SQL server stored procedure return a table

Question

I have a stored procedure that takes in two parameters. I can execute it successfully in Server Management Studio. It shows me the results which are as I expect. However it

Answer 1

Consider creating a function which can return a table and be used in a query.

https://msdn.microsoft.com/en-us/library/ms186755.aspx

The main difference between a function and a procedure is that a function makes no changes to any table. It only returns a value.

In this example I'm creating a query to give me the counts of all the columns in a given table which aren't null or empty.

There are probably many ways to clean this up. But it illustrates a function well.

USE Northwind

CREATE FUNCTION usp_listFields(@schema VARCHAR(50), @table VARCHAR(50))
RETURNS @query TABLE (
    FieldName VARCHAR(255)
    )
BEGIN
    INSERT @query
    SELECT
        'SELECT ''' + @table+'~'+RTRIM(COLUMN_NAME)+'~''+CONVERT(VARCHAR, COUNT(*)) '+
    'FROM '+@schema+'.'+@table+' '+
          ' WHERE isnull("'+RTRIM(COLUMN_NAME)+'",'''')<>'''' UNION'
    FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = @table and TABLE_SCHEMA = @schema
    RETURN
END

Then executing the function with

SELECT * FROM usp_listFields('Employees')

produces a number of rows like:

SELECT 'Employees~EmployeeID~'+CONVERT(VARCHAR, COUNT(*)) FROM dbo.Employees  WHERE isnull("EmployeeID",'')<>'' UNION
SELECT 'Employees~LastName~'+CONVERT(VARCHAR, COUNT(*)) FROM dbo.Employees  WHERE isnull("LastName",'')<>'' UNION
SELECT 'Employees~FirstName~'+CONVERT(VARCHAR, COUNT(*)) FROM dbo.Employees  WHERE isnull("FirstName",'')<>'' UNION