SQLite

Consider the following test case:

CREATE TABLE t0(c0);
CREATE TABLE t1(c0, c1 AS(1));
INSERT INTO t0 VALUES(0);
SELECT t1.c1 IS TRUE FROM t0 LEFT JOIN t1; -- expected: 0, actual: 1

Unexpectedly, the query evaluates to 1. It should evaluate to 0, because t1 does not contain any rows. This is also reflected by the following query, which does not fetch any rows:

SELECT * FROM t0 LEFT JOIN t1 WHERE t1.c1;