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This is experimental functionality, and as such subject to change. Use at your own risk!
CASE searched to CASE simple
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
A searched CASE expression can be simplified into a simple
CASE expression, if it always equality compares the same expression.
Using Settings.transformPatternsCaseSearchedToCaseSimple, the following transformations can be achieved:
-- With Settings.transformPatternsCaseSearchedToCaseSimple active, this: SELECT CASE WHEN a = b THEN 1 END, CASE WHEN a = b THEN 1 WHEN a = c THEN 2 ELSE 3 END FROM tab; -- ... is transformed into the equivalent expression: SELECT CASE a WHEN b THEN 1 END, CASE a WHEN b THEN 1 WHEN c THEN 2 ELSE 3 END FROM tab;