如何使用递归查询构造SQL数据透视表

Question

想象我有这些表

WorkOrder：

[Id], [ServiceId], [StatusId]

服务

[Id], [SName], [SCode], [SDnaCode], [SerivceParentId:Nullable]

状态

[Id], [StName], [StCode]

现在如何获得这样的数据透视表结果：

|StName   |RootService_1|RootService_2|...
+---------+-------------+-------------+----
|Initiated|23           |12           |...
|Closed   |8            |5            |...

请记住，计数数是针对根服务的，并且它是每个根服务的自己的层次结构

[Service]表中的示例记录

|ID|SName        |SCode|SDnaCode|SerivceParentId|
+--+-------------+-----+--------+---------------+
| 1|RootService_1|RS01 |RS01    |NULL           |
| 2|RS01_Child_1 |C01  |RS01.C01|1              |
| 3|RS01_Child_2 |C02  |RS01.C02|1              |
| 4|RootService_2|RS02 |RS02    |NULL           |
| 5|RS02_Child_1 |C01  |RS02.C01|2              |
| 6|RS02_Child_2 |C02  |RS02.C02|2              |

因此，示例数据透视表中23下的数字RootService_1是Initiated WorkOrder的计数，其中ServiceId的1,2或3组合在一起

请记住，我想将其包装在动态SQL中以便为数据透视表for clause生成值。

希望我能很好地解释我的问题，在此先感谢

Answer 1

我找到了一个解决方案，我希望找到一个与文本数据较少相关的解决方案此解决方案取决于SDnaCode列，在我的情况下为ServiceDnaCode，我将其设置为存储过程

CREATE PROCEDURE DashboardGetServicesDataByStatus @lvl int, @parentId  NVARCHAR(MAX)
AS
BEGIN

DECLARE 
    @columns NVARCHAR(MAX) = '', 
    @sql     NVARCHAR(MAX) = '',
    @sqlCommand nvarchar(max)=''; 

-- select the StatusName
set @sqlCommand = 'SELECT 
    @columns+=QUOTENAME(
    (SELECT value from string_split(ServiceDnaCode,''.'')
order by CURRENT_TIMESTAMP
OFFSET      @lvl rows
fetch next 1 rows only)) + '',''
FROM 
    [Service] where ParentServiceId' + 
        case
            when @lvl>0 then ' IN(@parentId)'
            else    ' is null '
        end
    + '
ORDER BY 
    Id;';

EXECUTE sp_executesql @sqlCommand, N'@lvl int,@parentId NVARCHAR(max),@columns NVARCHAR(max) OUTPUT'
, @lvl = @lvl,@parentId=@parentId, @columns=@columns OUTPUT

-- remove the last comma
SET @columns = LEFT(@columns, LEN(@columns) - 1);

print @columns
print @lvl

-- construct dynamic SQL
SET @sql ='
with cte_service as (
select * from [Service] where [Service].Id IN ('+CAST(@parentId as varchar(max))+')
union all
select e.* from [Service] e inner join cte_service o on e.ParentServiceId= o.Id
)

SELECT * FROM (
select count(wo.Id) ID,os.StatusName STATENAME ,
(SELECT value from string_split(ServiceDnaCode,''.'')
order by CURRENT_TIMESTAMP
OFFSET      '+CAST(@lvl as varchar(max))+' rows
fetch next 1 rows only) SNAME from WorkOrder wo 
left join RefWorkOrderStatus os on wo.OrderStatusCode=os.Id 
left join [Service] s on wo.MainServiceId=s.Id
where wo.MainServiceId IN (select Id from cte_service)
group by os.StatusName,s.ServiceDnaCode
) t
pivot(
sum(ID)
for SNAME IN ('+ @columns +')
) as pivottable';

-- execute the dynamic SQL
EXECUTE sp_executesql @sql;

END
Go