{"id":186659,"date":"2020-10-18T21:19:14","date_gmt":"2020-10-18T13:19:14","guid":{"rendered":"http:\/\/4563.org\/?p=186659"},"modified":"2020-10-18T21:19:14","modified_gmt":"2020-10-18T13:19:14","slug":"%e8%af%9d%e8%af%b4%e8%bf%99%e4%b8%a4%e4%b8%aa-sql-%e4%b8%ba%e5%95%a5%e5%92%8c%e6%88%91%e9%a2%84%e6%83%b3%e7%9a%84%e4%b8%8d%e5%a4%aa%e4%b8%80%e6%a0%b7","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=186659","title":{"rendered":"\u8bdd\u8bf4\u8fd9\u4e24\u4e2a sql \u4e3a\u5565\u548c\u6211\u9884\u60f3\u7684\u4e0d\u592a\u4e00\u6837"},"content":{"rendered":"
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\u8bdd\u8bf4\u8fd9\u4e24\u4e2a sql \u4e3a\u5565\u548c\u6211\u9884\u60f3\u7684\u4e0d\u592a\u4e00\u6837 <\/h1>\n

<\/p>\n

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\u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span> <\/i> 5<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n
select * from t1  where  not exists (select 1 from t2 where t1.name = t2.name)  select * from t1  where exists (select 1 from t2 where t1.name != t2.name) <\/code><\/pre>\n
\u6211\u672c\u610f\u662f\u627e t1 \u6bd4 t2 \u591a\u7684\u6570\u636e\uff0c\u7ed3\u679c\u628a t1 \u7684\u6240\u6709\u4e1c\u897f\u90fd\u8fd4\u56de\u4e86<\/p>\n<\/p><\/div>\n
 \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (24<\/span>)        <\/div>\n
 <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : BrettD <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4e3a\u5565\u8981\u8fd9\u6837\u5199                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @BrettD \u56e0\u4e3a\u4e0d\u5b58\u5728\u561b\u3002\u3002\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u8bdd\u8bf4\u6362\u6210 in\uff0c\u6bd4\u8f83\u5bb9\u6613\u770b\u51fa\u6765\u4e00\u4e0b\u5427\uff0c\u5e94\u8be5\u662f\u7b49\u4ef7\u4e8e
    “`
    select * from t1 where not in(select name from t2)
    \u7b2c\u4e8c\u4e2a\u597d\u50cf\u4e0d\u592a\u5bf9
    “`                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : wisunny <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u7ffb\u8bd1\u6210\u6c49\u8bed\u5c31\u597d\u7406\u89e3\u591a\u4e86\uff0c\u4e00\u4e2a\u662f\u4e0d\u5b58\u5728\u76f8\u7b49\u7684\uff0c\u4e00\u4e2a\u662f\u5b58\u5728\u4e0d\u7b49\u7684\u3002\u800c\u5b58\u5728\u4e0d\u7b49\u7684\u53ea\u8981\u5b58\u5728\u4e00\u4e2a\u5c31\u59cb\u7ec8\u4e3a true\uff0c\u7ed3\u679c\u81ea\u7136\u4e0d\u4e00\u6837                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : chendy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 select 1 from t2 where t1.name != t2.name \u8fd9\u4e2a\u2026\u53ea\u8981\u6709\u4e0d\u540c\u7684\u5c31\u6709\u8fd4\u56de\uff0c\u4e8e\u662f\u5c31\u8fd4\u56de\u5168\u90e8\u5457                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @wisunny \u90a3\u8fd9\u4e2a\u600e\u4e48\u904d\u5386\u7684\u554a\uff0c\u611f\u89c9\u602a\u602a\u7684                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @chendy \u6240\u4ee5\u8bf4\u7b2c\u4e8c\u4e2a sql \u5c31\u76f8\u5f53\u4e8e\u76f4\u63a5 select * from t1 ?                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : chendy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @luxinfl \u4e5f\u4e0d\u662f\u4f46\u662f\u5dee\u4e0d\u591a\uff0c\u53ea\u8981 t2 \u6709\u6570\u636e\uff0c\u800c\u4e14\u4e0d\u5168\u90fd\u548c t1 \u7684 name \u4e00\u6837\u5c31\u6709\u8fd4\u56de                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : kiracyan <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 select * from t1 where name not in (select name from t2)                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : no1xsyzy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @luxinfl \u9664\u975e t2 \u91cc\u53ea\u6709\u4e00\u6761
    \u628a SQL \u91cd\u65b0\u5199\u4e3a\u96c6\u5408\u63a8\u5bfc\u5f0f\uff1a<\/p>\n
    \u5f0f 1 \u7b49\u4ef7\u4e8e
    { x | x in t1, neg exists_{y in t2} (x.name = y.name) }
    = { x | x in t1, forall_{y in t2} (x.name neq y.name) }<\/p>\n
    \u5f0f 2 \u7b49\u4ef7\u4e8e
    { x | x in t1, exists_{y in t2} (x.name neq y.name) }<\/p>\n
    \u4f60\u89c9\u5f97\u4e00\u6837\u5417\uff1f                                                            <\/p><\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @chendy \u4f46\u662f\u6211 t1 \u548c t2 \u7684\u8868\u6570\u636e\u4e00\u6837\uff0c\u7b2c\u4e8c\u4e2a sql \u8fd8\u662f\u6709\u8fd4\u56de\u554a                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : YYYYMMDDHHSS <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u7ffb\u8bd1\uff1a1\uff0c\u5bf9\u4e8e T1 \u7684\u67d0\u4e00\u884c\uff0c\u53ea\u8981\u5b58\u5728\u4e00\u884c T2.NAME == T1.NAME\uff0c\u5c31\u8fd4\u56de T1.*\uff1b
     2\uff0c\u5bf9\u4e8e T1 \u7684\u67d0\u4e00\u884c\uff0c\u53ea\u8981\u5b58\u5728\u4e00\u884c T2.NAME <> T1.NAME.\u5c31\u8fd4\u56de T1.*; \u90a3\u4e48\u54ea\u6015\u771f\u7684\u53ea\u6709\u4e00\u4e2a name \u4e0d\u5728 T1 \u4e2d\uff0c\u5bf9\u4e8e\u4efb\u4f55\u4e00\u4e2a T1 \u884c\u90fd\u6ee1\u8db3….                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : no1xsyzy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u8bdd\u8bf4
    select * from t1 where name not in (select name from t2)
    \u548c
    select t1.* from t1 left join t2 on t1.name = t2.name where t2.name = null
    \u4e24\u4e2a\u76f8\u6bd4\u6548\u7387\u5982\u4f55\uff1f<\/p>\n
    \u4f46\u7b2c\u4e8c\u4e2a\u53ef\u8bfb\u6027\u592a\u5dee\u4e86\uff0c\u53c8\u8981 t1.name = t2.name \u53c8\u8981 t2.name = null\u2026\u2026 \u8fd8\u662f\u6211\u7684\uff08\u5947\u6280\u6deb\u5de7\uff09\u5199\u6cd5\u6709\u95ee\u9898\uff1f
    \u5982\u679c\u6548\u7387\u53ea\u7a0d\u9ad8\u4e00\u70b9\u8fd8\u662f\u4e0d\u8981\u7528 2\uff0c\u5982\u679c\u6548\u7387\u63d0\u5347\u975e\u5e38\u9ad8\u90a3\u5c31\u52a0\u6ce8\u91ca                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : no1xsyzy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @luxinfl \u6ce8\u610f \u201c\u4e0d\u5168\u90fd\u548c\u201d
    \u8fd9\u4e2a name \u88ab\u8ba4\u4e3a TLD \u592a\u50bb\u4e86\u2026\u2026
    \u987a\u4fbf\u8bd5\u8bd5\uff1a
    `t1`.name [t1].name                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : wolfie <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 t2 \u5982\u679c\u662f\u7a7a\u8868\uff0cexists \u76f4\u63a5\u8fd4\u56de false \u3002
    \u7b2c\u4e8c\u6761 sql \u8ddf\u4f60\u9700\u6c42\u4e0d\u4e00\u6837\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @no1xsyzy \u7b2c\u4e00\u4e2a\u662f\u4e0d\u662f\u76f8\u5f53\u4e8e
    for x in t1:
     for y in t2:
     if(x.name == y.name):
     result.add(x)
     break;                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @luxinfl \u4e0d\u5bf9\uff0c\u6761\u4ef6\u5199\u9519\u4e86\u3002\u3002\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : no1xsyzy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @luxinfl \u554a\uff0c\u7528 Python \u89e3\u91ca\u7684\u8bdd\u8fd9\u4e48\u5199\u5427\uff1a
    \u5f0f 1\uff1a
    [x for x in t1 if not any(x[‘name’] == y[‘name’] for y in t2)]
    \u6839\u636e\u53cd\u6f14\u5f8b\u5c55\u5f00\uff0c\u5176\u7b49\u4ef7\u4e8e
    [x for x in t1 if all(x[‘name’] != y[‘name’] for y in t2)]<\/p>\n
    \u5f0f 2\uff1a
    [x for x in t1 if any(x[‘name’] != y[‘name’] for y in t2)]<\/p>\n
    \u4e00\u4e2a\u662f all \u4e00\u4e2a\u662f any                                                            <\/p><\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @no1xsyzy \u8c22\u8c22\u5927\u4f6c\uff0c\u8fd9\u4e48\u770b\u6211\u5c31\u61c2\u4e86\u3002\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : samv2 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u627e t1 \u6bd4 t2 \u591a\u7684\uff0c\u53ef\u4ee5\u8fd9\u6837\u5199
    select t1.* from t1
    left join t2
     on t1.name=t2.name
    where t2.name is null                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : c6h6benzene <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @no1xsyzy #13 \u7b2c\u4e8c\u4e2a\u5c31\u662f\u6807\u51c6\u7684 sql \u554a\uff0c\u4e00\u5929\u5230\u665a\u90fd\u5199\u8fd9\u79cd\uff0cname=name \u662f\u8fde\u63a5\u6761\u4ef6\uff0cwhere \u662f\u9650\u5236\u6761\u4ef6\uff0c\u4e0d\u4f1a\u8bfb\u6df7\u7684\u3002\u53e6\u5916\u8981\u7528 is null                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : xdsty <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u76f4\u63a5\u5de6\u8fde\u63a5\u627e\u60ac\u7a7a\u7684\u8bb0\u5f55\u5c31\u53ef\u4ee5\u4e86                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : luxinfl <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @samv2 \u8fd9\u4e2a\u662f\u53ef\u4ee5\uff0c\u6211\u53ea\u662f\u6ca1\u641e\u592a\u61c2 exists \u548c not exists \u600e\u4e48\u73a9\u7684                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
     \u8cc7\u6df1\u5927\u4f6c : xiyangzuile <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u7b2c\u4e8c\u6761\u662f\u56e0\u4e3a \u5185\u90e8\u67e5\u8be2\u5224\u65ad t1.name !=t2.name \u4f1a\u5bfc\u81f4\u6c38\u8fdc\u90fd\u8fd4\u56de true , \u6240\u4ee5\u8fd4\u56de\u7ed3\u679c\u662f t1 \u7684\u6240\u6709\u7ed3\u679c                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"
    \u8bdd\u8bf4\u8fd9\u4e24\u4e2a sql \u4e3a\u5565\u548c\u6211\u9884\u60f3\u7684…<\/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\/186659"}],"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=186659"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/186659\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=186659"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=186659"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=186659"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}