You have a set of data, and you want to execute a set of queries on the records in a SQL table which are matching with this set of data. You have got a list of Product IDs from the QA department, you need to get the details of those products from the SQL table. And this situation happens frequently. How would you do this? What are the options you have?

Easy solution – You would write select query and put product ID in where clause and get the details. Do this for all the product IDs you have got. Its a time consuming task.
Is there any better way of achieving it where we can get the result in one query?
 
Solution
Yes, we can write a stored procedure, or you can just prepare a set of queries together to run for a single time also.
 
We will use temporary table variable to create arrays in SQL. We will insert the set of data (what you already have) into a temporary array variable. Use While clause, insert into clauses to generate our result table – which will show details of products matching product IDs.
 
Below is a sample set of queries which generates array variable named MYARRAY, you can store your data in this array. Then we will iterate through these array values using WHILE clause, we have used two variables to loop through array – INDEXVAR and TOTALCOUNT. As usual the loop will continue until INDEXVAR is smaller than TOTALCOUNT.
 
Using INDEXVAR and Where clause we will get current array index value. We will use this value to fetch data from actual table and insert it into our temporary result table PRODUCTDETAILSTABLE.
    Use DATABASENAME  
    GO  
      
    DECLARE @PRODUCTDETAILSTABLE table (PRODUCTNAME nvarchar(100), PRODUCTID int, PRODUCTCOST int)  
      
    -- Declare your array table variable  
    DECLARE @MYARRAY table (TEMPCOL nvarchar(50), ARRAYINDEX int identity(1,1) )  
      
    -- Add values to your array table, these are the values which you need to look for in your database  
    INSERT INTO @MYARRAY (TEMPCOL)  
       VALUES  
    ('PRD-2222'), ('PRD-3333'), ('PRD-4563'), ('PRD-4569'), ('PRD-6657'), ('PRD-3452'), ('PRD-6578')  
      
    --select * from @MYARRAY  
      
    DECLARE @INDEXVAR int  
    DECLARE @TOTALCOUNT int  
    DECLARE @CURINDEXEDPRODUCTID nvarchar (50)  
    SET @INDEXVAR = 0  
    SELECT @TOTALCOUNT= COUNT(*) FROM @MYARRAY  
    WHILE @INDEXVAR < @TOTALCOUNT  
    BEGIN  
        SELECT @INDEXVAR = @INDEXVAR + 1  
      
        -- Get value of current indexed product ID from array table  
        SELECT @CURINDEXEDPRODUCTID = TEMPCOL from @MYARRAY where ARRAYINDEX = @INDEXVAR  
      
        -- Get details of Product matching current indexed product ID from array  
        BEGIN  
            INSERT INTO @PRODUCTDETAILSTABLE (PRODUCTNAME, PRODUCTID, PRODUCTCOST)  
            (  
                select top 1 ProductName as PRODUCTNAME, ProductID as PRODUCTID, Cost as PRODUCTCOST  
                FROM  
                dbo.ProductDetails t  
                where t.ProductID= @CURINDEXEDPRODUCTID  
            )   
        END  
    END  
      
    Select * from @PRODUCTDETAILSTABLE  

You might come across a scenario where you need to update a set of records from your database or delete specific rows from your table – at that time you might need these array queries to fulfill your requirements. That’s it for this article. When someone asks you to pull data for specific list of IDs then I hope these queries help you to pull out data easily from the database.