List of foreign keys and the tables they reference in Oracle DB

Question

The referenced primary key is described in the columns r_owner and r_constraint_name of the table ALL_CONSTRAINTS. This will give you the info you want:

SELECT a.table_name, a.column_name, a.constraint_name, c.owner, 
       -- referenced pk
       c.r_owner, c_pk.table_name r_table_name, c_pk.constraint_name r_pk
  FROM all_cons_columns a
  JOIN all_constraints c ON a.owner = c.owner
                        AND a.constraint_name = c.constraint_name
  JOIN all_constraints c_pk ON c.r_owner = c_pk.owner
                           AND c.r_constraint_name = c_pk.constraint_name
 WHERE c.constraint_type = 'R'
   AND a.table_name = :TableName

Try this:

select * from all_constraints where r_constraint_name in (select constraint_name 
from all_constraints where table_name='YOUR_TABLE_NAME');

Here is an all-purpose script we use that has been incredibly handy.

Save it off so you can execute it directly (@fkeys.sql). It will let you search by Owner and either the Parent or Child table and show foreign key relationships. The current script does explicitly spool to C:\SQLRPTS so you will need to create that folder of change that line to something you want to use.

REM ########################################################################
REM ##
REM ##   fkeys.sql
REM ##
REM ##   Displays the foreign key relationships
REM ##
REM #######################################################################

CLEAR BREAK
CLEAR COL
SET LINES 200
SET PAGES 54
SET NEWPAGE 0
SET WRAP OFF
SET VERIFY OFF
SET FEEDBACK OFF

break on table_name skip 2 on constraint_name on r_table_name skip 1

column CHILDCOL format a60 head 'CHILD COLUMN'
column PARENTCOL format a60 head 'PARENT COLUMN'
column constraint_name format a30 head 'FK CONSTRAINT NAME'
column delete_rule format a15
column bt noprint
column bo noprint

TTITLE LEFT _DATE CENTER 'FOREIGN KEY RELATIONSHIPS ON &new_prompt' RIGHT 'PAGE:'FORMAT 999 SQL.PNO SKIP 2

SPOOL C:\SQLRPTS\FKeys_&new_prompt
ACCEPT OWNER_NAME PROMPT 'Enter Table Owner (or blank for all): '
ACCEPT PARENT_TABLE_NAME PROMPT 'Enter Parent Table or leave blank for all: '
ACCEPT CHILD_TABLE_NAME PROMPT 'Enter Child Table or leave blank for all: '

  select b.owner || '.' || b.table_name || '.' || b.column_name CHILDCOL,
         b.position,
         c.owner || '.' || c.table_name || '.' || c.column_name PARENTCOL,
         a.constraint_name,
         a.delete_rule,
         b.table_name bt,
         b.owner bo
    from all_cons_columns b,
         all_cons_columns c,
         all_constraints a
   where b.constraint_name = a.constraint_name
     and a.owner           = b.owner
     and b.position        = c.position
     and c.constraint_name = a.r_constraint_name
     and c.owner           = a.r_owner
     and a.constraint_type = 'R'
     and c.owner      like case when upper('&OWNER_NAME') is null then '%'
                                else upper('&OWNER_NAME') end
     and c.table_name like case when upper('&PARENT_TABLE_NAME') is null then '%'
                                else upper('&PARENT_TABLE_NAME') end
     and b.table_name like case when upper('&CHILD_TABLE_NAME') is null then '%'
                                else upper('&CHILD_TABLE_NAME') end
order by 7,6,4,2
/
SPOOL OFF
TTITLE OFF
SET FEEDBACK ON
SET VERIFY ON
CLEAR BREAK
CLEAR COL
SET PAGES 24
SET LINES 100
SET NEWPAGE 1
UNDEF OWNER

This will travel the hierarchy of foreign keys for a given table and column and return columns from child and grandchild, and all descendant tables. It uses sub-queries to add r_table_name and r_column_name to user_constraints, and then uses them to connect rows.

select distinct table_name, constraint_name, column_name, r_table_name, position, constraint_type 
from (
    SELECT uc.table_name, 
    uc.constraint_name, 
    cols.column_name, 
    (select table_name from user_constraints where constraint_name = uc.r_constraint_name) 
        r_table_name,
    (select column_name from user_cons_columns where constraint_name = uc.r_constraint_name and position = cols.position) 
        r_column_name,
    cols.position,
    uc.constraint_type
    FROM user_constraints uc
    inner join user_cons_columns cols on uc.constraint_name = cols.constraint_name 
    where constraint_type != 'C'
) 
start with table_name = 'MY_TABLE_NAME' and column_name = 'MY_COLUMN_NAME'  
connect by nocycle 
prior table_name = r_table_name 
and prior column_name = r_column_name;

Here is an another solution. Using sys's default views are so slow (approx 10s in my situation). This is much faster than that (approx. 0.5s).

SELECT
    CONST.NAME AS CONSTRAINT_NAME,
    RCONST.NAME AS REF_CONSTRAINT_NAME,

    OBJ.NAME AS TABLE_NAME,
    COALESCE(ACOL.NAME, COL.NAME) AS COLUMN_NAME,
    CCOL.POS# AS POSITION,

    ROBJ.NAME AS REF_TABLE_NAME,
    COALESCE(RACOL.NAME, RCOL.NAME) AS REF_COLUMN_NAME,
    RCCOL.POS# AS REF_POSITION
FROM SYS.CON$ CONST
INNER JOIN SYS.CDEF$ CDEF ON CDEF.CON# = CONST.CON#
INNER JOIN SYS.CCOL$ CCOL ON CCOL.CON# = CONST.CON#
INNER JOIN SYS.COL$ COL  ON (CCOL.OBJ# = COL.OBJ#) AND (CCOL.INTCOL# = COL.INTCOL#)
INNER JOIN SYS.OBJ$ OBJ ON CCOL.OBJ# = OBJ.OBJ#
LEFT JOIN SYS.ATTRCOL$ ACOL ON (CCOL.OBJ# = ACOL.OBJ#) AND (CCOL.INTCOL# = ACOL.INTCOL#)

INNER JOIN SYS.CON$ RCONST ON RCONST.CON# = CDEF.RCON#
INNER JOIN SYS.CCOL$ RCCOL ON RCCOL.CON# = RCONST.CON#
INNER JOIN SYS.COL$ RCOL  ON (RCCOL.OBJ# = RCOL.OBJ#) AND (RCCOL.INTCOL# = RCOL.INTCOL#)
INNER JOIN SYS.OBJ$ ROBJ ON RCCOL.OBJ# = ROBJ.OBJ#
LEFT JOIN SYS.ATTRCOL$ RACOL  ON (RCCOL.OBJ# = RACOL.OBJ#) AND (RCCOL.INTCOL# = RACOL.INTCOL#)

WHERE CONST.OWNER# = userenv('SCHEMAID')
  AND RCONST.OWNER# = userenv('SCHEMAID')
  AND CDEF.TYPE# = 4  /* 'R' Referential/Foreign Key */;

If you need all the foreign keys of the user then use the following script

SELECT a.constraint_name, a.table_name, a.column_name,  c.owner, 
       c_pk.table_name r_table_name,  b.column_name r_column_name
  FROM user_cons_columns a
  JOIN user_constraints c ON a.owner = c.owner
       AND a.constraint_name = c.constraint_name
  JOIN user_constraints c_pk ON c.r_owner = c_pk.owner
       AND c.r_constraint_name = c_pk.constraint_name
  JOIN user_cons_columns b ON C_PK.owner = b.owner
       AND  C_PK.CONSTRAINT_NAME = b.constraint_name AND b.POSITION = a.POSITION     
 WHERE c.constraint_type = 'R'

based on Vincent Malgrat code

I know it's kinda late to answer but let me answer anyway, some of the answers above are quite complicated hence here is a much simpler take.

SELECT a.table_name child_table, a.column_name child_column, a.constraint_name, 
      b.table_name parent_table, b.column_name parent_column
  FROM all_cons_columns a
  JOIN all_constraints c ON a.owner = c.owner AND a.constraint_name = c.constraint_name
 join all_cons_columns b on c.owner = b.owner and c.r_constraint_name = b.constraint_name
 WHERE c.constraint_type = 'R'
   AND a.table_name = 'your table name'