Expand row results based on a value in column (with iterator)
Need help from you all in writing up this query. Running SQL 2005 Standard edition.
I have a basic query that gets a subset of records from a table where the record_Count is greater then 1.
SELECT *
FROM Table_Records
WHERE Record_Count > 1
This query gives me a result set of, say:
TableRecords_ID Record_Desc Record_Count
123 XYZ 3
456 PQR 2
The above query needs to be modified so that each record appears as many times as the Record_Count and has its iteration number with it, as a value. So the new query should return results as follows:
TableRecords_ID Record_Desc Record_Count 开发者_如何学C Rec_Iteration
123 XYZ 3 1
123 XYZ 3 2
123 XYZ 3 3
456 PQR 2 1
456 PQR 2 2
Could anyone help we write this query up? appreciate the help.
Clarification: Rec_Iteration column is a sub representation of the Record_Count. Basically, since there are three Record_Count for XYZ description thus three rows were returned with the Rec_Iteration representing the Row one , two and three respectively.
You can use a recursive CTE for this query. Below I use a table variable @T
instead of your table Table_Records
.
declare @T table(TableRecords_ID int,Record_Desc varchar(3), Record_Count int)
insert into @T
select 123, 'XYZ', 3 union all
select 456, 'PQR', 2
;with cte as
(
select TableRecords_ID,
Record_Desc,
Record_Count,
1 as Rec_Iteration
from @T
where Record_Count > 1
union all
select TableRecords_ID,
Record_Desc,
Record_Count,
Rec_Iteration + 1
from cte
where Rec_Iteration < Record_Count
)
select TableRecords_ID,
Record_Desc,
Record_Count,
Rec_Iteration
from cte
order by TableRecords_ID,
Rec_Iteration
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