Avoid "copy&paste" method for stored procedure depending on parameter - sql

Question

I have 50 stored procedures that I need to add a new location to. Is there an alternative for writing my stored procedures in the following way? (where I copy the same select statement for each location)
IF #LOCATION = 'Canada'
BEGIN
SELECT location_id, location_description
INTO #tempAssetHistoryCANADA
FROM [SERVER20].[Shop_Canada].[dbo].[report_asset_history]
END
IF #LOCATION = 'USA'
BEGIN
SELECT location_id, location_description
INTO #tempAssetHistoryUSA
FROM [SERVER20].[Shop_USA].[dbo].[report_asset_history]
END
I have a select statement that fires if the #parameter = "x" And then the exact same select statement, but from a different data source with the same structure if #parameter = "y".
I'm wondering if there is a better way to write these stored procedures because in the future when I need to add a new location I will need to update all 50 stored procedures, and copy each statement and slightly alter it for the new locations data? I've researched around and haven't found anything helpful.
Thanks!

Answer 1

One possible way instead of using a dynamical query is to create a view:
CREATE VIEW dbo.Locations
AS
SELECT location_id, location_description, 'Canada' AS location
FROM [SERVER20].[Shop_Canada].[dbo].[report_asset_history]
UNION ALL
SELECT location_id, location_description, 'USA' AS location
FROM [SERVER20].[Shop_USA].[dbo].[report_asset_history]
And then using it:
SELECT location_id, location_description
INTO #tempAssetHistory
FROM [dbo].Locations
WHERE location = #LOCATION
If you have new tables [SERVER20].[Shop_XXX].[dbo].[report_asset_history] you will have to add them to your view.

Answer 2

Put the code that loads the temp table into table-valued function. Then call this function from all your other SPs that need the data
SELECT * INTO #TempAssetHistory FROM dbo.LoadTempAssetHistory(#Location)
:
: Use the data
:
The LoadTempAssetHistory SP would look something like (CODE NOT TESTED):
CREATE FUNCTION LoadTempAssetHistory
(
#LOCATION Varchar(50)
)
RETURNS TABLE
AS
RETURN
(
SELECT location_id, location_description
FROM [SERVER20].[Shop_Canada].[dbo].[report_asset_history]
WHERE #LOCATION='CANADA'
UNION
SELECT location_id, location_description
FROM [SERVER20].[Shop_USA].[dbo].[report_asset_history]
WHERE #LOCATION = 'USA'
)
Now you can amend the function when you have a new location (or decide to reorganise all your data) without needing to change 50 SPs.

Answer 3

First of all you don't need a different #temp table for each location. You're storing the same data columns in each. Secondly, you could store the "From" clause in a table based on location and then use dynamic sql to select into your temp table. I'll provide some code and example shortly.
DECLARE #fromClause VARCHAR(255)
DECLARE #sql VARCHAR(MAX)
--Explicitly create the temp table
CREATE TABLE #T (location_id int, location_description varchar(255) )
--Get the FROM clause
select #fromClause = fromClause from tblLocation WHERE location = #LOCATION
--Build the Dynamic SQL
SET #sql = 'SELECT location_id, location_description ' + #fromClause
--Insert into your temp table
INSERT INTO #T execute ( #sql )
--View the results
SELECT * FROM #T
Here is tblLocation definition

Answer 4

You could achieve this by having a #Temp table for all your assists and checking against a location table in your DB, then calling the variable when the SP is executed:
Call the SP:
SP_Some_SP 'Canada'
Inside the SP
Declare #Location Varchar(100)
Declare #Location_ID int = (Select Location_ID from [Location] where Location_Description = #Location)
CREATE TABLE #TempAssetHistory
(
location_ID int,
location_Description varchar(100)
)
If Exists(Select Location_Description from [Location] where Location_Description = #Location )
BEGIN
Insert INTO #TempAssetHistory
Values(#Location_ID,#Location)
END
ELSE
BEGIN
-- Do something
END

Answer 5

You can use one table to store all selected data, use something like this:
DECLARE #country VARCHAR(20) = 'USA'
CREATE TABLE #tempHistory (country varchar(20), location_id int, location_description varchar(20))
DECLARE #sql VARCHAR(max)
SET #sql = 'SELECT ''' + #country + ''' as country, location_id, location_description FROM [SERVER20].[Shop_' + #country + '].[dbo].[report_asset_history]'
INSERT INTO #tempHistory EXEC (#sql)
Or you can use more flexible solution to put the list of countries as a parameter:
CREATE PROCEDURE dbo.prepare_tempHistory(#listOfCountries VARCHAR(max))
AS
DECLARE #sql varchar(max)
SET #sql = ''
SELECT #sql = #sql + ' UNION ALL ' +
'SELECT ''' + val + ''' as country, location_id, location_description FROM [SERVER20].[Shop_' + val + '].[dbo].[report_asset_history]'
FROM dbo.fnSplit(#listOfCountries, ',')
SET #sql = RIGHT(#sql, len(#sql)-11)
INSERT INTO #tempHistory EXEC (#sql)
GO
but then you need a small function to split parameters into table:
CREATE FUNCTION dbo.fnSplit
(
#delimited nvarchar(max),
#delimiter nvarchar(5)
)
RETURNS #ret TABLE (val nvarchar(max))
AS
BEGIN
declare #xml xml
set #xml = N'<root><r>' + replace(#delimited,#delimiter,'</r><r>') + '</r></root>'
insert into #ret(val)
select r.value('.','varchar(max)') as item
from #xml.nodes('//root/r') as records(r)
RETURN
END
GO
Now you can prepare data on easy way:
CREATE TABLE #tempHistory (country varchar(20), location_id int, location_description varchar(20))
EXEC dbo.prepare_tempHistory 'USA,Canada,Mexico'
SELECT * FROM #tempHistory
for any additional country modify only the parameter

Answer 6

using suggestions from the answers and comments mentioning Dynamic SQL I came up with this little solution for myself. It's nicer then what Denis Rubashkin said because using his solution I would still have to copy the entire SQL query every time a new location is added. This way, I can just copy the 4 lines...
IF #LOCATION = 'CANADA'
BEGIN
SET #location_server = 'SHOP_Canada'
END
...from the IF statement at the beginning whenever I want to add a new location, not the whole SQL statement. It will replace the server name with the correct name in the parameter and append its name to the temp tables.
#LOCATION varchar(50),
#sqlCommand nvarchar(2000),
#location_server varchar(75)
IF #LOCATION = 'CANADA'
BEGIN
SET #location_server = 'SHOP_Canada'
END
IF #LOCATION = 'USA'
BEGIN
SET #location_server = 'SHOP_USA'
END
SET #sqlCommand = 'SELECT location_id, location_description
into ##MarineShopAssetExpensesLTD_'+#location_server+'
FROM [SERVER20].'+QUOTENAME(#location_server)+'.[dbo].[report_asset_history]
INNER JOIN [SERVER20].'+QUOTENAME(#location_server)+'.[dbo].imtbl_asset ON [report_asset_history].asset_id = imtbl_asset.id
GROUP BY location_id, location_description
EXECUTE sp_executesql #sqlCommand

Answer 7

As every SP is looking for different data, there is another, somewhat more drastic approach that you could use.
This approach requires that you put all the data SELECT statements for all 50 SPs into a single SP, say spDataLoad, which takes two parameters - a data set name and the location. The spDataLoad selects data based on which data set and which location are specified, and returns that requested data to the caller.
You will still need multiple select statements for each different combination of data set and location, but at least everything is in one single SP, and changes to the data will not affect all 50 SPs. If the tables and data for each location are the same, then you can subdivide the code into sections, one for each location, with identical code except for the database name corresponding to the location.
Using the code above as an example, if we choose 'AssetHistory' as the data set name then the code in your existing SPs would look like this:
:
:
CREATE TABLE #AssetHistory (
location_ID int,
location_Description varchar(100)
);
INSERT INTO #AssetHistory EXEC spDataLoad #DataSet='AssetHistory', #Location=#Location;
:
: use the data set
:
Now suppose you have another SP that requires the data set 'AssetDetails' then the code would be like this:
CREATE TABLE #AssetDetails (
:
: Specification for Asset Details table
:
);
INSERT INTO #AssetDetails EXEC spDataLoad #DataSet='AssetDetails', #Location=#Location;
:
: use the data set
:
The stored procedure spDataLoad, with multiple sections, for each of the locations, with separate selects based on the requested data set might look like this:
CREATE PROCEDURE spDataLoad
#DATASET varchar(20)
, #LOCATION Varchar(50)
AS
BEGIN
-- CANADA SECTION ------------------------------------
IF #LOCATION = 'CANADA'
BEGIN
IF #DATASET = 'AssetHistory'
SELECT location_id, location_description
FROM [SERVER20].[Shop_Canada].[dbo].[report_asset_history]
ELSE IF #DATASET = 'AssetDetails'
SELECT
: Asset details data
FROM [SERVER20].[Shop_Canada].[dbo].[report_asset_details]
ELSE IF #DATASET = '....'
:
: Etc, Etc for CANADA SECTION
END;
-- USA SECTION ------------------------------------
IF #LOCATION = 'USA'
BEGIN
IF #DATASET = 'AssetHistory'
SELECT location_id, location_description
FROM [SERVER20].[Shop_USA].[dbo].[report_asset_history]
ELSE IF #DATASET = 'AssetDetails'
SELECT
: Asset details data
FROM [SERVER20].[Shop_USA].[dbo].[report_asset_details]
ELSE IF #DATASET = '....'
:
: Etc, Etc for USA SECTION
END;
-- SOME OTHER SECTION ---------------------------
IF #LOCATION = 'SOME OTHER'
BEGIN
: Same logic
END
RETURN 0;
END
To manage performance you would probably need to add defaulted parameters for filtering which can be specified by the caller, and add WHERE clauses into the data set selections.