CASE
Syntax
As a block
As a function
CASE expression
WHEN value_1 THEN result_1
[ WHEN value_2 THEN result_2
... ]
ELSE default_result
END
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
Example with data table
Formulas:
- unit:
[unit]; - case_function:
CASE([unit], "s", 1, "m", 60, "h", 3600, 0); - case_statement:
CASE [unit] WHEN "s" THEN 1 WHEN "m" THEN 60 WHEN "h" THEN 3600 ELSE 0 END.
| unit | case_function | case_statement |
|---|---|---|
's' |
1 |
1 |
'm' |
60 |
60 |
'h' |
3600 |
3600 |
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.