Databases & SQL worksheet with answers

What does WHERE country IN ('NL', 'BE', 'DE') do?

1. AKeeps rows whose country is not in the list
2. BKeeps rows whose country equals any value in the list
3. CKeeps rows whose country value contains all three codes at once
4. DSorts rows in the order of the list

How do you sort a result from the highest to the lowest salary?

1. AORDER BY salary ASC
2. BGROUP BY salary DESC
3. CORDER BY salary DESC
4. DSORT salary DOWN

GRANT and REVOKE belong to which part of SQL?

1. AData Definition Language (DDL)
2. BData Manipulation Language (DML)
3. CData Control Language (DCL)
4. DData Query Language (DQL)

First normal form (1NF) requires that:

1. AThere are no foreign keys
2. BEach column contains atomic values and there are no repeating groups
3. CEvery table has exactly one column
4. DEvery non-key column depends on the whole key and on nothing but the key

What does GRANT SELECT ON employees TO alice do?

1. AAllows the user alice to read the employees table
2. BMakes alice the owner of the database
3. CCopies the employees table to alice
4. DAllows alice to update and delete rows in the employees table

Which statement removes all rows of a table, keeps its structure and cannot take a WHERE clause?

1. ADROP TABLE
2. BTRUNCATE TABLE
3. CALTER TABLE
4. DDELETE FROM with a WHERE clause

Two transactions both read stock = 10, each subtracts 1 and writes the result, giving 9 instead of 8. Which anomaly is this?

1. ADirty read
2. BLost update
3. CPhantom read
4. DDeletion anomaly

Which window function assigns 1, 2, 3, ... to rows within each partition without ties?

1. ADENSE_RANK()
2. BRANK()
3. CCOUNT()
4. DROW_NUMBER()