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How to write a foreach in SQL Server? Ask Question

tag-icon • tag-icon sql-server t-sql
How to write a foreach in SQL Server? Ask Question

I am trying to achieve something along the lines of a for-each, where I would like to take the Ids of a returned select statement and use each of them.

DECLARE @i int
DECLARE @PractitionerId int
DECLARE @numrows int
DECLARE @Practitioner TABLE (
    idx smallint Primary Key IDENTITY(1,1)
    , PractitionerId int
)

INSERT @Practitioner
SELECT distinct PractitionerId FROM Practitioner

SET @i = 1
SET @numrows = (SELECT COUNT(*) FROM Practitioner)
IF @numrows > 0
    WHILE (@i <= (SELECT MAX(idx) FROM Practitioner))
    BEGIN

        SET @PractitionerId = (SELECT PractitionerId FROM @Practitioner WHERE idx = @i)

        --Do something with Id here
        PRINT @PractitionerId

        SET @i = @i + 1
    END

At the moment I have something that looks like the above, but am getting the error:

Invalid column name 'idx'.

ベストアンサー1

を使用したいと考えていますCURSOR。ほとんどの場合、セット ベースのソリューションを使用するのが最適ですが、 がCURSOR最適なソリューションである場合もあります。実際の問題について詳しく知らなければ、それ以上のサポートはできません。

DECLARE @PractitionerId int

DECLARE MY_CURSOR CURSOR 
  LOCAL STATIC READ_ONLY FORWARD_ONLY
FOR 
SELECT DISTINCT PractitionerId 
FROM Practitioner

OPEN MY_CURSOR
FETCH NEXT FROM MY_CURSOR INTO @PractitionerId
WHILE @@FETCH_STATUS = 0
BEGIN 
    --Do something with Id here
    PRINT @PractitionerId
    FETCH NEXT FROM MY_CURSOR INTO @PractitionerId
END
CLOSE MY_CURSOR
DEALLOCATE MY_CURSOR

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