SQL Server Team-based Development - Red Gate Software

Chapter 6: Reusing T-SQL Code
Use constraints where possible
In many cases, constraints are the easiest and simplest to use. To demonstrate this point,
consider the Teams table shown in Listing 6-25, with a primary key constraint on the
TeamID column.
CREATE TABLE dbo.Teams
(
TeamID INT NOT NULL ,
Name VARCHAR(50) NOT NULL ,
CONSTRAINT PK_Teams PRIMARY KEY ( TeamID )
) ;
Listing 6-25: Creating the Teams table.
Since we wish to forbid access to the base tables, teams will be inserted into the table, one
at a time, by calling a stored procedure. Our business rule is simple: team names must be
unique. So, we need to decide where to implement this business rule. One choice is to
enforce it in the stored procedure, as shown in Listing 6-27.
CREATE PROCEDURE dbo.InsertTeam
@TeamID INT ,
@Name VARCHAR(50)
AS
BEGIN ;
-- This is not a fully-functional stored
-- procedure. Error handling is skipped to keep
-- the example short.
-- Also potential race conditions
-- are not considered in this simple module
INSERT INTO dbo.Teams
( TeamID ,
Name
)
SELECT @TeamID ,
@Name
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