Question

下面是我的查询，它不返回任何行，这根据数据库记录是正确的。

SELECT  CustomerID ,
        'Forwarder' AS CustType ,
        RForLocation ,
        YEAR(ReceivedDate) AS CurrentYear ,
        CONVERT(VARCHAR, COUNT(CASE WHEN MONTH(ReceivedDate) = 1 THEN 1
                                    ELSE 0
                               END)) AS Jan
FROM    RootTable
WHERE   Customerid = 12742
        AND YEAR(ReceivedDate) = 2014
GROUP BY CustomerID ,
        RForLocation ,
        YEAR(ReceivedDate)

但我的要求是我应该获得一个空行，其中customerId，CustType，CurrentYear和Jan Count为零（0）

以下是我的要求

CustomerId  CustType   CurrentYear   Jan
12742       Forwarder   2014          0

由于请帮忙

Answer 1

SELECT    CustomerID 
        ,'Forwarder' AS CustType
        ,RForLocation 
        ,YEAR(ReceivedDate) AS CurrentYear
        ,ISNULL(
          NULLIF(
              COUNT(CASE WHEN MONTH(ReceivedDate) = 1 THEN 1 ELSE 0 END)
                 , 0)
              , '')
                                     AS Jan
FROM    RootTable
WHERE   Customerid = 12742
        AND YEAR(ReceivedDate) = 2014
GROUP BY CustomerID ,
        RForLocation ,
        YEAR(ReceivedDate)

Answer 2

更改CASE声明

CONVERT(VARCHAR, CASE WHEN count(MONTH(ReceivedDate) = 1) 
                           THEN count(MONTH(ReceivedDate) = 1) 

               ELSE 0
end

Answer 3

SELECT  
RootTable.CustomerID ,
'Forwarder' AS CustType ,
RForLocation ,
YEAR(ReceivedDate) AS CurrentYear,
SUB1.MON_COL,
CASE WHEN sub1.CNT IS NULL THEN 0 ELSE sub1.CNT END AS CNT    
FROM    RootTable
LEFT JOIN 
(
    SELECT COUNT(1) CNT, CustomerId,MONTH(ReceivedDate) AS MON_COL,YEAR(ReceivedDate) AS YEAR_COL
    FROM    RootTable
    GROUP BY CustomerId,MONTH(ReceivedDate),YEAR(ReceivedDate)
) sub1 ON sub1.CustomerID = RootTable.CustomerId AND MONTH(ReceivedDate) = sub1.MON_COL AND YEAR(ReceivedDate) = sub1.YEAR_COL

WHERE RootTable.CustomerId=2

Answer 4

无论我能理解什么，请找到脚本和更新的查询，我试过了。

创建表：

Create table RootTable
(CustomerID int, 
    RForLocation varchar(20), 
    ReceivedDate datetime)

插入数据：

insert into RootTable
Values(1, 'A', '1-Jan-2013'),
    (2, 'A', '1-Feb-2013'),
    (3, 'B', '1-Jan-2013'),
    (4, 'B', '1-Mar-2013')

查询以获取记录：

SELECT  CustomerID ,
        'Forwarder' AS CustType ,
        RForLocation ,
        '2014' AS CurrentYear ,
        CONVERT(VARCHAR, COUNT(CASE WHEN MONTH(ReceivedDate) = 1 AND YEAR(ReceivedDate) = 2014 THEN 1
                                    ELSE null
                               END)) AS Jan
FROM    RootTable
WHERE   Customerid = 1
GROUP BY CustomerID ,
        RForLocation;

因为即使他没有特定年份的记录，我也希望为客户提供记录，但我不需要在where子句中给出日期条件，而是我可以根据年份进行计数，这将给出我需要输出。

希望它有所帮助。

尽管行数为0，但在sql查询中需要单行

4 个答案: