Question

is it possible to query in this way like ‘OR’ function.

Updated example:

Select S.*, U.* from Staff S, Unit U where S.Unit='' OR S.Unit= U.UnitCode;

Staff Table Schema:

Staff ID, Staff Name, UnitCode, StaffNumber

Unit Schema:

UnitCode, ClassCode

The above updated example works. But the staff records whom unit is blank will be duplicated with all the unit codes.

For example of results output:

Staff ID     Staff Name     UnitCode     ClassCode    Staff Number
1            John            IT1         B123         234
2            Sally           BUS2        B234         0589
3            Johnson         IT1         B123          111
4            Johnson         BUS2        B234          111

Thanks

Answer 1

Since you are using SQLite, Use OR instead of ||

Select S.*, U.* 
from Staff S, Unit U 
where S.Unit = '' OR S.Unit= U.UnitCode;

What is the result if I removed this condition? S.Unit = ''

Select S.*, U.* 
from Staff S INNER JOIN Unit U 
         on S.Unit = U.UnitCode;

UPDATE 1

can you try this one?

SELECT x.*
FROM Staff x INNER JOIN
    (Select DISTINCT S.StaffID
     from Staff S INNER JOIN Unit U 
             on (S.Unit = U.UnitCode) OR
                (S.Unit = '')
     ) y ON x.StaffID = y.StaffID