List all employees who attended XML course and Java course : Correlated Subquery « Query Select « Oracle PL/SQL Tutorial






  1. Oracle PL/SQL Tutorial
  2. Query Select
  3. Correlated Subquery
SQL>
SQL>
SQL> create table registrations
  2  ( attendee    NUMBER(4)
  3  , course      VARCHAR2(6)
  4  , begindate   DATE
  5  , evaluation  NUMBER(1)) ;

Table created.

SQL>
SQL>
SQL> insert into registrations values (1, 'SQL',date '1999-04-12',4   );

1 row created.

SQL> insert into registrations values (2, 'SQL',date '1999-12-13',NULL);

1 row created.

SQL> insert into registrations values (3, 'SQL',date '1999-12-13',NULL);

1 row created.

SQL> insert into registrations values (4, 'OAU',date '1999-08-10',4   );

1 row created.

SQL> insert into registrations values (5, 'OAU',date '2000-09-27',5   );

1 row created.

SQL> insert into registrations values (6, 'JAV',date '1999-12-13',2   );

1 row created.

SQL> insert into registrations values (7, 'JAV',date '2000-02-01',4   );

1 row created.

SQL> insert into registrations values (8, 'JAV',date '2001-02-01',5   );

1 row created.

SQL> insert into registrations values (9, 'XML',date '2002-02-03',4   );

1 row created.

SQL> insert into registrations values (10,'XML',date '2003-02-03',5   );

1 row created.

SQL> insert into registrations values (1, 'PLS',date '2004-09-11',NULL);

1 row created.

SQL> insert into registrations values (2, 'PLS',date '2005-09-11',NULL);

1 row created.

SQL> insert into registrations values (3, 'PLS',date '2006-09-11',NULL);

1 row created.

SQL>
SQL>
SQL> select attendee
  2  from   registrations
  3  where  course   = 'JAV'
  4  and    attendee in (select attendee
  5                      from   registrations
  6                      where  course = 'XML');

no rows selected

SQL>
SQL> drop table registrations;

Table dropped.








2.37.Correlated Subquery
2.37.1.Writing Correlated Subqueries
2.37.2.Using EXISTS and NOT EXISTS with a Correlated Subquery
2.37.3.A correlated subquery: the subquery references a column from a table referred to in the parent statement.
2.37.4.The subquery returning the literal value 1
2.37.5.Using NOT EXISTS with a Correlated Subquery
2.37.6.list all employees who is younger than Joe
2.37.7.List all employees who attended XML course and Java course
2.37.8.Extract a Subset of the Results
2.37.9.How Many Products By Department with correlated subqueries 1
2.37.10.How Many Products By Department with correlated subqueries 2
2.37.11.Correlated subquery using the EXISTS operator