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

slug	sidebar_position	sidebar_label
/en/sql-reference/table-functions/merge	130	merge

merge

Creates a temporary Merge table. The table structure is taken from the first table encountered that matches the regular expression.

Syntax

merge(['db_name',] 'tables_regexp')

Arguments

• db_name — Possible values (optional, default is currentDatabase()):

  • 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 table engine