ClickHouse/docs/zh/sql-reference/table-functions/format.md

slug	sidebar_position	sidebar_label
/zh/sql-reference/table-functions/format	56	format

format

Extracts table structure from data and parses it according to specified input format.

Syntax

format(format_name, data)

Parameters

• format_name — The format of the data.
• data — String literal or constant expression that returns a string containing data in specified format

Returned value

A table with data parsed from data argument according specified format and extracted schema.

Examples

Query:

:) select * from format(JSONEachRow,
$$
{"a": "Hello", "b": 111}
{"a": "World", "b": 123}
{"a": "Hello", "b": 112}
{"a": "World", "b": 124}
$$)

Result:

┌───b─┬─a─────┐
│ 111 │ Hello │
│ 123 │ World │
│ 112 │ Hello │
│ 124 │ World │
└─────┴───────┘

Query:

:) desc format(JSONEachRow,
$$
{"a": "Hello", "b": 111}
{"a": "World", "b": 123}
{"a": "Hello", "b": 112}
{"a": "World", "b": 124}
$$)

Result:

┌─name─┬─type──────────────┬─default_type─┬─default_expression─┬─comment─┬─codec_expression─┬─ttl_expression─┐
│ b    │ Nullable(Float64) │              │                    │         │                  │                │
│ a    │ Nullable(String)  │              │                    │         │                  │                │
└──────┴───────────────────┴──────────────┴────────────────────┴─────────┴──────────────────┴────────────────┘

See Also

• Formats