Postgres 16

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create table test(id,val) as values
(1,3),
(2,null),
(3,3);

SELECT 3


select *
from test
where id<4
and (case
         when true/*:myFlag*/ then val in (1,3/*:values*/)
         else val in (1,3/*:values*/) or val is null
     end)


id
val


1
3

3
3



SELECT 2


select *
from test
where id<4
and (case
         when false/*:myFlag*/ then val in (1,3/*:values*/)
         else val in (1,3/*:values*/) or val is null
     end)


id
val


1
3

2
null

3
3



SELECT 3


select *
from test
where id<4
and (case
         when true/*:myFlag*/ then val in (1,3/*:values*/) or val is null
         else true
     end)


id
val


1
3

2
null

3
3



SELECT 3


select *
from test
where id<4
and (case
         when false/*:myFlag*/ then val in (1,3/*:values*/) or val is null
         else true
     end)


id
val


1
3

2
null

3
3



SELECT 3

id	val
1	3
2	null
3	3

id	val
1	3
2	null
3	3

id	val
1	3
2	null
3	3