DO blocks for anonymous code in PostgreSQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a DO block in PostgreSQL?

A DO block is a way to run anonymous procedural code in PostgreSQL without creating a stored function. It lets you write and execute code immediately.

beginner

How do you start a DO block in PostgreSQL?

You start a DO block with the keyword DO, followed by $$ to mark the start and end of the code, and specify the language, usually plpgsql.

intermediate

Can you declare variables inside a DO block?

Yes, inside a DO block you can declare variables in the DECLARE section before the BEGIN block, just like in a stored procedure.

beginner

What is the purpose of the BEGIN ... END section in a DO block?

The BEGIN ... END section contains the procedural code that runs when the DO block executes. It groups statements together.

intermediate

Give an example use case for a DO block.

You can use a DO block to perform quick data fixes, run procedural logic, or test code snippets without creating permanent functions.

What keyword starts a DO block in PostgreSQL?

A DO

B BEGIN

C EXECUTE

D RUN

The DO block always starts with the keyword DO.

Which language is commonly used inside a DO block?

A plpgsql

B SQL

C Python

D JavaScript

plpgsql is the procedural language used inside DO blocks in PostgreSQL.

Can you create permanent functions inside a DO block?

A Yes, DO blocks create functions

B Only if you use special syntax

C Yes, but only temporary functions

D No, DO blocks run anonymous code only

DO blocks run anonymous code and do not create permanent functions.

Where do you declare variables inside a DO block?

A Inside the BEGIN ... END section

B Before the DO keyword

C In the DECLARE section before BEGIN

D Variables are not allowed

Variables are declared in the DECLARE section before the BEGIN block.

What delimiter is used to mark the start and end of the code in a DO block?

A '' (single quotes)

B $$

C {}

D "" (double quotes)

The $$ delimiter marks the start and end of the code block in a DO statement.

Explain what a DO block is and how it is used in PostgreSQL.

Think about running quick code without saving it as a function.

Describe the structure of a DO block including variable declaration and code execution sections.

Consider the parts that make up the block from start to finish.