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Passing multiple/dynamic values to Stored Procedures & Functions | Part 5 – by passing JSON string

October 31, 2015 3 comments

This post is part of the [Passing multiple/dynamic values to Stored Procedures & Functions] series, and as well as the new feature Native JSON support in SQL Server 2016.

Adding the fifth part to this series we will use JSON string that will contain the set of values and pass as an JSON param variable to the SP. Then inside the SP we will parse this JSON and use those values in our SQL Queries, just like we did in previous posts with CSV/XML strings:

USE [AdventureWorks2014]
GO

-- Create an SP with NVARCHAR type parameter for JSON string:
CREATE PROCEDURE uspGetPersonDetailsJSON (
	@persons NVARCHAR(MAX)
)
AS
BEGIN
	--DECLARE @persons NVARCHAR(MAX)
	--SET @persons = '{"root":[{"Name":"Charles"},{"Name":"Jade"},{"Name":"Jim"},{"Name":"Luke"},{"Name":"Ken"}]}'
	
	SELECT Name
	INTO #tblPersons
	FROM OPENJSON (@persons, '$.root')
	WITH ( 
		Name NVARCHAR(100)
	)

	SELECT 
		BusinessEntityID, 
		Title, 
		FirstName, 
		MiddleName, 
		LastName, 
		ModifiedDate
	FROM [Person].[Person] PER
	WHERE EXISTS (
		SELECT * 
		FROM #tblPersons tmp 
		WHERE tmp.Name  = PER.FirstName
	)
	ORDER BY FirstName, LastName

	DROP TABLE #tblPersons
END
GO

-- Create JSON string:
DECLARE @json NVARCHAR(1000)
SET @json = N'{
  "root": [
    { "Name": "Charles" },
    { "Name": "Jade" },
    { "Name": "Jim" },
    { "Name": "Luke" },
    { "Name": "Ken" }
  ]
}'

-- Use the JSON string as parameter which calling the SP:
EXEC uspGetPersonDetailsJSON @json
GO

-- Check the output, objective achieved

-- Final Cleanup
DROP PROCEDURE uspGetPersonDetailsXML
GO

 

Thus you can also use JSON string similar to the way you used XML string, to pass multiple and dynamic number of parameters to your Stored Procedures.

As JSON feature is new to SQL Server 2016, so this method will only work with SQL Server 2016 and above versions.
 


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Pass an array of multiple values with a single Parameter in a Stored Procedure – SQL Server

July 10, 2015 3 comments

This post comes from an old discussion on MSDN T-SQL Forum[link], where someone asked about the same topic.

Check my reply there and here with this post I’m going to collate all the different methods I’ve blog previously that can be used for the same purpose.
 

Stored Procedures accept only a fixed and pre-defined number of parameters thus there is a limitation you cannot provide dynamic number of params, like you can do with other languages, like C, C#, Java, etc. In these languages there is concept of Arrays which you can pass in a method/function, but in SQL there are no array variables and it does not have any datatype that support arrays. Thus if you have to provide multiple values to any parameter you cannot do it directly, though there are some workarounds.
 

–> Here are some of the methods or workarounds by which we can pass multiple values as a single Parameter in a Stored Procedure or a Function:

Method #1 – Passing a CSV: list of strings as a parameter to a (N)VARCHAR datatype parameter, then splitting/parsing it inside the SP or UDF, check here.

Method #2 – Passing an XML: string as an XML datatype parameter. We will need to parse the XML inside the SP, check here.

Method #3 – Using a temp table: inside an SP which is created outside just before its execution. Here there is no need to pass any parameter with the SP, check here.

Method #4 – Using TVPs: With SQL Server 2008 and above you can create TVPs or Table Valued Parameters and declare them by using user-defined table types. These TVPs can then be used to send multiple rows of data to SPs or UDFs, without creating a temp table or multiple parameters, check here.

Method #5 – Passing a JSON string: as a NVARCHAR datatype parameter. We will need to parse the JSON inside the SP, check here.
 

Thanks a lot, please provide your valuable comments and suggestions on this topic.
 

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Passing multiple/dynamic values to Stored Procedures & Functions | Part 4 – by using TVP

September 10, 2012 2 comments

This is the last fourth part of this series, in previous posts we talked about passing multiple values by following approaches: CSV, XML, #table. Here we will use a new feature introduced in SQL Server 2008, i.e. TVP (Table Valued Parameters).
 

As per MS BOL, TVPs are declared by using user-defined table types. We can use TVPs to send multiple rows of data to Stored Procedure or Functions, without creating a temporary table or many parameters. TVPs are passed by reference to the routines thus avoiding copy of the input data.
 

Let’s check how we can make use of this new feature (TVP):

-- First create a User-Defined Table type with a column that will store multiple values as multiple records:
CREATE TYPE dbo.tvpNamesList AS TABLE 
(
	Name NVARCHAR(100) NOT NULL,
    PRIMARY KEY (Name)
)
GO

-- Create the SP and use the User-Defined Table type created above and declare it as a parameter:
CREATE PROCEDURE uspGetPersonDetailsTVP (
	@tvpNames tvpNamesList READONLY
)
AS
BEGIN
	
	SELECT BusinessEntityID, Title, FirstName, MiddleName, LastName, ModifiedDate
	FROM [Person].[Person] PER
	WHERE EXISTS (SELECT Name FROM @tvpNames tmp WHERE tmp.Name  = PER.FirstName)
	ORDER BY FirstName, LastName

END
GO

-- Now, create a Table Variable of type created above:
DECLARE @tblPersons AS tvpNamesList

INSERT INTO @tblPersons
SELECT Names FROM (VALUES ('Charles'), ('Jade'), ('Jim'), ('Luke'), ('Ken') ) AS T(Names)

-- Pass this table variable as parameter to the SP:
EXEC uspGetPersonDetailsTVP @tblPersons
GO
-- Check the output, objective achieved 🙂


-- Final Cleanup
DROP PROCEDURE uspGetPersonDetailsTVP
GO

 

So, we saw how we can use TVPs with Stored Procedures, similar to this they are used with UDFs.

TVPs are a great way to pass array of values as a single parameter to SPs and UDFs. There is lot of know and understand about TVP, their benefits and usage, check this [link].


Passing multiple/dynamic values to Stored Procedures & Functions | Part 3 – by using #table

September 9, 2012 3 comments

In my previous posts we saw how to pass multiple values to an SP by using CSV list and XML data, which are almost of same type. Here in this post we will see how we can achieve the same objective without passing values as parameters and by using temporary (temp, #) tables.

Here in the third part of this series the Stored Procedure will be created in such a way that it will use a Temporary Table, which does not exist in compile time. But at run time the temp-table should be created before running the SP. In this approach there is no need to pass any parameter with the SP, let’s see how:

-- Create Stored Procedure with no parameter, it will use the temp table created outside the SP:
CREATE PROCEDURE uspGetPersonDetailsTmpTbl
AS
BEGIN
	
	SELECT BusinessEntityID, Title, FirstName, MiddleName, LastName, ModifiedDate
	FROM [Person].[Person] PER
	WHERE EXISTS (SELECT Name FROM #tblPersons tmp WHERE tmp.Name  = PER.FirstName)
	ORDER BY FirstName, LastName

END
GO

-- Now, create a temp table, insert records with same set of values we used in previous 2 posts:
CREATE TABLE #tblPersons (Name NVARCHAR(100))

INSERT INTO #tblPersons
SELECT Names FROM (VALUES ('Charles'), ('Jade'), ('Jim'), ('Luke'), ('Ken') ) AS T(Names)

-- Now execute the SP, it will use the above records as input and give you required results:
EXEC uspGetPersonDetailsTmpTbl
-- Check the output, objective achieved 🙂

DROP TABLE #tblPersons
GO

-- Final Cleanup
DROP PROCEDURE uspGetPersonDetailsTmpTbl
GO

This approach is much better than the previous 2 approaches of using CSV or XML data.

The values will be entered in temp tables and then will be accessed inside the SP. There is no parsing involved as the records are directly read from temp table and used in SQL query just like normal queries. Also there is no limit of records if you compare with CSVs & XML data.

But, the catch here is, the temp table should exist before executing the SP, if for some reason it is not there the code will crash. But its rare and can be handled by some checks.

In my next and last [blog post] of this series we will see a new feature of SQL Server 2008 i.e. TVP, which can be used in such type of scenarios, check here.

Passing multiple/dynamic values to Stored Procedures & Functions | Part 2 – by passing XML

September 9, 2012 4 comments

In my previous post [Part 1] we saw how to pass multiple values to a parameter as a CSV string in an SP.
 

Here in the second part of this series we will use XML string that will contain the set of values and pass as an XML param variable to the SP. Then inside the SP we will parse this XML and use those values in our SQL Queries, just like we did in previous post with CSV string:

USE [AdventureWorks2012]
GO

-- Create an SP with XML type parameter:
CREATE PROCEDURE uspGetPersonDetailsXML (
	@persons XML
)
AS
BEGIN
	--DECLARE @persons XML
	--SET @persons = '<root><Name>Charles</Name><Name>Jade</Name><Name>Jim</Name><Name>Luke</Name><Name>Ken</Name></root>'

	SELECT T.C.value('.', 'NVARCHAR(100)') AS [Name]
	INTO #tblPersons
	FROM @persons.nodes('/root/Name') as T(C)
	
	SELECT BusinessEntityID, Title, FirstName, MiddleName, LastName, ModifiedDate
	FROM [Person].[Person] PER
	WHERE EXISTS (SELECT Name FROM #tblPersons tmp WHERE tmp.Name  = PER.FirstName)
	ORDER BY FirstName, LastName

	DROP TABLE #tblPersons
END
GO

-- Create XML string:
DECLARE @xml XML
SET @xml = '<root>
				<Name>Charles</Name>
				<Name>Jade</Name>
				<Name>Jim</Name>
				<Name>Luke</Name>
				<Name>Ken</Name>
			</root>'

-- Use the XML string as parameter which calling the SP:
EXEC uspGetPersonDetailsXML @xml
GO
-- Check the output, objective achieved 🙂

-- Final Cleanup
DROP PROCEDURE uspGetPersonDetailsXML
GO

 

This approach looks much cleaner and more stable to me than the previous one (CSV). XML is a de-facto standard to store and transmit data in a more structured way. Thus I prefer XML string over the CSV string on these type of cases.
 

The CSV approach is no different than this one, it internally converts the CSV string to an XML then parse it. Thus, like CSV if the XML string becomes lengthy it will also take time to parse the whole XML and then use the values in SQL queries in the SP.
 

In next [blog post] we will see how we can perform the same operation by using temporary (temp, #) tables.