Primary and Foreign Keys — Learn free

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Questions 1–10 of 10

1. What are the usual short names for Primary Key and Foreign Key?
Question 1A. PK1 and FK1B. Pkey and FkeyC. Main and LinkD. Index and PointerE. Head and Tail
2. Why are primary and foreign keys so important in a database?
Question 2A. They make tables load fasterB. A proper data model cannot be created without themC. They replace the need for tablesD. They encrypt the dataE. They are required by law
3. What problem did repeating "United States of America" in the Family table illustrate?
Question 3A. Spelling errorsB. Wasted space from storing a long value many timesC. Missing rowsD. Too few columnsE. Slow network access
4. After the change, what does the Family table store in the Birth Location column?
Question 4A. The full country nameB. A country code such as 001C. A map imageD. The member's date of birthE. Nothing — the column is removed
5. In the Family and Birth_Location tables example, which column is declared the PRIMARY key?
Question 5A. Location_ID in the Family tableB. ID in the Birth_Location tableC. Name in the Family tableD. Date of Birth in the Family tableE. Country name in Birth_Location
6. And which column is declared the FOREIGN key?
Question 6A. ID in Birth_LocationB. Location_ID in FamilyC. Name in FamilyD. Relationship in FamilyE. Country name in Birth_Location
7. What does declaring the keys make possible?
Question 7A. Joining the two tables to extract the full country namesB. Deleting the Birth_Location tableC. Storing images in the tableD. Sorting rows by colourE. Running the database without a server
8. How do you find which country the code "001" refers to?
Question 8A. By guessingB. By joining Family to Birth_Location on the key columnsC. By deleting the codeD. By asking the grandfatherE. By storing the name in every row again
9. A primary key value in a table should be:
Question 9A. Repeated in several rowsB. Unique for each rowC. Left empty when unknownD. The same as the table nameE. A long descriptive text
10. Which sentence best describes a foreign key?
Question 10A. A column that stores a value from another table's primary key to link the twoB. A column that must be the first in a tableC. A key from a foreign countryD. A column that cannot be joinedE. A duplicate of the primary key in the same table