oracle foreign key reference table

1SELECT cons.OWNER 			AS CHILD_OWNER,
2       cons.TABLE_NAME 		AS CHILD_TABLE,
3       cons.CONSTRAINT_NAME AS CONSTAINT_NAME,
4       cons.CONSTRAINT_TYPE AS CONSTRAINT_TYPE,
5       col.OWNER 			AS PARENT_OWNER,
6       col.TABLE_NAME 		AS PARENT_TABLE,
7       col.COLUMN_NAME 		AS COLUMN_NAME
8FROM DBA_CONS_COLUMNS col, DBA_CONSTRAINTS cons
9WHERE cons.R_OWNER = col.OWNER
10  AND cons.R_CONSTRAINT_NAME = col.CONSTRAINT_NAME
11  AND cons.TABLE_NAME = 'table_name';

1SELECT c.OWNER, a.TABLE_NAME, a.COLUMN_NAME, a.CONSTRAINT_NAME, 
2       c.R_OWNER AS REF_OWNER, cpk.TABLE_NAME AS REF_TABLE, 
3       cpk.CONSTRAINT_NAME AS REF_PK
4FROM ALL_CONS_COLUMNS a 
5JOIN ALL_CONSTRAINTS c ON a.OWNER = c.OWNER
6    AND a.CONSTRAINT_NAME = c.CONSTRAINT_NAME
7 JOIN ALL_CONSTRAINTS cpk ON c.R_OWNER = cpk.OWNER
8    AND c.R_CONSTRAINT_NAME = cpk.CONSTRAINT_NAME
9WHERE c.CONSTRAINT_TYPE = 'R' AND c.TABLE_NAME= 'table_name';

1CREATE TABLE hr.admin_emp (
2         empno      NUMBER(5) PRIMARY KEY,
3         ename      VARCHAR2(15) NOT NULL,
4         ssn        NUMBER(9) ENCRYPT,
5         job        VARCHAR2(10),
6         mgr        NUMBER(5),
7         hiredate   DATE DEFAULT (sysdate),
8         photo      BLOB,
9         sal        NUMBER(7,2),
10         hrly_rate  NUMBER(7,2) GENERATED ALWAYS AS (sal/2080),
11         comm       NUMBER(7,2),
12         deptno     NUMBER(3) NOT NULL
13                     CONSTRAINT admin_dept_fkey REFERENCES hr.departments
14                     (department_id))