CASE Expressions in SQL

From the SQL cheat sheet · CASE & NULL Handling · verified Jul 2026

CASE Expressions

Add conditional logic (if/else) to queries.

sql

-- CASE WHEN
SELECT name,
  CASE
    WHEN age < 18 THEN 'Minor'
    WHEN age < 65 THEN 'Adult'
    ELSE 'Senior'
  END AS age_group
FROM users;

-- Simple CASE
SELECT name,
  CASE status
    WHEN 'A' THEN 'Active'
    WHEN 'I' THEN 'Inactive'
    ELSE 'Unknown'
  END AS status_label
FROM users;

💡 CASE works everywhere: SELECT, WHERE, ORDER BY, UPDATE, and even inside aggregates

⚡ Use CASE inside COUNT/SUM for pivot-style crosstab reports

📌 CASE evaluates conditions in order — the first match wins, then it stops

🟢 Always include ELSE to handle unexpected values — otherwise you get NULL

caseconditionalwhen-then

More SQL tasks

NULL Handling

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