# Templates and regular expressions

Use regexp when an input line can be described by capture groups. Use template when the input or output follows explicit literal separators and field escaping rules.

## Read with a regular expression

Declare destination columns in capture order and set regexp_pattern on the INSERT. `regexp_skip_unmatched` controls whether a nonmatching line can be skipped.

The regexp input format is line-based. Pattern matching and field conversion are separate: a captured string must still satisfy its target column type.

## Write a template

`template_row` describes field positions and escaping. This example writes two raw fields separated by a vertical bar:

```sql
SELECT 7 AS id, 'Ada' AS name
SETTINGS template_row = '${0:Raw}|${1:Raw}'
FORMAT template;
```

```text
7|Ada
```

There is no trailing newline. `template_row_separator` separates rows only; the template's literal bytes determine the rest of the output.

## Input matching

Template input must match its literal separators. Choose escaping rules that distinguish field content from those separators. All options are statement-scoped.

See [regexp](https://coordinatordb.com/docs/reference/formats/regexp) and [template](https://coordinatordb.com/docs/reference/formats/template/template) for complete input syntax and settings.