DBA_CONSTRAINTS - self join - duplicate rows?

Question

Hi,
I have two tables in 'I' schema.
===========
SQL> desc dept;
Name Null? Type
DEPTNO NOT NULL NUMBER(2) DNAME VARCHAR2(14)
LOC VARCHAR2(13)
DEPT.DEPTNO - pk_dept_deptno - PRIMARY KEY
SQL> desc emp;
Name Null? Type
EMPNO NOT NULL NUMBER(4)
ENAME VARCHAR2(10)
JOB VARCHAR2(9)
MGR NUMBER(4)
HIREDATE DATE
SAL NUMBER(7,2)
COMM NUMBER(7,2)
DEPTNO NUMBER(2)
EMP.DEPTNO - fk_emp_deptno - FORIGN KEY (DEPT. DEPTNO)
SQL> desc emp2
Name Null? Type
DEPTNO NUMBER
FUNCTION VARCHAR2(10)
EMP2 . DEPTNO - fk_emp2_deptno - FORIGN KEY (DEPT. DEPTNO)
I executed the query as DBA,
SQL>
select p.constraint_name,p.table_name,p.r_constraint_name,r.constraint_name,r.table_name
from dba_constraints p, dba_constraints r
where p.r_constraint_name=r.constraint_name and p.owner='I'
order by p.constraint_name;
CONSTRAINT_NAME | TABLE_NAME | R_CONSTRAINT_NAME | CONSTRAINT_NAME | TABLE_NAME
FK_EMP2_DEPTNO | EMP2 | PK_DEPT_DEPTNO | PK_DEPT_DEPTNO | DEPT
FK_EMP2_DEPTNO | EMP2 | PK_DEPT_DEPTNO | PK_DEPT_DEPTNO | DEPT
FK_EMP_DEPTNO | EMP | PK_DEPT_DEPTNO | PK_DEPT_DEPTNO | DEPT
FK_EMP_DEPTNO | EMP | PK_DEPT_DEPTNO | PK_DEPT_DEPTNO|
DEPT
Why I am getting duplicate rows? Any think wrong in my query?
regards
Mathew

Answer 1

Hi,
You can query on USER_CONSTRAINTS instead of DBA_CONSTRAINTS.
SQL> ed
Wrote file afiedt.buf
  1  select p.constraint_name, p.table_name, p.r_constraint_name, r.constraint_n
ame, r.table_name
  2  from user_constraints p , user_constraints r
  3* where p.r_constraint_name = r.constraint_name
  4  /
SQL> /
CONSTRAINT_NAME TABLE_NAME      R_CONSTRAINT_NA CONSTRAINT_NAME TABLE_NAME
SYS_C005292     B               PK_NO           PK_NO           A
FK_DEPTNO       EMP             PK_DEPT         PK_DEPT         DEPT
SQL> ed
Wrote file afiedt.buf
  1  select p.constraint_name, p.table_name, p.r_constraint_name, r.constraint_n
ame, r.table_name
  2  from dba_constraints p , dba_constraints r
  3  where p.r_constraint_name = r.constraint_name
  4  and p.owner = 'SCOTT'
  5* order by p.constraint_name
SQL> conn sys as sysdba
Enter password:
Connected.
SQL> /
CONSTRAINT_NAME TABLE_NAME      R_CONSTRAINT_NA CONSTRAINT_NAME TABLE_NAME
FK_DEPTNO       EMP             PK_DEPT         PK_DEPT         DEPT
SYS_C005292     B               PK_NO           PK_NO           A
SYS_C005292     B               PK_NO           PK_NO           A
SQL>Message was edited by:
Mohammad Taj