> ## Documentation Index
> Fetch the complete documentation index at: https://docs.narrative.io/llms.txt
> Use this file to discover all available pages before exploring further.
# UPDATE
> Reference for the UPDATE statement
The `UPDATE` statement modifies existing rows in a dataset. Each `UPDATE` assigns new values to one or more columns, optionally filtered by a `WHERE` clause.
UPDATE runs against datasets you own. To update rows during a materialized view refresh, use the [MERGE ON clause](/guides/nql/incremental-upserts) inside `CREATE MATERIALIZED VIEW` instead.
## Syntax
```sql theme={null}
UPDATE table_reference
SET
column1 = expression1
[, column2 = expression2, ...]
[WHERE condition]
```
* The `SET` clause lists column assignments. The right-hand side of each assignment can be any NQL expression valid for the target column's [data type](/nql/data-types), including references to other columns in the same row.
* The `WHERE` clause is optional. If omitted, **every row in the dataset is updated** — include a `WHERE` clause unless that is the intended behavior.
* The `SET` expressions and the `WHERE` condition can reference only the target dataset. Subqueries that read from another dataset (for example, `WHERE id IN (SELECT id FROM company_data."456")`) are not supported.
## Examples
**Update a single column with a literal:**
```sql theme={null}
UPDATE company_data."123"
SET status = 'archived'
WHERE user_id = 42
```
**Update multiple columns using an expression:**
```sql theme={null}
UPDATE company_data."123"
SET
email = LOWER(email),
last_updated_at = CURRENT_TIMESTAMP
WHERE email IS NOT NULL
```
**Conditional update across many rows:**
```sql theme={null}
UPDATE company_data.pipeline_log
SET status = 'stale'
WHERE
status = 'created'
AND created_at < CURRENT_TIMESTAMP - INTERVAL '30' DAY
```
## Execution context
UPDATE statements can run in two places:
| Execution surface | When to use |
| -------------------------------------------------------------------------------------- | --------------------------------------------------- |
| NQL query endpoint | Ad-hoc updates from an API client or Data Studio |
| [`ExecuteDml` workflow task](/guides/workflows/workflow-orchestration#supported-tasks) | Scheduled or event-driven updates inside a workflow |
Running UPDATE without a `WHERE` clause modifies every row in the target dataset. Review the statement — or run the corresponding `SELECT` with the same predicate first — before executing.
***
## Related content
Add rows to a dataset
Remove rows from a dataset
Update or insert rows during materialized view refresh
Run DML statements from a workflow