Parent-child how to ?

Question

Hi all,
How to write query for getting all master and child columns in my schema and getting it stored in a table.
regards
asp

Answer 1

You mean query all the constraints? I'm sure this has been answered here before but here's how to query the constraints (far from perfect, but it can give you an idea):
SQL> set lines 100
SQL> col master_table  format a16
SQL> col detail_table  format a15
SQL> col master_column format a15
SQL> col detail_column format a15
SQL> select uc.constraint_name
  2       , nvl( m.table_name
  3            , DECODE( uc.constraint_type
  4                    , 'U', 'Unique key'
  5                    , 'P', 'Primary key'
  6                    , 'C', 'Check constraint'
  7                    )
  8            ) master_table
  9       , m.column_name master_column
10       , c.table_name  detail_table
11       , c.column_name detail_column
12  from   user_cons_columns m
13       , user_cons_columns c
14       , user_constraints  uc
15  where  uc.constraint_name = c.constraint_name
16  and    uc.r_constraint_name = m.constraint_name(+)
17  and    nvl(m.position, c.position) = c.position
18  /
CONSTRAINT_NAME                MASTER_TABLE     MASTER_COLUMN   DETAIL_TABLE    DETAIL_COLUMN
LOC_C_ID_FK                    COUNTRIES        COUNTRY_ID      LOCATIONS       COUNTRY_ID
EMP_DEPT_FK                    DEPARTMENTS      DEPARTMENT_ID   EMPLOYEES       DEPARTMENT_ID
JHIST_DEPT_FK                  DEPARTMENTS      DEPARTMENT_ID   JOB_HISTORY     DEPARTMENT_ID
DEPT_MGR_FK                    EMPLOYEES        EMPLOYEE_ID     DEPARTMENTS     MANAGER_ID
EMP_MANAGER_FK                 EMPLOYEES        EMPLOYEE_ID     EMPLOYEES       MANAGER_ID
JHIST_EMP_FK                   EMPLOYEES        EMPLOYEE_ID     JOB_HISTORY     EMPLOYEE_ID
EMP_JOB_FK                     JOBS             JOB_ID          EMPLOYEES       JOB_ID
JHIST_JOB_FK                   JOBS             JOB_ID          JOB_HISTORY     JOB_ID
DEPT_LOC_FK                    LOCATIONS        LOCATION_ID     DEPARTMENTS     LOCATION_ID
COUNTR_REG_FK                  REGIONS          REGION_ID       COUNTRIES       REGION_ID
JHIST_EMP_ID_ST_DATE_PK        Primary key                      JOB_HISTORY     EMPLOYEE_ID
CONSTRAINT_NAME                MASTER_TABLE     MASTER_COLUMN   DETAIL_TABLE    DETAIL_COLUMN
JOB_ID_PK                      Primary key                      JOBS            JOB_ID
REG_ID_PK                      Primary key                      REGIONS         REGION_ID
LOC_ID_PK                      Primary key                      LOCATIONS       LOCATION_ID
JHIST_EMP_ID_ST_DATE_PK        Primary key                      JOB_HISTORY     START_DATE
EMP_EMP_ID_PK                  Primary key                      EMPLOYEES       EMPLOYEE_ID
EMP_EMAIL_UK                   Unique key                       EMPLOYEES       EMAIL
DEPT_ID_PK                     Primary key                      DEPARTMENTS     DEPARTMENT_ID
COUNTRY_C_ID_PK                Primary key                      COUNTRIES       COUNTRY_ID
19 rows selected.
SQL> MHE