Solution:Step 1: Analyze the CTE definitionThe CTE named 'cte' selects users where active = true, so only active users are included.Step 2: Analyze the main query filteringThe main query selects from 'cte' where id < 5, so it filters active users with id less than 5.Final Answer:All users with ac

[Solved] Given the query:WITH cte AS (SELECT id, name FROM users WHERE active = true) SELECT * FROM cte WHERE id < 5;What will this query return? | PostgreSQL

PostgreSQL - Common Table Expressions

Given the query:

WITH cte AS (SELECT id, name FROM users WHERE active = true) SELECT * FROM cte WHERE id < 5;

What will this query return?

AAll users with id less than 5 regardless of active status

BAll users with active = true and id less than 5

CAll users with active = false and id less than 5

DSyntax error due to incorrect WHERE clause

Step-by-Step Solution

Solution:

Step 1: Analyze the CTE definition
The CTE named 'cte' selects users where active = true, so only active users are included.
Step 2: Analyze the main query filtering
The main query selects from 'cte' where id < 5, so it filters active users with id less than 5.
Final Answer:
All users with active = true and id less than 5 -> Option B
Quick Check:
CTE filters active=true, main query filters id<5 [OK]

Quick Trick: CTE filters first, main query filters second [OK]

Common Mistakes:

Ignoring CTE filter and only applying main WHERE
Assuming all users regardless of active status
Thinking syntax error due to WHERE

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Given the query:

Step 1: Analyze the CTE definition

Step 2: Analyze the main query filtering

Final Answer:

Quick Check:

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