Online Access Free 1Z1-171 Practice Test

What does the INTERSECT operator do in SQL?

• A.Combines all rows from two queries without any conditions
• B.Returns rows from the first query that are not present in the second query
• C.Returns rows that are present in both queries
• D.Combines rows from two queries and includes all duplicates

Which of the following ensures that a relational database enforces data integrity?

• A.Indexes on all columns
• B.Constraints such as primary keys, foreign keys, and unique constraints
• C.Hierarchical data organization
• D.Redundant data storage

What is the purpose of the MERGE statement in SQL?

• A.To delete duplicate rows from a table
• B.To update existing rows or insert new rows in a target table
• C.To combine the results of two queries
• D.To join two tables into one

What is required for the queries combined by a SET operator to work correctly?

• A.The result sets must have the same number of columns and compatible data types.
• B.Both queries must include the WHERE clause.
• C.Both queries must use the GROUP BY clause.
• D.The tables must be joined using a primary key.

What is a SELF JOIN in SQL?

• A.A join of a table with itself
• B.A join that does not require a WHERE clause
• C.A join between tables with identical structures
• D.A join used for Cartesian products