delete multiple rows from different tables on oracle - sql

Question

I have a two table.One of them is student, the other one is salary.
Student table
id | name | code | status
1 | steven | 123 | 100
2 | joe | 678 | 200
3 | paul | 758 | 100
Salary table
id | code | status | currency
1 | 123 | 100 | euro
2 | 678 | 200 | dolar
3 | 758 | 520 | yuan
I want to delete row1 from Student table and row 1 and 2 from Salary table because code and status fields
are same.
I write that query
delete a,b Student as a , join Salary as b
on a.code= b.code and a.status = b.status
but it is not working.I want to delete rows with one query.Do you have any idea?

Answer 1

Would something like this do? PL/SQL, though, not SQL.
Initial data sets:
SQL> select * from student;
ID NAME CODE STATUS
---------- ------ ---------- ----------
1 steven 123 100
2 joe 678 200
3 paul 758 100
SQL> select * from salary;
ID CODE STATUS CURREN
---------- ---------- ---------- ------
1 123 100 euro
2 678 200 dollar
3 758 520 yuan
Remove common (CODE, STATUS) combinations:
SQL> begin
2 for cur_r in (select code, status from student
3 intersect
4 select code, status from salary
5 )
6 loop
7 delete from student where code = cur_r.code and status = cur_r.status;
8 delete from salary where code = cur_r.code and status = cur_r.status;
9 end loop;
10 end;
11 /
PL/SQL procedure successfully completed.
Result:
SQL> select * from student;
ID NAME CODE STATUS
---------- ------ ---------- ----------
3 paul 758 100
SQL> select * from salary;
ID CODE STATUS CURREN
---------- ---------- ---------- ------
3 758 520 yuan
SQL>

Answer 2

You can use two statements to do so easily:
delete student s where exists(
select * from student stu inner join salary sal on stu.code=sal.code and stu.status=sal.status and stu.id=s.id);
delete salary sal where not exists (select code from student stu where stu.code=sal.code);
First one to delete all the students having same code and status in both tables and second is to delete all the rows from salary table where code doesn't exist in student table.