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—Anyvalue_1—Anyresult_1—Anyvalue_2—Anyresult_2—Anydefault_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 19.13, Microsoft SQL Server 2017 (14.0), MySQL 5.6, Oracle Database 12c (12.1), PostgreSQL 9.3, YDB.