Upper and lower case in query

Database query return last name having first name:

Select.one(db,tabUser.colLastName()).where(tabUser.colFirstName(),EQ,"Klaudiusz").result();

SQL:

select ihs1.LAST_NAME
 from USER1 ihs1 
 where  ihs1.FIRST_NAME = 'Klaudiusz'

Result:

Wojtkowiak

upper case:

Select.one(db,tabUser.colLastName().upper()).where(tabUser.colFirstName(),EQ,"Klaudiusz").result();

SQL:

select upper(ihs1.LAST_NAME)
 from USER1 ihs1 
 where  ihs1.FIRST_NAME = 'Klaudiusz'

Result:

WOJTKOWIAK

lower case:

Select.one(db,tabUser.colLastName().lower()).where(tabUser.colFirstName(),EQ,"Klaudiusz").result();

SQL:

select lower(ihs1.LAST_NAME)
 from USER1 ihs1 
 where  ihs1.FIRST_NAME = 'Klaudiusz'

Result:

wojtkowiak

Find by lower case:

Select.one(db,tabUser.colLastName()).where(tabUser.colFirstName(),EQ,Lower.of("Klaudiusz")).result();

SQL:

select ihs1.LAST_NAME
 from USER1 ihs1 
 where  ihs1.FIRST_NAME = lower('Klaudiusz')

Result:

null

Find by lower case column and value:

Select.one(db,tabUser.colLastName()).where(tabUser.colFirstName().lower(),EQ,Lower.of("Klaudiusz")).result();

SQL:

select ihs1.LAST_NAME
 from USER1 ihs1 
 where  lower(ihs1.FIRST_NAME) = lower('Klaudiusz')

Result:

Wojtkowiak