$4.$ Answer the following questions based on the given scenario:

Ned$$s Dry Cleaning Case Questions

Ned Smith owns and operates Ned$$s Dry Cleaning, which is an upscale dry cleaner in a well$-$to$-$do suburban neighborhood. Ned makes his business stand out from the competition by providing superior customer service. He wants to keep track of each of his customers and their orders. Ultimately, he wants to notify them that their clothes are ready via email. Suppose that you have designed a database for Ned$$s Dry Cleaning that has the following tables:

Client $($ClientID$,$ FirstName, LastName, Phone$)$

INVOICE $($InvoiceNumber$,$ ClientID$*,$ DateIn, DateOut, Subtotal, Tax, TotalAmount$)$

INVOICE$\_$ITEM $($InvoiceNumber$,$ ItemNumber, ServiceID, Quantity, UnitPrice, ExtendedPrice$)$

SERVICE $($ServiceID$,$ ServiceDescription, UnitPrice$)$

Assume that all relationships have been defined, as implied by the foreign keys in this table list, and that the appropriate referential integrity constraints are in place.

Questions

$1.$ Alter client table by adding a new column $$address$$ for each client.

$2.$ Alter the client table by changing the phone column to $$contact$$ for each client.

$3.$ Create a constraint on unitPrice column of Invoice$\_$Item table. UnitPrice value should be greater than $$20.$

$4.$ Add a computed $$full$\_$name$$ to the Client table by using the ALTER TABLE ADD column.