SQL Table Aliases
A short nickname for a table — barely useful with one table, essential once queries involve more than one.
What & Why
A table alias gives a table a short, temporary nickname for the rest of the query. On a single-table query it just saves typing; once JOINs enter the picture (a later lesson), it becomes essential for telling identically-named columns from different tables apart.
See How It Works
| id | name | channel | spend | start_date | end_date | status | target_segment |
|---|---|---|---|---|---|---|---|
| 1 | Spring Launch | google_ads | 55000.00 | 2024-01-15 | 2024-03-31 | active | smb |
| 2 | Retention Webinar | 45000.00 | 2024-02-10 | 2024-04-15 | active | enterprise | |
| 3 | Finance Retargeting | 50000.00 | 2024-03-12 | 2024-05-31 | active | enterprise | |
| 4 | Enterprise Search | google_ads | 60000.00 | 2024-04-01 | 2024-06-30 | active | enterprise |
EXAMPLE QUERY
SELECT e.name, e.spend
FROM marketing.campaigns e;RESULT — the alias changes query syntax, not output data
| name | spend |
|---|---|
| Spring Launch | 55000.00 |
| Retention Webinar | 45000.00 |
| Finance Retargeting | 50000.00 |
| Enterprise Search | 60000.00 |
The e alias is valid only inside this query; the real table remains marketing.campaigns.
Now You Try
Practice this concept
SaaS leadership wants active account names, industries, and MRR using a short table alias.
Available schema
saasPrefix tables with saas.table_name.
nameindustrymrrsaas.accounts| Column | Type |
|---|---|
| id | integer |
| name | text |
| plan | text |
| mrr | numeric |
| created_at | timestamp with time zone |
| churned_at | timestamp with time zone |
| country | text |
| employee_count | integer |
| industry | text |
| customer_segment_v2 | text |
query.sql
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