Returns the keys of a JSON object — one row per key.
JSONB_OBJECT_KEYS(<json object>)
Only the names of top-level keys, without values. Handy for finding out which fields actually occur in a JSON column, or checking that nothing extra has turned up.
employees
| name | department | salary | bonus | phone |
|---|---|---|---|---|
| Emma | backend | 1200 | 300 | +44 7700 900123 |
| Liam | backend | 1000 | NULL | NULL |
| Olivia | frontend | 1350 | 150 | +44 7700 900456 |
| Noah | frontend | 950 | NULL | +44 7700 900789 |
| Sophia | design | 1200 | 200 | NULL |
These tables already exist in the sandbox — the examples below use them. Want to try this in your own database? Copy the SQL.
| key |
|---|
| color |
| storage |
| wireless |
| key_count |
|---|
| 3 |
| column_name |
|---|
| name |
| bonus |
| phone |
| salary |
| department |
TO_JSONB(e) turns a table row into an object, and JSONB_OBJECT_KEYS lists its keys — that is, the column names.
Top level only: the keys of nested objects aren't included.
For an array — the error cannot call jsonb_object_keys on an array.
The keys don't come in the order they were written: jsonb stores them ordered, shorter ones first.
To check a single key, the ? operator is simpler: data ? 'color' gives true or false.