asked on

using variables in whereclause

Hi,
I have something like below in my stored procedure

IF @physicianID = 0 OR @physicianID IS NULL
BEGIN
SET @whereClause = 'requestedby=@physicianID
            and examdate>=@startDate
            and examdate<=@endDate'
END
ELSE
BEGIN
SET @whereClause ='examdate>=@startDate
            and examdate<=@endDate'
END

and I used the variable @whereCluase like below

select
            examdate,
            patient_no
      from exams
      where @whereClause
      group by examdate,patient_no
Can I do like this? or please let me know how can I do that .

Thank you

HainKurt

after your code do his

declare @sql varchar(max) = 'select ... from ...' + @whereClause
exec @sql

HainKurt

oops, you need to work on this part too

SET @whereClause = 'requestedby=@physicianID
and examdate>=@startDate
and examdate<=@endDate'
>>>>
SET @whereClause = 'requestedby=' + @physicianID +
' and examdate>= ''' + @startDate + ''''
' and examdate<= ''' + @endDate + ''''

HainKurt

and I guess there is logical error in your code "if... then ... else..." logic should be reversed...

so, final structure should be something like this

declare @whereClause varchar(max)
declare @startDate varchar(12)
declare @endDate varchar(12)
declare @physicianID int

IF isNull(@physicianID,0) = 0
BEGIN 
  SET @whereClause ='examdate >= ''' + @startDate + ''' and examdate <= ''' + @endDate + ''''
END
ELSE
BEGIN
  SET @whereClause = 'requestedby=' + @physicianID + ' and examdate>= ''' + @startDate + ''' and examdate<= ''' + @endDate + ''''
END

declare @sql varchar(max) = 'select ... from ...' + @whereClause
exec @sql

Open in new window

Scott Pletcher

You have two choices:
1. Use one query, which tests the variable and column as needed.
This may not produce an optimal query plan every time it run.
2. Use dynamic SQL, which will produce an optimal query plan, but is more work
to set up **and requires specific authorities being granted *directly* to the id
used to run the SQL code**.

--1.
SELECT
examdate,
patient_no
FROM dbo.exams
WHERE
(@physicianID = 0 OR @physicianID IS NULL OR requestedby = @physicianID) AND
examdate>=@startDate and
examdate<=@endDate'
GROUP BY
examdate, patient_no

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Scott Pletcher

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Sthokala

ASKER

Hi,
Thank you for your comments. I tried below way

DECLARE @sql nvarchar(max)

SET @sql = ' INSERT INTO #TmpMUStatus
SELECT count(*), (SELECT name from users where user_no='+CAST(@physicianID AS varchar(10))+') as physicianName,null,null,null,null,null,null,null,null,null,null,NULL,NULL from(
      SELECT
            examdate,
            patient_no
      FROM exams WHERE
examdate>='+LEFT(CONVERT(VARCHAR, @startDate, 120), 10)
+' AND
examdate<='+LEFT(CONVERT(VARCHAR, @endDate, 120), 10)

IF @physicianID > 0
SET @sql = @sql + ' AND
requestedby = ' + CAST(@physicianID AS varchar(10))

SET @sql = @sql + '
GROUP BY examdate,patient_no) AS SourceQuery'
EXEC @sql

I am getting below error

Msg 203, Level 16, State 2, Procedure GenerateMUStats, Line 54
The name ' INSERT INTO #TmpMUStatus
SELECT count(*), (SELECT name from users where user_no=73408) as physicianName,null,null,null,null,null,null,null,null,null,null,NULL,NULL from(
      SELECT
            examdate,
            patient_no
      FROM exams WHERE
examdate>=2012-01-01 AND
examdate<=2012-05-05 AND
requestedby = 73408
GROUP BY examdate,patient_no) AS SourceQuery' is not a valid identifier.

Scott Pletcher

EXEC (@sql) -- the parens are required

Since you want pass to the date values in, you also need additional quotes:

...
FROM exams WHERE
examdate>='''+LEFT(CONVERT(VARCHAR, @startDate, 112), 8)
+''' AND
examdate<='''+LEFT(CONVERT(VARCHAR, @endDate, 112), 8) + ''''
...