CREATE TABLE t1(x);
INSERT INTO t1 VALUES(0), (2);
CREATE VIRTUAL TABLE vt1 USING tcl(vtab_command t1);
select * from vt1
select * from vt1 WHERE a=0
select * from vt1 WHERE a=1
select * from vt1 WHERE a=1 OR a=0
UPDATE t1 SET x=NULL WHERE x=2;
select * from vt1
select * from vt1 WHERE a=0
select * from vt1 WHERE a=1
select * from vt1 WHERE a=1 OR a=0
select * from vt1 WHERE a IN (2)
select * from vt1 WHERE a IN (0,1,2,3)
select * from vt1 WHERE a IN (0, NULL)
select * from vt1 WHERE a IN (NULL)