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Welcome to GlanceSQL
Learn SQL from zero to expert with interactive visuals, clear explanations, and hands-on examples.
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SQL
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🗃️ Example
Result:
🔍 Visual: Filtering Rows
| id | name | dept | salary | city |
|---|---|---|---|---|
Dimmed rows represent data filtered out by WHERE. Only matching rows remain.
🔗 Visual: JOIN
A
Users
A∩B
Matches
B
Orders
🔄 Query Execution Flow
FROM
→
WHERE
→
SELECT
→
ORDER BY
SQL executes logical steps in this order
📊 Visual: GROUP BY Aggregation
Before (raw data)
| dept | salary |
|---|---|
| Engineering | $95,000 |
| Sales | $72,000 |
| Engineering | $110,000 |
| Marketing | $68,000 |
| Sales | $85,000 |
After (GROUP BY)
| dept | avg_salary | count |
|---|---|---|
| Engineering | $102,500 | 2 |
| Marketing | $68,000 | 1 |
| Sales | $78,500 | 2 |
GROUP BY collapses rows with same department into summary rows