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Problem #2

Infant. Stuffed Animal. Aubrey. s1. has-as-favorite. s2. Brooks. Robby. Min. Max. Min. Max. An infant can choose only one favorite stuffed animal.

Patman
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Problem #2

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  1. Infant Stuffed Animal Aubrey s1 has-as-favorite s2 Brooks Robby Min Max Min Max • An infant can choose only one favorite stuffed animal. •  The same stuffed animal can be chosen as favorite by more than one infant. For example, both Aubrey and Brooks have chosen the same stuffed animal (s1) as their favorite. • No infant has chosen s2 as favorite stuffed animal. • Robby has not chosen a favorite stuffed animal yet. Group _______ Group _______ Problem #1 Problem #2 Problem #2

  2. Infant Stuffed Animal Aubrey s1 has-as-favorite s2 Brooks Robby 0 1 0 N Min Max Min Max • An infant can choose only one favorite stuffed animal. •  The same stuffed animal can be chosen as favorite by more than one infant. For example, both Aubrey and Brooks have chosen the same stuffed animal (s1) as their favorite. • No infant has chosen s2 as favorite stuffed animal. • Robby has not chosen a favorite stuffed animal yet. Group _______ Problem #1 -- Solution Problem #2 Problem #2

  3. Parent Child Min Max Min Max Group _______ Problem #2

  4. 1. Being a parent implies that you have one or more children. 2. All children have 2 parents. Parent Child Group _______ Problem #2

  5. Being a parent implies that you have one or more children. • 2. All children have 2 parents. Parent Child 1 N 1 N Min Max Min Max Problem #2 -- Solution

  6. Here are our payment policies: • Customers must pay no later than 60 days after shipment. • We allow installments. • All cash receipts come from sales; i.e. we need to record a sale/shipment for each cash receipt. • The same cash receipt can pay for multiple sales/shipments. Sale/ Shipment Cash Receipt Min Max Min Max Group _______ Group _______ Problem #5 Problem #3

  7. Here are our payment policies: • Customers must pay no later than 60 days after shipment. • We allow installments. • All cash receipts come from sales; i.e. we need to record a sale/shipment for each cash receipt. • The same cash receipt can pay for multiple sales/shipments. Sale/ Shipment Cash Receipt 0 N 1 N Min Max Min Max Group _______ Problem #5 Problem #3 -- Solution

  8. Customers either order from us using the Internet (our Website) or pick up goods from our store (there is no order). A sale occurs when (1) we ship the goods, or (2) a customers picks up goods from our store. For orders placed through our website, it usually takes us 48 hours to ship the goods to the customers (and thus to fulfill the order). We often use partial shipments – we ship what we have now and then ship the rest of the order later (when it becomes available). There is no order when customers pick up goods from our store (a sale). To save money, we try to execute (fulfill) multiple orders with one shipment. Order Sale/Shipment Delivery Min Max Min Max Group _______ Problem #4

  9. Customers either order from us using the Internet (our Website) or pick up goods from our store (there is no order). A sale occurs when (1) we ship the goods, or (2) a customers picks up goods from our store. For orders placed through our website, it usually takes us 48 hours to ship the goods to the customers (and thus to fulfill the order). We often use partial shipments – we ship what we have now and then ship the rest of the order later (when it becomes available). There is no order when customers pick up goods from our store (a sale). To save money, we try to execute (fulfill) multiple orders with one shipment. Order Sale/Shipment 0 N 0 N Delivery Min Max Min Max Problem #4 -- Solution

  10. Monica owes a store that sells stuffed animals. She records all her customers and items (stuffed animals) in a database. She currently has more than 350 customers; all of them are recorded in the database. She currently sells 486 different items; all of them are recorded in the database. Further, for her 25 most important customers (“Club 25”) she keeps a list of their 5 favorite items. She uses that information to send gifts (birthday, wedding, etc.). An item can be the favorite item for more than one “Club 25” member. Club 25 Customer Item Min Max Min Max Group _______ Problem #5

  11. Monica has a store that sells stuffed animals. She records all her customers and items (stuffed animals) in a database. She currently has more than 350 customers; all of them are recorded in the database. She currently sells 486 different items; all of them are recorded in the database. Further, for her 25 most important customers (“Club 25”) she keeps a list of their 5 favorite items. She uses that information to send gifts (birthday, wedding, etc.). An item can be the favorite item for more than one “Club 25” member. Club 25 Customer Item 0 N 0 N Min Max Min Max Group _______ Problem #5 – Solution

  12. UD organizes 10 “emerging issues” seminars each semester. Students are required to attend at least three of the seminars. Enrollment is limited to thirty students per seminar. For seminars that are full, students can put themselves on a waiting list. • The IFRS seminar is full; i.e., thirty students are enrolled. • We received our first enrollment thirty minutes after we opened the (IFRS) seminar for enrolment (and thus thirty minutes after we recorded the seminar in the database). • Actually, we have already five students on the waiting list for this seminar. • The “Continuous Auditing” seminar is less popular. We have only fifteen enrollments thus far. Obviously, nobody is currently on the waiting list for the “Continuous Auditing” seminar. • One of our students, Jimmy Hunton, is enrolled in all ten seminars! However, Julie Dunn, another student, is on the waiting list of two seminars (including the IFRS one), but is not enrolled in any seminar yet. Still better than Graham Gerard who has not enrolled for any of the seminars and is not on any waiting list. He is in big trouble! MAX MAX MIN MIN enrolled_in STUDENT SEMINAR on_the_waiting_list_of MIN MIN MAX MAX Define the cardinalities Group _______ Problem #8 Group _______ Problem #6

  13. UD organizes 10 “emerging issues” seminars each semester. Students are required to attend at least three of the seminars. Enrollment is limited to thirty students per seminar. For seminars that are full, students can put themselves on a waiting list. • The IFRS seminar is full; i.e., thirty students are enrolled. • We received our first enrollment thirty minutes after we opened the (IFRS) seminar for enrolment (and thus thirty minutes after we recorded the seminar in the database). • Actually, we have already five students on the waiting list for this seminar. • The “Continuous Auditing” seminar is less popular. We have only fifteen enrollments thus far. Obviously, nobody is currently on the waiting list for the “Continuous Auditing” seminar. • One of our students, Jimmy Hunton, is enrolled in all ten seminars! However, Julie Dunn, another student, is on the waiting list of two seminars (including the IFRS one), but is not enrolled in any seminar yet. Still better than Graham Gerard who has not enrolled for any of the seminars and is not on any waiting list. He is in big trouble! N N MAX MAX 0 0 MIN MIN enrolled_in STUDENT SEMINAR on_the_waiting_list_of 0 0 MIN MIN N N MAX MAX Define the cardinalities Group _______ Problem #8 Problem #6 -- Solution

  14. This year, the NBA hands out their first “MVP-P” award –only NBA players can vote for this award. All NBA players are asked to mail their vote by May 1st. Players don’t have to vote. The rules are simple: (1) you can’t vote for yourself, and (2) you can vote for one player only. The player with the most votes will be given the award. Obviously, only a select group of players will receive votes; i.e., many players will receive zero (0) votes. Note – we need to record all NBA players in our database even when they don’t vote. (NBA) Player Min Min Max Max votes_for received_vote_from Group _______ Problem #7

  15. This year, the NBA hands out their first “MVP-P” award –only NBA players can vote for this award. All NBA players are asked to mail their vote by May 1st. Players don’t have to vote. The rules are simple: (1) you can’t vote for yourself, and (2) you can vote for one player only. The player with the most votes will be given the award. Obviously, only a select group of players will receive votes; i.e., many players will receive zero (0) votes. Note – we need to record all NBA players in our database even when they don’t vote. (NBA) Player Min 0 0 Min Max 1 N Max votes_for received_vote_from Problem #7 -- Solution

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