SQL Server Team-based Development - Red Gate Software

Chapter 1: Writing Readable SQL
INNER JOIN Person.ContactType ct
ON vc.ContactTypeID = ct.ContactTypeID
WHERE vc.ContactID = @ContactID )
THEN
(SELECT ct.Name FROM
Purchasing.VendorContact vc
INNER JOIN Person.ContactType ct
ON vc.ContactTypeID =
ct.ContactTypeID
WHERE vc.ContactID = @ContactID)
WHEN EXISTS – – Check for store
( SELECT * FROM Sales.StoreContact sc
INNER JOIN Person.ContactType ct
ON sc.ContactTypeID = ct.ContactTypeID
WHERE sc.ContactID = @ContactID )
THEN
(SELECT ct.Name FROM Sales.StoreContact sc
INNER JOIN Person.ContactType ct
ON sc.ContactTypeID =
ct.ContactTypeID
WHERE ContactID = @ContactID)
ELSE NULL
END ;
SET @ContactType
= CASE- – Check for employee
WHEN EXISTS
( SELECT * FROM HumanResources.Employee e
WHERE e.ContactID = @ContactID )
THEN 'Employee'
WHEN EXISTS – – Check for vendor
( SELECT * FROM Purchasing.VendorContact vc
INNER JOIN Person.ContactType ct
ON vc.ContactTypeID = ct.ContactTypeID
WHERE vc.ContactID = @ContactID )
THEN 'Vendor Contact'
WHEN EXISTS – – Check for store
( SELECT * FROM Sales.StoreContact sc
INNER JOIN Person.ContactType ct
ON sc.ContactTypeID = ct.ContactTypeID
WHERE sc.ContactID = @ContactID )
THEN 'Store Contact'
WHEN EXISTS – – Check for individual consumer
( SELECT * FROM Sales.Individual i
WHERE i.ContactID = @ContactID )
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