>>If redeem.dredeemdat is BLANK the subselect does not catch the record, so no towfky is existent
>>
>>b.control is compared with towfky, on equal or identity if character field
>>
>>EMPTY b.control will only match EMPTY(towky), not non existent towfky
>>
>>

>>CREATE CURSOR ca (i1 c(1), d1 date)
>>INSERT INTO ca VALUES ("1", DATE())
>>INSERT INTO ca VALUES ("2", {..})
>>
>>CREATE CURSOR cb (i2 c(1),i3 c(1))
>>INSERT INTO cb VALUES ("1","A")
>>INSERT INTO cb VALUES ("2","B")
>>INSERT INTO cb VALUES ("","C")
>>
>>*no record C
>>SELECT * FROM cb WHERE i2 in (SELECT i1 FROM ca WHERE d1<=DATE()+1 AND d1>=DATE()-1)
>>
>>*no record C
>>INSERT INTO ca VALUES ("", {..})
>>SELECT * FROM cb WHERE i2 in (SELECT i1 FROM ca WHERE d1<=DATE()+1 AND d1>=DATE()-1)
>>
>>*record C
>>INSERT INTO ca VALUES ("", DATE())
>>SELECT * FROM cb WHERE i2 in (SELECT i1 FROM ca WHERE d1<=DATE()+1 AND d1>=DATE()-1)
>>

>
>

>CREATE CURSOR ca (i1 c(1), d1 date)
>INSERT INTO ca VALUES ("1", DATE())
>INSERT INTO ca VALUES ("2", {})
>
>CREATE CURSOR cb (i2 c(1),i3 c(1), i4 D)
>INSERT INTO cb VALUES ("1","A", DATE())
>INSERT INTO cb VALUES ("1","A", {})
>INSERT INTO cb VALUES ("2","B", {})
>INSERT INTO cb VALUES ("","C", {})
>
>*no record C BUT record A with empty date
>SELECT * FROM cb WHERE i2 in (SELECT i1 FROM ca WHERE d1<=DATE()+1 AND d1>=DATE()-1)
>
>*no record C BUT record A with empty date
>INSERT INTO ca VALUES ("", {..})
>SELECT * FROM cb WHERE i2 in (SELECT i1 FROM ca WHERE d1<=DATE()+1 AND d1>=DATE()-1)
>
>*record C AND record A with empty date
>INSERT INTO ca VALUES ("", DATE())
>SELECT * FROM cb WHERE i2 in (SELECT i1 FROM ca WHERE d1<=DATE()+1 AND d1>=DATE()-1)
>

>
>Are you sure that these are the records you need?

yes, those are the record you have asked for

All from cb that fit to the result of the subselect

in case 1
subselect returns
"1", cb records number 1,2 fit because i1 = "1"
in case 2
subselect returns
"1", cb records number 1,2 fit because i1 = "1"
in case 2
subselect returns
"1";"", cb records number 1,2 fit because i1 = "1" and additional ca record number 4 fit because i1 = ""

you have not asked for value of cb.i4 so it does not matter.

Update:
possibly clearer:

SELECT Cur1.* FROM cb AS Cur1 WHERE Cur1.i2 IN (SELECT Cur2.i1 FROM ca AS Cur2 WHERE Cur2.d1<=DATE()+1 AND Cur2.d1>=DATE()-1)

This is exactly the same as above, only with aliases mentioned