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Case Study: 1
Scenario 1
Application Information
Your company receives invoices in XML format from customers. Currently, the invoices are
stored as files and processed by a desktop application. The application has several
performance and security issues. The application is being migrated to a SQL Server-based
solution. A schema named InvoiceSchema has been created for the invoices xml.
The data in the invoices is sometimes incomplete. The incomplete data must be stored and
processed as-is. Users cannot filter the data provided through views.
You are designing a SQL Server database named DB1 that will be used to receive, process,
and securely store the invoice data. A third-party Microsoft .NET Framework component will
be purchased to perform tax calculations. The third-party tax component will be provided as a
DLL file named Treytax.dll and a source code file named Amortize.cs. The component will
expose a class named TreyResearch and a method named Amortize(). The files are located in
c:\temp\.
The following graphic shows the planned tables:
You have a sequence named Accounting.InvoiceID_Seq.
You plan to create two certificates named CERT1 and CERT2. You will create CERT1 in
master. You will create CERT2 in DB1.
You have a legacy application that requires the ability to generate dynamic T-SQL statements
against DB1. A sample of the queries generated by the legacy application appears in
Legacy.sql.
Application Requirements
The planned database has the following requirements:
• All stored procedures must be signed.
• The original XML invoices must be stored in the database.
• An XML schema must be used to validate the invoice data.
• Dynamic T-SQL statements must be converted to stored procedures.
• Access to the .NET Framework tax components must be available to T-SQL objects.
• Columns must be defined by using data types that minimize the amount of space used
by each table.
• Invoices stored in the InvoiceStatus table must refer to an invoice by the same
identifier used by the Invoice table.
• To protect against the theft of backup disks, invoice data must be protected by using
the highest level of encryption.
• The solution must provide a table-valued function that provides users with the ability
to filter invoices by customer.
• Indexes must be optimized periodically based on their fragmentation by using the
minimum amount of administrative effort.
Usp_InsertInvoices.sql
Invoices.xml
All customer IDs are 11 digits. The first three digits of a customer ID represent the customer’s
country. The remaining eight digits are the customer’s account number.
The following is a sample of a customer invoice in XML format:
InvoicesByCustomer.sql
Legacy.sql
CountryFromID.sql
IndexManagement.sql
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You need to create a function that filters invoices by CustomerID. The SELECT statement
for the function is contained in InvoicesByCustomer.sql.
Which code segment should you use to complete the function?
A.
Option A
B.
Option B
C.
Option C
D.
Option D
that the difference between A and D ?
Nothing, and I’d go with B anyway
I think B should be right answer
No correct answers:
A. and D. the same: no @TblInvoices insertion, no RETURN
B. No RETURN
C. Must be: RETURN TABLE AS RETURN
CREATE FUNCTION Accounting.fn_InvoicesByCustomer(@CustID varchar(11))
RETURNS @TblInvoices TABLE
(CustomerID bigint, CustomerName nvarchar(255),
InvoiceID bigint, InvoiceDate date,
Total decimal(8,2), PONumber bigint
)
AS
BEGIN
INSERT INTO @TblInvoices
SELECT CustomerID,
CustomerName,
InvoiceID, InvoiceDate, Total, PONumber
FROM Accounting.Invoices
WHERE CustomerID=@CustID
RETURN
END;
GO
‘C’ is the answer with the fewest errors
In the answers ‘A’, ‘B’, ‘C’ there are Problems with:
– the brackets in the Select-Statement
– the missing begin / end
– the missing return
– leading zeros in the customerID (Invoices.xml Line 03)
I think there is a little error in the answer ‘C’
Replacing ‘xml’ with ‘table’ you get:
CREATE FUNCTION Accounting.fn_InvoicesByCustomer(@CustID varchar(11))
RETURNS TABLE
AS
(SELECT CustomerID,
CustomerName,
InvoiceID,
InvoiceDate,
Total,
PONumber
FROM Accounting.Invoices
WHERE CustomerID=@CustID);