Code Inspection: Constant expression

Reports conditions and expressions that are always true, false or null.

Example (MySQL):

CREATE TABLE t1 (a TEXT, b INT, c BOOLEAN);
SELECT a FROM t1 WHERE 'Cat' = 'Cat';
SELECT a FROM t1 WHERE 'Cat' = null;

The 'Cat' = 'Cat' is always true and will be reported.

The 'Cat' = null is always null and will be reported.