Question

我试图根据分配的文件计算多个用户，并按这些文件进行分组＆＃39;具有以下MySQL查询的状态：

 <html xmlns="http://www.w3.org/1999/xhtml" ng-app="myApp">
<head runat="server">
    <title></title>
    <script src="js/jquery-2.1.3.min.js"></script>        
    <link href="css/bootstrap.css" rel="stylesheet" />
    <link href="https://cdn.rawgit.com/angular-ui/bower-ui-grid/master/ui-grid.min.css" rel="stylesheet" />
    <script src="js/bootstrap.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular.min.js"></script>
    <script src="https://cdn.rawgit.com/angular-ui/bower-ui-grid/master/ui-grid.min.js"></script>
    <script>
        var app = angular.module('myApp', []);
        app.controller('MyCtrl1', function ($scope) {
            $scope.today = new Date();
        });
        app.controller('MyCtrl2', function ($scope) {
            $scope.myData = [{ name: "Moroni", age: 50 },
                             { name: "Tiancum", age: 43 },
                             { name: "Jacob", age: 27 },
                             { name: "Nephi", age: 29 },
                             { name: "Enos", age: 34 }];
            $scope.gridOptions = { data: 'myData' };
        });
    </script>
</head> 
<body>
    <form id="form1" runat="server">
        <div ng-controller="MyCtrl1">
            <div class="jumbotron">
            </div>
            <div class="container container-fluid">
                <div class="row">
                    <div class="col-lg-offset-2 col-lg-4">
                        <div class="table table-hover" ng-grid="gridOptions"></div>
                    </div>
                </div>
                <p class="text-right">{{ today | date }}</p>
            </div>
        </div>
        <div ng-controller="MyCtrl2">
            <div class="table table-hover" ng-grid="gridOptions"></div>
        </div>
    </form>
</body>
</html>

我的问题是，如果没有用户拥有某个状态的文件，查询将不会返回该行：

目前查询返回的值如下：

SELECT
  (CASE WHEN F.status IS null THEN 'records' 
   WHEN F.status = 0 THEN 'prospects' 
   WHEN F.status >= 1 AND F.status < 4 THEN 'open'
   WHEN F.status = 4 THEN 'archived' END) AS FileStatus,
  count(DISTINCT U.id) as users
FROM
  users_table U
  LEFT OUTER JOIN files_table as F on (F.user_id = U.id or F.user_id IS NULL)
WHERE U.team = 1  
GROUP BY FileStatus DESC

但是我想要显示零或空值，如下所示：

+------------+-------+
| FileStatus | users |
+------------+-------+
| prospects  |   5   |
| open       |   10  |
| archived   |   12  |
+------------+-------+

我确定这非常简单，但任何帮助都会非常受欢迎✌️

Answer 1

要获取所有文件状态，您需要有一个包含这些状态的表。如果不可用，您可以使用子查询内联生成它。

其次，用户团队的条件应该是连接条件的一部分，否则（当你将它放在where子句中时）它会将外连接转换为内连接。

关于“记录”计数的评论之后，无论如何使用外部联接都没有任何意义。我建议为该类别建议union：

SELECT     FileStatus,
           count(DISTINCT U.id) as users
FROM       (SELECT 0 as status, 'prospects' as FileStatus
            UNION ALL SELECT 1, 'open'
            UNION ALL SELECT 2, 'open'
            UNION ALL SELECT 3, 'open'
            UNION ALL SELECT 4, 'archived') as C
INNER JOIN files_table as F 
        on F.status = C.status
INNER JOIN users_table U
        on F.user_id = U.id
       and U.team = 1  
GROUP BY   FileStatus DESC
UNION ALL
SELECT    'records',
          count(*)
FROM      users_table
WHERE     id NOT IN (SELECT user_id FROM files_table)
AND       team = 1

如果要使用范围，则在子查询中返回低/高端，并相应地调整连接条件：

SELECT     FileStatus,
           count(DISTINCT U.id) as users
FROM       (SELECT 0 as statusFrom, 0 statusTo, 'prospects' as FileStatus
            UNION ALL SELECT 1, 3, 'open'
            UNION ALL SELECT 4, 4, 'archived') as C
INNER JOIN files_table as F 
        on F.status between C.statusFrom and C.statusTo
INNER JOIN users_table U
        on F.user_id = U.id
       and U.team = 1  
GROUP BY   FileStatus DESC
UNION ALL
SELECT    'records',
          count(*)
FROM      users_table
WHERE     id NOT IN (SELECT user_id FROM files_table)
AND       team = 1

选择CASI WHI ALIAS且COUNT不返回ZERO值

1 个答案: