Creating Unions In TSQL

Hi everyone. I was wondering if I could get some pointers in creating a union between two tables. This is the sproc I currently have:








CREATE Procedure spGetReturnCheckForCriteria





@SearchCriteria VARCHAR(8000),





@SortOrder VARCHAR(8000),





@PageSize INT





AS





-- Declare vars





DECLARE @SQLStatement NVARCHAR(4000)





DECLARE @bldSQLStatement VARCHAR(8000)





DECLARE @retValue INT





-- Initialize vars





SET @SQLStatement = ''





SET @bldSQLStatement = ''





SET @retValue = -1





-- Sanity Check(s)





IF (@PageSize IS NULL OR @PageSize < 1)





-- Paging Size can not be Null, nor less than One





BEGIN





SET @RetValue = -30 -- "Must have a valid Paging Size for pagination: Error (-30)





RETURN





END





-- Build the Paging SQL Statement





SET @bldSQLStatement = 'SELECT TOP '





-- Add the Page Size





SET @bldSQLStatement = @bldSQLStatement + CAST(@PageSize AS VARCHAR)





-- Add Columns/Tables/Relationships





SET @bldSQLStatement = @bldSQLStatement + '





ReturnCheck.ReturnCheckID AS ReturnCheckID,


ReturnCheck.FiscalNumber AS FiscalNumber,


ReturnCheck.ReturnedDate AS ReturnedDate,


ReturnCheck.CheckNumber AS CheckNumber,


ReturnCheck.AssessPenaltyIndicator AS AssessPenaltyIndicator,


ReturnCheck.ReturnCheckCollectionStatusCode AS ReturnCheckCollectionStatusCode,


ReturnCheck.ReturnCheckReasonCode AS ReturnCheckReasonCode,


ReturnCheck.CentralCollectionsID AS CentralCollectionsReferralNumber,


TaxPayment.PaymentID AS PaymentID,


TaxPayment.DocumentLocatorNumber AS DocumentLocatorNumber,


TaxPayment.PaymentEffectiveDate AS PaymentEffectiveDate,


TaxPayment.PaymentAmount AS PaymentAmount,


TaxPayment.PaymentQuarter AS PaymentQuarter,


TaxPayment.PaymentYear AS PaymentYear,


TaxPayment.InternalReferenceNumber AS InternalReferenceNumber,


TaxPayment.PaymentTypeCode AS PaymentTypeCode,


TaxPayment.PaymentOriginCode AS PaymentOriginCode,


TaxPayment.VoucherNumber AS VoucherNumber,


TaxPayment.ReversedIndicator AS ReversedIndicator,


TaxPayment.PaymentDate AS PaymentDate,


CAST(NULL AS DATETIME) AS CCReferralDate,


DistributionPoint.UIDPrime AS UIDPrime,


DistributionPoint.UIDCheck AS UIDCheck,


DistributionPoint.UIDDistPoint AS UIDDistPoint,





CASE





WHEN ReturnCheck.UpdatedDate IS NULL THEN ReturnCheck.CreatedDate





ELSE ReturnCheck.UpdatedDate





END AS ReturnCheckTimeStamp





FROM TaxPayment





INNER JOIN DistributionPoint





ON (TaxPayment.DistributionPointID = DistributionPoint.DistributionPointID)





INNER JOIN ReturnCheck





ON (TaxPayment.PaymentID = ReturnCheck.PaymentID)





'





-- Add Search Criteria





If (@SearchCriteria IS NOT NULL)





SET @bldSQLStatement = @bldSQLStatement + ' WHERE ' + @SearchCriteria





-- Add Sort Order





IF (@SortOrder IS NOT NULL)





SET @bldSQLStatement = @bldSQLStatement + ' ' + @SortOrder





-- Set the SQLStatement





SET @SQLStatement = @bldSQLStatement


-- Execute the Paging Query


EXECUTE @retValue = sp_executeSQL @SQLStatement


GO








Look at the SQL build where I'm doing an INNER JOIN between TaxPayment and RefundCheck. Instead of this INNER JOIN, I'd like to do a union instead. If I can get any help on this I'd greatly appreciate it. Cheers.