Case is a conditional SQL expression : It returns the value of a different expression (formula in then or else branch) based on one or more conditions in the when clause.
SELECT CASE WHEN column_name > 100 THEN 'too large'
ELSE 'ok'
END
FROM …Related
Tutorial:
Case— Conditional ExpressionsAbbreviations:
case … when …(simple case),coalesce,nullif.Product specific features:
if,iif,decode.
Normative References
The searched case expression is defined in ISO/IEC 9075:2016-2 as mandatory feature F261-02.
