D426 Data Management Foundations - Set 4 - Part 3

Correct Answer: A function that performs calculations on a set of values

Aggregate functions perform calculations on a set of values and return a single summary value, such as SUM(), AVG(), COUNT(), etc.

Correct Answer: HAVING

The HAVING clause is used to filter groups of records after the aggregation has been performed.

Correct Answer: LIMIT

The LIMIT clause restricts the number of rows returned in the result set of a SQL query.

Correct Answer: CURTIME()

The CURTIME() function returns the current time from the system clock in SQL.

Correct Answer: Undoes changes made in the current transaction

The ROLLBACK command is used to undo any changes made during the current transaction, reverting the database to its previous state.

Correct Answer: ALTER DATABASE

The ALTER DATABASE statement is used to modify database properties, including changing the default character set.

Correct Answer: To structure the organization of data

A schema defines the organization of data, including how tables and relationships are structured in the database.

Correct Answer: COUNT()

The COUNT() function is used to determine the total number of rows in a specific column, including those that may contain NULL values.

Correct Answer: ALTER TABLE MODIFY COLUMN

The ALTER TABLE statement with MODIFY COLUMN is used to change the data type of an existing column in SQL.

Correct Answer: UNION

The UNION clause combines the result sets of two or more SELECT statements into a single result set, eliminating duplicates.