The contents of the parent and child tables are:

The child table has the parent_id column that has a foreign key constraint to the id column of the parent table with
ON DELETE CASCADE clause.
Consider the command WHERE id =1;
What is the effect of the above command?

• A. It deletes one row from the parent table and two rows from the child table.
• B. It deletes one row from the parent table and sets the parent _id column to NULL in the child.
• C. It deletes one row from the parent table but does not affect the child table.
• D. It does not delete anything from any table but returns an error.

These there tables represent a many -to-many relationship in asocial networking database:

This query draft is constructed to report for the past 30 days:
Which change will correct this query?

• A. Option A
• B. Option C
• C. Option B
• D. Option D

A table (t1) contains 1000 random integer values in the first column (col1). The random values range from 1 to 1000.
You execute this query:
SELECT col1 FROM t1 WHERE col1< 100
UNION
SELECT col1 FROM t1 WHERE col1 BETWEEN 100 and 200
UNION ALL
SELECT col1 FROM t1 WHERE col 1 >=900
What is the output?

• A. An error, because mixing UNION and UNION ALL in the same query is not permitted
• B. A list of unique values within the ranges of 1-200 and 900-1000
• C. A list of unique values within the range of 1-200 and a list of all values, including duplicates, on the table within the
  range of 900-1000
• D. A list of all values, including duplicates, in the ranges of 1-200 and 900-1000
• E. A list of all values , including duplicates, in the range of 1-200 and a list of unique values in the range of 900-1000

You have two tables: news_source and news_feed.

Here is some sample data from the news _feed table:

• A. Option A
• B. Option C
• C. Option B
• D. Option D