CASE WHEN in PostgreSQL - Examples & AI Generator

The CASE WHEN statement in PostgreSQL helps you implement conditional logic inside your SQL queries. Its flexibility allows for dynamic field calculation, but remembering the exact PostgreSQL CASE WHEN syntax—especially when switching from other databases—can be complex and time-intensive. AI2sql lets you skip this manual step. Instantly generate CASE WHEN queries from simple prompts—no coding, no reference checks.

CASE WHEN Syntax in PostgreSQL

Basic Structure

CASE
  WHEN condition THEN result
  [WHEN ...]
  [ELSE alternative_result]
END

• WHEN: Your logical condition.

• THEN: Value returned if the condition is true.

• ELSE (optional): Default value if no conditions match.

• END: Closes the CASE statement.

Note: PostgreSQL follows standard SQL for CASE WHEN, but always test behavior on your version for subtle differences.

CASE WHEN Examples You Can Generate Instantly

• Customer Loyalty Tier Based on Total Orders

SELECT customer_name,
  CASE
    WHEN total_orders >= 100 THEN 'Platinum'
    WHEN total_orders >= 50 THEN 'Gold'
    WHEN total_orders >= 10 THEN 'Silver'
    ELSE 'Bronze'
  END AS loyalty_tier
FROM customers;

• Flagging Large Orders

SELECT order_id, order_amount,
  CASE WHEN order_amount > 1000 THEN 'High Value'
       ELSE 'Regular'
  END AS order_category
FROM orders;

• Product Stock Status

SELECT product_name, quantity_in_stock,
  CASE
    WHEN quantity_in_stock = 0 THEN 'Out of Stock'
    WHEN quantity_in_stock < 10 THEN 'Low Stock'
    ELSE 'In Stock'
  END AS stock_status
FROM products;

Generate CASE WHEN queries in 10 seconds with AI2sql

Why Use AI2sql Instead of Manual CASE WHEN Coding

• Instant output: Generate complex PostgreSQL CASE WHEN queries in 10 seconds.

• No coding required: Just describe what you need in plain English.

• Consistent, correct syntax: No more memorizing or copy-pasting snippets.

• Trusted by over 50,000+ users in 80+ countries across data, development, and engineering roles.

Stop spending time tracking syntax. Try AI2sql Generator or Learn CASE WHEN with more in-depth guides.

Frequently Asked Questions

• Q: Can I use CASE WHEN in the WHERE clause?
  A: While CASE WHEN returns a value and is typically used in SELECT or ORDER BY, it can be used in WHERE to return Boolean results for advanced filtering.

• Q: What is the main difference between CASE WHEN in PostgreSQL vs MySQL?
  A: The core syntax is similar, but PostgreSQL typically prefers the standard SQL format. Always double-check for subtle behavior differences in type casting and NULL handling.

• Q: Does AI2sql support nested CASE WHEN?
  A: Yes. Describe your logic, and AI2sql will generate full nested CASE WHEN statements for PostgreSQL.