ClickHouse/docs/en/sql-reference/table-functions/merge.md

---
slug: /en/sql-reference/table-functions/merge
sidebar_position: 38
sidebar_label: merge
---

# merge

Creates a temporary [Merge](../../engines/table-engines/special/merge.md) table. The table structure is taken from the first table encountered that matches the regular expression.

**Syntax**

```sql
merge('db_name', 'tables_regexp')
```
**Arguments**

- `db_name` — Possible values:
    - database name, 
    - constant expression that returns a string with a database name, for example, `currentDatabase()`,
    - `REGEXP(expression)`, where `expression` is a regular expression to match the DB names.

- `tables_regexp` — A regular expression to match the table names in the specified DB or DBs.

**See Also**

- [Merge](../../engines/table-engines/special/merge.md) table engine
Get rid of toc_en.yml (#10023) 2020-04-03 13:23:32 +00:00			`---`
add slugs 2022-08-28 14:53:34 +00:00			`slug: /en/sql-reference/table-functions/merge`
Removed /ja folder, cleaned up /ru markdown 2022-04-09 13:29:05 +00:00			`sidebar_position: 38`
			`sidebar_label: merge`
Get rid of toc_en.yml (#10023) 2020-04-03 13:23:32 +00:00			`---`

Remove H1 anchor tags from docs 2022-06-02 10:55:18 +00:00			`# merge`
Sources for english documentation switched to Markdown. Edit page link is fixed too for both language versions of documentation. 2017-12-28 15:13:23 +00:00
Initial 2021-11-01 10:39:25 +00:00			`Creates a temporary [Merge](../../engines/table-engines/special/merge.md) table. The table structure is taken from the first table encountered that matches the regular expression.`
Sources for english documentation switched to Markdown. Edit page link is fixed too for both language versions of documentation. 2017-12-28 15:13:23 +00:00
Initial 2021-11-01 10:39:25 +00:00			`Syntax`

			```sql
			`merge('db_name', 'tables_regexp')`
			```
			`Arguments`

Possible values for db name 2021-11-02 14:29:20 +00:00			- `db_name` — Possible values:
			`- database name,`
			- constant expression that returns a string with a database name, for example, `currentDatabase()`,
			- `REGEXP(expression)`, where `expression` is a regular expression to match the DB names.
Initial 2021-11-01 10:39:25 +00:00
			- `tables_regexp` — A regular expression to match the table names in the specified DB or DBs.

			`See Also`

Docs: Replace annoying three spaces in enumerations by a single space 2023-04-19 15:55:29 +00:00			`- [Merge](../../engines/table-engines/special/merge.md) table engine`