$1.$ Create an ER diagram for a hardware store. Make sure you cover $($at least$)$ store transactions, inventory, and personnel. Base your ER diagram on an appropriate set of business rules that you develop. $($Note: It would be useful to visit a hardware store and conduct interviews to discover the type and extent of the store$$s operations.$)$

$2)$ Use the following brief description of operations as the source for the next database design.

All aircraft owned by ROBCOR require periodic maintenance. When maintenance is required, a maintenance log form is used to enter the aircraft$$s identification number, the general nature of the maintenance, and the maintenance starting date. A sample maintenance log form is shown in Figure PB$\mathrm{.}7$A$.$

Note that the maintenance log form contains a space used to enter the aircraft release date and a signature space for the supervising mechanic who releases the aircraft into service. Each maintenance log form is numbered sequentially. Note: A supervising mechanic is one who holds a special Federal Aviation Administration $($FAA$)$ Inspection Authorization $($IA$).$ Three of ROBCOR$$s ten mechanics hold such an IA$.$

Once the maintenance log form is initiated, the maintenance log form$$s number is written on a maintenance specifica$-$ tion sheet, also known as a maintenance line form. When completed, the specification sheet contains the details of each maintenance action, the time required to complete the maintenance, parts $($if any$)$ used in the maintenance action, and the identification of the mechanic who performed the maintenance action. The maintenance specification sheet is the billing source $($time and parts for each of the maintenance actions$),$ and it is one of the sources through which parts use may be audited. A sample maintenance specification sheet $($line form$)$ is shown in Figure PB$\mathrm{.}7$B$.$

Parts used in any maintenance action must be signed out by the mechanic who used them, thus allowing ROBCOR to track its parts inventory. Each sign$-$out form contains a listing of all parts associated with a given maintenance log entry. Therefore, a parts sign$-$out form contains the maintenance log number against which the parts are charged. In addition, the parts sign$-$out procedure is used to update the ROBCOR parts inventory. A sample parts sign$-$out form is shown in Figure PB$\mathrm{.}7$C$.$

Mechanics are highly specialized ROBCOR employees, and their qualifications are quite different from those of an accountant or a secretary$,$ for example.

Given this brief description of operations and using the Chen ER methodology, draw the fully labeled ER diagram. Make sure you include all appropriate relationships, connectivities, and cardinalities.

$3)$ You have just been employed by the ROBCOR Trucking Company to develop a database. To gain a sense of the database$$s intended functions, you spent some time talking to ROBCOR$$s employees and you examined some of the forms used to track driver assignments and truck maintenance. Your notes include the following observations:

$$ Some drivers are qualified to drive more than one type of truck operated by ROBCOR. A driver may, therefore, be assigned to drive more than one truck type during some period of time. ROBCOR operates several trucks of a given type. For example, ROBCOR operates two panel trucks, four half$-$ton pick$-$up trucks, two single$-$axle dump trucks, one double$-$axle truck, and one $16-$wheel truck. A driver with a chauffeur$$s license is qualified to drive only a panel truck and a half$-$ton pick$-$up truck and, thus, may be assigned to drive any one of six trucks. A driver with a commer$-$ cial license with an appropriate heavy equipment endorsement may be assigned to drive any of the $10$ trucks in the ROBCOR fleet. Each time a driver is assigned to drive a truck, an entry is made in a log containing the employee number, the truck identification, and the sign$-$out $($departure$)$ date. Upon the driver$$s return, the log is updated to include the sign$-$in $($return$)$ date and the number of driver duty hours.

$$ If trucks require maintenance, a maintenance log is filled out. The maintenance log includes the date the truck was received by the maintenance crew. The truck cannot be released for service until the maintenance log release date has been entered and the log has been signed off by an inspector.

$$ All inspectors are qualified mechanics, but not all mechanics are qualified inspectors.

$$ Once the maintenance log entry has been made, the maintenance log number is transferred to a service log in which all service log transactions are entered. A single maintenance log entry can give rise to multiple service log entries. For example, a truck might need an oil change as well as a fuel injector replacement, a brake adjustment, and a fender repair.

$$ Each service log entry is signed off by the mechanic who performed the work. To track the maintenance costs for each truck, the service log entries include the parts used and the time spent to install the part or to perform the service. $($Not all service transactions involve parts. For example, adjusting a throttle linkage does not require the use of a part.$)$

All employee are automatically covered by a standard helth insurance policy. however, ROBCOR'S benifits include optional copaid term life insurance and disable insurance. employee can select both options $,$ one option or no option.

Given those brif notes, create the ER diagram. make sure you include all apporopriate entities and relationship define all connectivities and cardinalities.