使用存储过程对表进行分组

Question

UPDATE - I have figured out how to add the stored procedures using code-first migration. 'All' I am wondering now is how I can apply a SELECT * FROM _tempTable1_ UNION SELECT * FROM _tempTable2 , and then output this. I was thinking of implementing a third stored procedure which does this but I am not sure whether this is the right thing to do? Much appreciated help:)

I have a table connected to my ASP.NET MVC application, and I have created two stored procedures in SQL Server. Is it possible to implement these stored procedures in a way so that when the table is output, it can be grouped into these stored procedures?

MetBasicCriteria

ALTER PROCEDURE [dbo].[MetBasicCriteria]
    -- Add the parameters for the stored procedure here
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    SELECT * 
    FROM dbo.Applications
    WHERE NorwegianCitizen=1 
    AND CurrentlyInUni=1
    AND Norwegian=1
    AND English=1
END

MetMoreCriteria

ALTER PROCEDURE [dbo].[MetMoreCriteria] 
    -- Add the parameters for the stored procedure here
    
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    --EXEC [dbo.MetBasicCriteria]

    SELECT * 
    FROM dbo.Applications
    WHERE (Dutch=1
    OR OtherCitizenships='Dutch'
    OR (Course_bachelor='Political Science' OR Course_bachelor='Economy' OR Course_bachelor='International Relations')
    OR (Grade_Bachelor='a' OR Grade_Bachelor='A' OR Grade_Bachelor='b' OR Grade_Bachelor='B'))
    --AND MetBasicCriteria=1
END

In other words --> can I use say 3 different stored procedures, save the outcomes of these 3 into different temporary tables, and the using UNION ALL combine them into 1 temporary table?

Thanks in advance

Answer 1

I just take your second procedure code and modify it as a simple POC. I have no idea how you intend to merge or alter or combine the resultsets from your first procedure with that of your second procedure. So I leave that for you. I will also remove the meaningless comments you leave in the code since you seem to be using some sort of template.

ALTER PROCEDURE [dbo].[MetMoreCriteria] 
AS
BEGIN
    SET NOCOUNT ON;

    create table #basic (
       id  int not null,
       ...
    );
    Insert #basic (id) --column list to be defined
    EXEC [dbo.MetBasicCriteria];

    SELECT appl.id, ...  
    FROM dbo.Applications as appl
    WHERE (appl.Dutch=1
       OR appl.OtherCitizenships='Dutch'
       OR (appl.Course_bachelor in ('Political Science', 'Economy', 'International Relations'))
       OR (appl.Grade_Bachelor in ('A', 'a', 'B', 'b'))
       )
    AND EXISTS (SELECT * FROM #basic as basic where basic.id = appl.id)
    ORDER BY ...;
END

Hopefully I used the parentheses correctly but I can't test it and this edit widget does not auto-count or correct typos or mistakes. Some better coding points:

• define an alias for each table and use it for every column reference.
• don't use "*" generally as a column list
• Using IN rather than a series of logical OR comparisons makes your code more readable and less prone to error

The column list in the SELECT and INSERT statements should be specific - don't use the lazy asterisk to select all columns since you typically don't need them all. If you do need them all, then specify each column to avoid future problems if the schema of the tables changes. The only place where "*" is acceptable as a column list is inside an EXISTS clause.

I also added the ORDER BY clause since the consumer of a resultset usually wants those rows ordered. But perhaps your application/consumer does not care? If so, remove it and save some processor cycles.

Lastly this is just one approach. You could also make your first procedure a view or a UDF since it does nothing complicated. And that comment can also apply to this procedure. Perhaps you are just over-complicating a rather simple set of logic? NB that I omit any error-handling and leave that to you. And let me re-iterate that this is NOT a recommendation. Simply one implementation option.