Count Salary Categories
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Description
You are given an Accounts table containing account IDs and their income. Classify each account into one of three salary categories: - 'Low Salary': income strictly less than 20000 - 'Average Salary': income between 20000 and 50000 inclusive - 'High Salary': income strictly greater than 50000 Write a SQL query to report the number of accounts in each category. If a category has no accounts, report 0. Return all three categories in the result - even if their count is zero.
Database Schema
Accounts
| Column Name | Example Value |
|---|---|
| account_id | 3 |
| income | 108939 |
Example
Accounts
| account_id | income |
|---|---|
| 3 | 108939 |
| 2 | 12747 |
| 8 | 87709 |
| 6 | 91796 |
Output
| category | accounts_count |
|---|---|
| Low Salary | 1 |
| Average Salary | 0 |
| High Salary | 3 |
Explanation:
Account 2 earns 12747 → Low Salary. Accounts 3, 6, 8 earn above 50000 → High Salary. No account falls in Average Salary range.
Approach hint
Start with a simple approach, explain the trade-off, then move toward a cleaner or more scalable solution.
Common mistake
Skipping assumptions, edge cases, or trade-offs can make an otherwise good answer feel incomplete.
Accounts
| account_id | income |
|---|---|
| 3 | 108939 |
| 2 | 12747 |
| 8 | 87709 |
| 6 | 91796 |
Output
| category | accounts_count |
|---|---|
| Low Salary | 1 |
| Average Salary | 0 |
| High Salary | 3 |