CASE
Syntax
Version 1:
CASE expression
WHEN value_1 THEN result_1
[ WHEN value_2 THEN result_2
... ]
ELSE default_result
END
Version 2:
CASE(
expression,
value_1, result_1,
[ value_2, result_2,
... ]
default_result
)
Description
Compares expression
to value_1
, value_2
, ... consecutively and returns the corresponding result for the first match. If no match is found, it returns default_result
.
Argument types:
expression
—Any
value_1
—Any
result_1
—Any
value_2
—Any
result_2
—Any
default_result
—Any
Return type: Same type as (result_1
, result_2
, default_result
)
Note
Arguments (result_1
, result_2
, default_result
) must be of the same type.
Examples
CASE (
[country],
"BY", "Белоруссия",
"KZ", "Казахстан",
"RU", "Россия",
"TR", "Турция",
"UZ", "Узбекистан",
"Другая страна"
)
CASE [country]
WHEN "BY" THEN "Белоруссия"
WHEN "KZ" THEN "Казахстан"
WHEN "RU" THEN "Россия"
WHEN "TR" THEN "Турция"
WHEN "UZ" THEN "Узбекистан"
ELSE "Другая страна"
END
Data source support
Materialized Dataset
, ClickHouse 1.1
, Microsoft SQL Server 2017 (14.0)
, MySQL 5.6
, Oracle Database 12c (12.1)
, PostgreSQL 9.3
.