RETURN and RETURN NEXT in PostgreSQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the RETURN statement do in a PostgreSQL function?

The RETURN statement immediately ends the function and sends back a single value or result to the caller.

beginner

What is the purpose of RETURN NEXT in PostgreSQL functions?

RETURN NEXT adds a row to the result set of a set-returning function without ending the function, allowing multiple rows to be returned one by one.

intermediate

How do RETURN and RETURN NEXT differ in their effect inside a PostgreSQL function?

RETURN ends the function and returns a single result immediately, while RETURN NEXT adds a row to the output and lets the function continue to add more rows.

beginner

In what kind of PostgreSQL function would you use RETURN NEXT?

You use RETURN NEXT in functions declared to return SETOF some type, meaning they return multiple rows instead of just one.

intermediate

What happens if you use RETURN inside a set-returning function before RETURN NEXT?

Using RETURN will immediately stop the function and return the current result, so any rows after RETURN NEXT will not be returned.

Which statement immediately ends a PostgreSQL function and returns a value?

A YIELD

B RETURN NEXT

C RETURN

D CONTINUE

RETURN immediately ends the function and returns a value to the caller.

What does RETURN NEXT do in a PostgreSQL function?

A Adds a row to the result set and continues the function

B Ends the function and returns a single value

C Skips the current iteration

D Resets the function state

RETURN NEXT adds a row to the output and lets the function continue to add more rows.

In which type of function is RETURN NEXT typically used?

A Functions returning a single scalar value

B Functions returning SETOF rows

C Trigger functions

D Aggregate functions

RETURN NEXT is used in functions that return SETOF rows, meaning multiple rows.

What happens if RETURN is used before RETURN NEXT in a set-returning function?

A The function stops and returns immediately

B The function continues normally

C An error is thrown

D RETURN NEXT is ignored but function continues

RETURN stops the function immediately, so any following RETURN NEXT statements are not executed.

Which statement would you use to return multiple rows one by one in a PostgreSQL function?

A RETURN

B RAISE

C EXECUTE

D RETURN NEXT

RETURN NEXT is used to return multiple rows one at a time in set-returning functions.

Explain the difference between RETURN and RETURN NEXT in PostgreSQL functions.

Think about when the function stops and how many rows are returned.

Describe a scenario where you would use RETURN NEXT in a PostgreSQL function.

Consider functions that return lists or sets of data.