoStray <\/span> <\/i> 9<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

\u6709\u4e2a\u8868, \u53ea\u6709\u4e24\u4e2a\u5b57\u6bb5 a, b, \u53d6\u503c\u8303\u56f4\u90fd\u662f 1- 3
\u73b0\u5728\u6211\u60f3\u7edf\u8ba1, \u904d\u5386 a \u7684\u6bcf\u4e2a\u503c, \u5bf9\u5e94\u7684 b \u6bcf\u4e2a\u503c\u51fa\u73b0\u6b21\u6570 <\/p>\n

\u5217    a=1              a=2              a=3 b=1  b=1 \u51fa\u73b0 3 \u6b21  b=1 \u51fa\u73b0 2 \u6b21  b=1 \u51fa\u73b0 2 \u6b21     b=2  b=2 \u51fa\u73b0 0 \u6b21  b=2 \u51fa\u73b0 1 \u6b21  b=2 \u51fa\u73b0 2 \u6b21 b=3  b=3 \u51fa\u73b0 1 \u6b21  b=3 \u51fa\u73b0 1 \u6b21  b=3 \u51fa\u73b0 8 \u6b21 <\/code><\/pre>\n<\/p><\/div>\n
 \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (12<\/span>)        <\/div>\n
 <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
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     \u8cc7\u6df1\u5927\u4f6c : ynwcel <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 “`sql
    select 
     b,
     (select count(*) from <table> where a = 1 and b = outa.b) as a1,
     (select count(*) from <table> where a = 2 and b = outa.b) as a2,
     (select count(*) from <table> where a = 3 and b = outa.b) as a3
    from (select distinct b from <table>) as outa
    “`
    \u4e0d\u77e5\u9053\u6ee1\u8db3\u8981\u6c42\u4e0d\u3002~\uff1f                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : DinoStray <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @ynwcel \u8c22\u8c22\u54c8, \u4e0d\u6ee1\u8db3, \u56e0\u4e3a\u95ee\u9898\u88ab\u6211\u6781\u5ea6\u7b80\u5316\u4e86, \u5b9e\u9645\u53d6\u503c\u8303\u56f4\u5176\u5b9e\u662f\u5f88\u5927\u7684                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : DinoStray <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @ynwcel \u6240\u4ee5\u5e0c\u671b\u4e0d\u80fd a=1 2 3 \u8fd9\u79cd\u5199\u6b7b\u7684, \u6700\u597d\u80fd\u53d8\u91cf\u53e6\u4e00\u4e2a\u7ed3\u679c\u96c6                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : liprais <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4f60\u8981\u7684\u4e0d\u5c31\u662f a,b,count(*)\u4e48?                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : ttys001 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 select a, count(distinct b) from table group by a;                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : ttys001 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @ttys001 select a, b, count(distinct b) from table group by a;                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : asAnotherJack <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 select a,b,count(*) from t group by a,b;
    \u8fd9\u6837\u6709\u4ec0\u4e48\u95ee\u9898\u5417                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : xuanbg <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 7 \u5e94\u8be5\u662f\u5bf9\u7684                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : Still4 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4e00\u822c sql \u505a\u52a8\u6001\u4e8c\u7ef4\u8868\u6709\u70b9\u96be\u5427\uff0c\u8003\u8651\u5b58\u50a8\u8fc7\u7a0b\uff0c\u6216\u8005\u8bfb\u51fa\u6765\u5916\u90e8\u7a0b\u5e8f\u5355\u72ec\u5904\u7406                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : zlowly <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u5e94\u8be5\u5c31\u662f 7 \u7684\u7edf\u8ba1\u65b9\u5f0f\u5c31\u884c\u4e86\uff0c\u9664\u975e\u4e3b\u5e0c\u671b\u7684\u6570\u636e\u5c55\u73b0\u65b9\u5f0f\u4e0d\u540c\uff0c\u96be\u9053\u662f\u6a2a\u8f74\u4e3a a \u7684\u53d6\u503c\u96c6\u5408\uff0c\u7ad6\u8f74\u4e3a b \u7684\u53d6\u503c\u96c6\u5408\u8fd9\u79cd\u4e0d\u5b9a\u5bbd\u8868\u683c\uff1f                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
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     \u8cc7\u6df1\u5927\u4f6c : cslive <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 7 \u662f\u53ef\u4ee5\u5f97\uff0c\u5982\u679c\u6a2a\u6392\u5c11\u53ef\u4ee5\u518d\u7528 case when \u8f6c\u4e00\u4e0b\uff0c\u524d\u6bb5\u65f6\u95f4\u6211\u8fd9\u6837\u7ad6\u8f6c\u6a2a\u641e\u4e86\u51e0\u5f20\u8868\uff0c\u8f6c\u4e86\u51e0\u5341\u5217                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : DinoStray <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @asAnotherJack \u6ca1\u95ee\u9898, \u5c31\u8981\u8fd9\u4e2a, \u6211\u5bf9 sql \u4e0d\u719f\u6089\u6ca1\u60f3\u5230, \u8c22\u8c22                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"
    \u6c42\u52a9\u4e00\u4e2a sql \u5199\u6cd5, \u4e00\u4e2a\u8868,…<\/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\/317047"}],"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=317047"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/317047\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=317047"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=317047"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=317047"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}