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 — 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],
    "AO", "Angola",
    "AU", "Australia",
    "BY", "Belarus",
    "CA", "Canada",
    "TT", "Trinidad and Tobago",
    "Other Country"
)

CASE [country]
    WHEN "AO" THEN "Angola"
    WHEN "AU" THEN "Australia"
    WHEN "BY" THEN "Belarus"
    WHEN "CA" THEN "Canada"
    WHEN "TT" THEN "Trinidad and Tobago"
    ELSE "Other Country"
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

ClickHouse 19.13, Microsoft SQL Server 2017 (14.0), MySQL 5.6, PostgreSQL 9.3.

Overview