{"id":200265,"date":"2025-05-06T10:56:36","date_gmt":"2025-05-06T02:56:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200265\/"},"modified":"2025-05-06T10:56:36","modified_gmt":"2025-05-06T02:56:36","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%af%a2%e5%b0%86%e6%9f%a5%e8%af%a2%e7%bb%93%e6%9e%9c%e5%88%86%e7%bb%84%e5%b9%b6%e8%a1%8c%e5%b1%95%e7%a4%ba%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200265\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528\u5b50\u67e5\u8be2\u5c06\u67e5\u8be2\u7ed3\u679c\u5206\u7ec4\u5e76\u884c\u5c55\u793a\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

\u5982\u4f55\u4f7f\u7528\u5b50\u67e5\u8be2\u5c06\u67e5\u8be2\u7ed3\u679c\u5206\u7ec4\u5e76\u884c\u5c55\u793a\uff1f<\/h1>\n

\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u52aa\u529b\u5b66\u4e60\u5427\uff01\u672c\u6587\u4e3b\u8981\u8bb2\u89e3\u4e86\u7b49\u7b49\u76f8\u5173\u77e5\u8bc6\u70b9\uff0c\u6211\u4f1a\u5728\u4e3b\u673a\u5b9d\u8d1d\u4e2d\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u7684\u7cfb\u5217\u6587\u7ae0\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u5e76\u79ef\u6781\u7559\u8a00\u5efa\u8bae\u3002\u4e0b\u9762\u5c31\u5148\u4e00\u8d77\u6765\u770b\u4e00\u4e0b\u672c\u7bc7\u6b63\u6587\u5185\u5bb9\u5427\uff0c\u5e0c\u671b\u80fd\u5e2e\u5230\u4f60\uff01<\/p>\n

<\/p>\n

\u5de7\u7528\u5b50\u67e5\u8be2\u5b9e\u73b0\u5206\u7ec4\u5e76\u884c\u5c55\u793a<\/strong><\/p>\n

\u60f3\u8981\u5b9e\u73b0\u5c06\u67e5\u8be2\u7ed3\u679c\u5206\u7ec4\u5e76\u884c\u5c55\u793a\uff0c\u53ef\u4ee5\u4f7f\u7528\u5b50\u67e5\u8be2\u3002\u5177\u4f53\u800c\u8a00\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u6b65\u9aa4\u5b9e\u73b0\uff1a<\/p>\n

    \n
  1. \u6309\u5e74\u6708\u5206\u7ec4\u67e5\u8be2\u4e0a\u534a\u5e74\u7684\u6570\u636e\uff1a<\/strong>\u4f7f\u7528 sum() \u805a\u5408\u51fd\u6570\u8ba1\u7b97\u6bcf\u4e2a name \u7684\u4e0a\u534a\u5e74 num \u603b\u548c\u3002<\/li>\n
  2. \u4f7f\u7528\u5b50\u67e5\u8be2\u83b7\u53d6\u4e0b\u534a\u5e74\u7684\u6570\u636e\uff1a<\/strong>\u521b\u5efa\u4e00\u4e2a\u5b50\u67e5\u8be2\uff0c\u5bf9 name \u8fdb\u884c\u5206\u7ec4\uff0c\u5e76\u8ba1\u7b97\u6bcf\u4e2a name \u7684\u4e0b\u534a\u5e74 num \u603b\u548c\u3002<\/li>\n
  3. \u8fde\u63a5\u4e3b\u67e5\u8be2\u548c\u5b50\u67e5\u8be2\uff1a<\/strong>\u4f7f\u7528 left join \u5c06\u4e3b\u67e5\u8be2\u548c\u5b50\u67e5\u8be2\u8fde\u63a5\u8d77\u6765\u3002\u4e3b\u67e5\u8be2\u8d1f\u8d23\u4e0a\u534a\u5e74\u7684\u6570\u636e\uff0c\u800c\u5b50\u67e5\u8be2\u8d1f\u8d23\u4e0b\u534a\u5e74\u7684\u6570\u636e\u3002<\/li>\n
  4. \u586b\u5145\u4e0b\u534a\u5e74\u7684 null \u503c\uff1a<\/strong>\u7531\u4e8e\u5b50\u67e5\u8be2\u53ef\u80fd\u65e0\u6cd5\u5339\u914d\u5230\u6240\u6709 name\uff0c\u56e0\u6b64\u9700\u8981\u4f7f\u7528 ifnull() \u51fd\u6570\u5c06\u4e0b\u534a\u5e74\u7684 null \u503c\u586b\u5145\u4e3a 0\u3002<\/li>\n<\/ol>\n

    \u4fee\u6539\u540e\u7684 sql \u67e5\u8be2\u5982\u4e0b\uff1a<\/p>\n

    SELECT\n    t.name,\n    start_date,\n    SUM( t.num ) AS shang_sum,\n    IFNULL(t2.xia_sum,0)\nFROM\n    `task` t\n    LEFT JOIN ( SELECT NAME, SUM( num ) xia_sum FROM task WHERE MONTH ( start_date ) < 7 GROUP BY `name` ) t2 ON t2.NAME = t.NAME \nWHERE\n    MONTH ( start_date ) >= 7 \nGROUP BY\n    `name`<\/pre>\n
    \u6267\u884c\u6b64\u67e5\u8be2\uff0c\u5c06\u8f93\u51fa\u4ee5\u4e0b\u7ed3\u679c\uff1a<\/p>\n\n\n\n\n\n\n
    name<\/th>\nstart_date<\/th>\nshang_sum<\/th>\nxia_sum<\/th>\n<\/tr>\n<\/thead>\n
    ceshi<\/td>\n\u4e0a\u534a\u5e74<\/td>\n3<\/td>\n1<\/td>\n<\/tr>\n
    sss<\/td>\n\u4e0b\u534a\u5e74<\/td>\n0<\/td>\n2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u6587\u4e2d\u5173\u4e8e\u7684\u77e5\u8bc6\u4ecb\u7ecd\uff0c\u5e0c\u671b\u5bf9\u4f60\u7684\u5b66\u4e60\u6709\u6240\u5e2e\u52a9\uff01\u82e5\u662f\u53d7\u76ca\u532a\u6d45\uff0c\u90a3\u5c31\u52a8\u52a8\u9f20\u6807\u6536\u85cf\u8fd9\u7bc7\u300a\u5982\u4f55\u4f7f\u7528\u5b50\u67e5\u8be2\u5c06\u67e5\u8be2\u7ed3\u679c\u5206\u7ec4\u5e76\u884c\u5c55\u793a\uff1f\u300b\u6587\u7ae0\u5427\uff0c\u4e5f\u53ef\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e86\u89e3\u76f8\u5173\u6280\u672f\u6587\u7ae0\u3002<\/p>\n
    \n
    \n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
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