FoxPro Linked Server And Passing Variable Within OPENQUERY

I'm posting this because I found this solution after much digging.

The goal here is to incorporate a variable parameter within a OPENQUERY and, ultimately build a dynamic Where clause for use within a OPENQUERY linked server routine. I'm posting because I spent a lot of time trying to get this to work and also, have seen other posts here that hinted it wasn't doable.

First of all - there a good quick article that gets close for FoxPro and possibly works as is for ACCESS:

http://support.microsoft.com/default.aspx?scid=kb;en-us;314520

Here's code for a solution:

DECLARE @OPENQUERY nvarchar(4000),
@TSQL nvarchar(4000),
@FAMILY CHAR(10)

SET @FAMILY='Touring'
SET @OPENQUERY = 'SELECT * FROM OPENQUERY(VFP,'''

SET @TSQL = 'select cov,family,model from vinmast where family='+'['+@FAMILY+']'')'

EXEC (@OPENQUERY+@TSQL)

All shown are single quotes.

In Visual Foxpro, ' ' or " " or [ ] can be used a delimeters

In addition, if wanting to build a dynamic where clause, you could do something like:

SET @TSQL = 'select cov,family,model from vinmast '
IF <some condition met to include FAMILY filter>
Begin
SET @TSQL=@TSQL+'where family=['+@DUTFAMILY+']'''
SET @TSQL=@TSQL+ ')'
End
-----------------
Here's the entire Stored Procedure:


CREATE PROCEDURE dbo.ewo_sp_DUTLookup
(
@DUTPROJECT char(25)=NULL,--Project
@DUTFAMILY char(10)=NULL,--Family
@DUTMODEL char(20)=NULL,--Model
@DUTYEAR char(4)=NULL,--Model Year
@DUTBEGIN char(25)=NULL,--Beginning of COV/DUT number
@DEBUG int=0
)


AS

DECLARE @OPENQUERY varchar(4000),
@TSQL varchar(4000),
@TWHERE varchar(4000),
@intErrorCode int

select @intErrorCode = @@ERROR,
@TSQL='',
@TWHERE=''


IF @intErrorCode=0
Begin
SET @OPENQUERY = 'SELECT * FROM OPENQUERY(VFP,'''
SET @TSQL = ' select dut_pk,cov,family,model,project,modelyr from vinmast '
End

set @intErrorCode = @@ERROR

IF @intErrorCode = 0 and
@DUTFAMILY is not NULL or
@DUTMODEL is not NULL or
@DUTPROJECT is not NULL or
@DUTYEAR is not NULL or
@DUTBEGIN is not NULL
set @TWHERE=' where '



-- Check for Family criteria
If @intErrorCode = 0 and @DUTFAMILY is not NULL and Len(@TWHERE)>0
SET @TWHERE=@TWHERE+' family=['+@DUTFAMILY+'] AND '
set @intErrorCode = @@ERROR

-- Check for Model criteria
If @intErrorCode = 0 and @DUTMODEL is not NULL and Len(@TWHERE)>0
SET @TWHERE=@TWHERE+' model=['+@DUTMODEL+'] AND '
set @intErrorCode = @@ERROR

--Check for Project criteria
If @intErrorCode = 0 and @DUTPROJECT is not NULL and Len(@TWHERE)>0
SET @TWHERE=@TWHERE+' project=['+@DUTPROJECT+'] AND '
set @intErrorCode = @@ERROR

--Check for Model Year
If @intErrorCode = 0 and @DUTYEAR is not NULL and Len(@TWHERE)>0
SET @TWHERE=@TWHERE+' modelyr=['+@DUTYEAR+'] AND '
set @intErrorCode = @@ERROR

--Check for beginning of DUT
If @intErrorCode = 0 and @DUTBEGIN is not NULL and Len(@TWHERE)>0
Begin
SET @DUTBEGIN=RTRIM(@DUTBEGIN)
SET @TWHERE=@TWHERE+' substr(cov,1,'+cast(len(@DUTBEGIN) as char(20))+')=['+@DUTBEGIN+'] AND '
End
set @intErrorCode = @@ERROR


IF @intErrorCode=0 AND substring(@TWHERE,Len(@TWHERE)-3,4)=' AND '
Begin
set @TWHERE=Substring(@TWHERE,1,Len(@TWHERE)-3)
select @intErrorCode=@@ERROR
End



SET @TWHERE=@TWHERE+''')'

IF @debug<>0 and @intErrorCode=0
Begin
print @intErrorCode
print @OPENQUERY
print @TSQL
print @TWHERE
print @OPENQUERY+@TSQL+@TWHERE
End

IF @intErrorCode=0
EXEC (@OPENQUERY+@TSQL+@TWHERE)
GO

Peter