Using the information about the database below, write the SQL code to

represent each one of the transactions in questions $23\mathrm{.}1$ to $23\mathrm{.}2.$

Use BEGIN TRANSACTION and COMMIT TRANSACTION to group the SQL

statements in logical transactions.

ABC Markets sell products to customers. The relational diagram shown in Figure

$1$ represents the main entities for ABC$$s database. Note the following important

characteristics:

$$ A customer may make many purchases, each one represented by an invoice.

$$ The CUS$\_$BALANCE is updated with each credit purchase or payment and

represents the amount the customer owes.

$$ The CUS$\_$BALANCE is increased $(+)$ with every credit purchase and decreased

$(-)$ with every customer payment.

$$ The date of last purchase $($CUS$\_$DATELSTPUR$)$ is updated with each new

purchase made by the customer.

$$ The date of last payment $($CUS$\_$DATELSTPMT$)$ is updated with each new

payment made by the customer.

$$ An invoice represents a product purchase by a customer.

$$ An INVOICE can have many invoice LINEs, one for each product purchased.

$$ The INV$\_$TOTAL represents the total cost of invoice including taxes.

$$ The INV$\_$TERMS can be $30,60,$ or $90($representing the number of days

of credit$)$ or $$CASH$,$CHECK$,$ or $$CC$.$

$$ The invoice status can be:

o $$OPEN$$ when an order is placed

o $$PAID$$ when payment for an invoice has been received

o $$CANCEL$$ when an order is placed but is cancelled before payment

is received

$$ A product$$s quantity on hand $($P$\_$QTYOH$)$ is updated $($decreased$)$ with each

product sale.

$$ A customer may make many payments. The payment type $($PMT$\_$TYPE$)$ can

be one of the following:

o $$CASH$$ for cash payments.

o $$CHECK$$ for check payments

o $$CC$$ for credit card payments

$$ The payment details $($PMT$\_$DETAILS$)$ are used to record data about check or

credit card payments:

o The bank, account number, and check number for check payments

o The issuer, credit card number, and expiration date for credit card

payments