Filemaker Pro 9 (56)

Question 1

This set entered on 5-12-2014
5.2.14.3

1. p 322. JOIN TABLES (CONT’D). Think of JOIN TABLES this way: INVOICES and PAYMENTS both have a ONE TO MANY RELATIONSHIP to the JOIN TABLE. So ONE INVOICE can connect to MANY JOIN RECORDS, each of which connects to ONE PAYMENT. Likewise, ONE PAYMENT can:

Answer 1

connect to MANY JOIN RECORDS, each of which connects to ONE INVOICE. So YOU GET MANY RELATED records in BOTH DIRECTIONS.

Question 2

2. A JOIN TABLE ALWAYS contains:

Answer 2

TWO FOREIGN KEYS, one from EACH TABLE it is JOINING.

Question 3

3. If your database has MANY TO MANY RELATIONSHIPS, you may have to create a JOIN TABLE to hold just THE TWO FOREIGN KEYS, unless:

Answer 3

your database already has a REAL TABLE that can act as a JOIN TABLE.

Question 4

4. What is an example of a REAL TABLE that can act as a JOIN TABLE?

Answer 4

Your database tracks ORDERS for the PRODUCTS YOU SELL. You have a PRODUCTS TABLE (PRIMARY KEY: PRODUCT SKU FIELD) and an ORDERS TABLE (PRIMARY KEY: ORDER NUMBER FIELD).

Question 5

5. The JOIN TABLE for the PRODUCTS-ORDERS MANY TO MANY RELATIONSHIP is the :

Answer 5

LINE ITEMS TABLE.

Question 6

6. The LINE ITEMS (JOIN TABLE) in the PRODUCTS-ORDERS MANY TO MANY RELATIONSHIP holds what fields?

Answer 6

it holds the PRODUCT SKU (FOREIGN KEY), the ORDER NUMBER (FOREIGN KEY), plus other quantitative fields, such as QUANTITY, PRICE, EXTENDED PRICE, etc.

Question 7

7. Other than being the JOIN TABLE with the FOREIGN FIELDS, the LINE ITEMS TABLE also shows:

Answer 7

a. Which PRODUCTS were on each order
b. How many
c. At what price.

Question 8

8. So the LINE ITEM TABLE not only serves as a JOIN TABLE, but it also:

Answer 8

holds the LINE ITEMS, which are REAL ENTITIES.

Question 9

9. So, how did you ELIMINATE the MANY TO MANY RELATIONSHIPS?

Answer 9

by CREATING JOIN TABLES, so that instead of a MANY TO MANY RELATIONSHIP, you have TWO ‘ONE TO MANY’ RELATIONSHIPS.