ClickHouse/docs/en/sql-reference/statements/describe-table.md

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44	DESCRIBE

DESCRIBE TABLE Statement

DESC|DESCRIBE TABLE [db.]table [INTO OUTFILE filename] [FORMAT format]

Returns the following String type columns:

• name — Column name.
• type— Column type.
• default_type — Clause that is used in default expression (DEFAULT, MATERIALIZED or ALIAS). Column contains an empty string, if the default expression isn’t specified.
• default_expression — Value specified in the DEFAULT clause.
• comment_expression — Comment text.

Nested data structures are output in “expanded” format. Each column is shown separately, with the name after a dot.