How to find the level of each child table in a relational model?

Question

Earthlings,
I need your help and I know that, 'yes, we can change'. Change this thread to a answered question.
So: How to find the level of each child table in a relational model?
I have a relacional database (9.2), all right?!
     O /* This is a child who makes N references to each of the follow N parent tables (here: three), and so on. */
    /↑\ Fks
   O"O O" <-- level 2 for first table (circle)
  /↑\ Fks
"o"o"o" <-- level 1 for middle table (circle)
   ↑ Fk
  "º"Tips:
- each circle represents a table;
- red tables no have foreign key
- the table in first line of tree, for example, has level 3, but when 3 becomes N? How much is N? This's the question.
I started thinking about the following:
First I have to know how to take the children:
select distinct child.table_name child
  from all_cons_columns father
  join all_cons_columns child
using (owner, position)
  join (select child.owner,
               child.constraint_name fk,
               child.table_name child,
               child.r_constraint_name pk,
               father.table_name father
          from all_constraints father, all_constraints child
         where child.r_owner = father.owner
           and child.r_constraint_name = father.constraint_name
           and father.constraint_type in ('P', 'U')
           and child.constraint_type = 'R'
           and child.owner = 'OWNER') aux
using (owner)
where child.constraint_name = aux.fk
   and child.table_name = aux.child
   and father.constraint_name = aux.pk
   and father.table_name = aux.father;Thinking...
Let's Share!
My thanks in advance,
Philips
Edited by: BluShadow on 01-Apr-2011 15:08
formatted the code and the hierarchy for readbility

Answer 1

Justin,
Understood.
Nocycle not work in 9.2 and, even that would work, would not be appropriate.
With your help, I decided a much simpler way (but there is still a small problem, <font color=red>IN RED</font>):
-- 1
declare
  type udt_roles is table of varchar2(30) index by pls_integer;
  cRoles udt_roles;
begin
  execute immediate 'create user philips
    identified by philips';
  select granted_role bulk collect
    into cRoles
    from user_role_privs
   where username = user;
  for i in cRoles.first .. cRoles.count loop
    execute immediate 'grant ' || cRoles(i) || ' to philips';
  end loop;
end;
-- 2
create table philips.root1(root1_id number,
                           constraint root1_id_pk primary key(root1_id)
                           enable);
grant all on philips.root1 to philips;
create or replace trigger philips.tgr_root1
   before delete or insert or update on philips.root1
   begin
     null;
   end;
create table philips.root2(root2_id number,
                           constraint root2_id_pk primary key(root2_id)
                           enable);
grant all on philips.root2 to philips;
create or replace trigger philips.tgr_root2
   before delete or insert or update on philips.root2
   begin
     null;
   end;
create table philips.node1(node1_id number,
                           root1_id number,
                           node2_id number,
                           node4_id number,
                           constraint node1_id_pk primary key(node1_id)
                           enable,
                           constraint n1_r1_id_fk foreign key(root1_id)
                           references philips.root1(root1_id) enable,
                           constraint n1_n2_id_fk foreign key(node2_id)
                           references philips.node2(node2_id) enable,
                           constraint n1_n4_id_fk foreign key(node4_id)
                           references philips.node4(node4_id) enable);
grant all on philips.node1 to philips;
create or replace trigger philips.tgr_node1
   before delete or insert or update on philips.node1
   begin
     null;
   end;
create table philips.node2(node2_id number,
                           root1_id number,
                           node3_id number,
                           constraint node2_id_pk primary key(node2_id)
                           enable,
                           constraint n2_r1_id_fk foreign key(root1_id)
                           references philips.root1(root1_id) enable,
                           constraint n2_n3_id_fk foreign key(node3_id)
                           references philips.node3(node3_id) enable);
grant all on philips.node2 to philips;
create or replace trigger philips.tgr_node2
   before delete or insert or update on philips.node2
   begin
     null;
   end;                          
create table philips.node3(node3_id number,
                           root2_id number,
                           constraint node3_id_pk primary key(node3_id)
                           enable,
                           constraint n3_r2_id_fk foreign key(root2_id)
                           references philips.root2(root2_id) enable);
grant all on philips.node3 to philips;
create or replace trigger philips.tgr_node3
   before delete or insert or update on philips.node3
   begin
     null;
   end;                          
create table philips.node4(node4_id number,
                           node2_id number,
                           constraint node4_id_pk primary key(node4_id)
                           enable,
                           constraint n4_n2_id_fk foreign key(node2_id)
                           references philips.node2(node2_id) enable);
grant all on philips.node4 to philips;
create or replace trigger philips.tgr_node4
   before delete or insert or update on philips.node4
   begin
     null;
   end;                          
-- out of the relational model
create table philips.node5(node5_id number,
                           constraint node5_id_pk primary key(node5_id)
                           enable);
grant all on philips.node5 to philips;
create or replace trigger philips.tgr_node5
   before delete or insert or update on philips.node5
   begin
     null;
   end;
-- 3
create table philips.dictionary(table_name varchar2(30));
insert into philips.dictionary values ('ROOT1');
insert into philips.dictionary values ('ROOT2');
insert into philips.dictionary values ('NODE1');
insert into philips.dictionary values ('NODE2');
insert into philips.dictionary values ('NODE3');
insert into philips.dictionary values ('NODE4');
insert into philips.dictionary values ('NODE5');
--4
create or replace package body philips.pck_restore_philips as
  procedure sp_select_tables is
    aExportTablesPhilips     utl_file.file_type := null; -- file to write DDL of tables   
    aExportReferencesPhilips utl_file.file_type := null; -- file to write DDL of references
    aExportIndexesPhilips    utl_file.file_type := null; -- file to write DDL of indexes
    aExportGrantsPhilips     utl_file.file_type := null; -- file to write DDL of grants
    aExportTriggersPhilips   utl_file.file_type := null; -- file to write DDL of triggers
    sDirectory               varchar2(100) := '/app/oracle/admin/tace/utlfile'; -- directory \\bmduhom01or02 
    cTables                  udt_tables; -- collection to store table names for the relational depth
  begin
    -- omits all referential constraints:
    dbms_metadata.set_transform_param(dbms_metadata.session_transform, 'REF_CONSTRAINTS', false);
    -- omits segment attributes (physical attributes, storage attributes, tablespace, logging):
    dbms_metadata.set_transform_param(dbms_metadata.session_transform, 'SEGMENT_ATTRIBUTES', false);
    -- append a SQL terminator (; or /) to each DDL statement:
    dbms_metadata.set_transform_param(dbms_metadata.session_transform, 'SQLTERMINATOR', true);
    -- create/open files for export DDL:
    aExportTablesPhilips := utl_file.fopen(sDirectory, 'DDLTablesPhilips.pdc', 'w', 32767);
    aExportReferencesPhilips := utl_file.fopen(sDirectory, 'DDLReferencesPhilips.pdc', 'w', 32767);
    aExportIndexesPhilips := utl_file.fopen(sDirectory, 'DDLIndexesPhilips.pdc', 'w', 32767);
    aExportGrantsPhilips := utl_file.fopen(sDirectory, 'DDLGrantsPhilips.pdc', 'w', 32767);
    aExportTriggersPhilips := utl_file.fopen(sDirectory, 'DDLTriggersPhilips.pdc', 'w', 32767);
    select d.table_name bulk collect
      into cTables -- collection with the names of tables in the schema philips
      from all_tables t, philips.dictionary d
     where owner = 'PHILIPS'
       and t.table_name = d.table_name;
    -- execution
    sp_seeks_ddl(aExportTablesPhilips,
                 aExportReferencesPhilips,
                 aExportIndexesPhilips,
                 aExportGrantsPhilips,
                 aExportTriggersPhilips,
                 cTables);
    -- closes all files
    utl_file.fclose_all;
  end sp_select_tables;
  procedure sp_seeks_ddl(aExportTablesPhilips     in utl_file.file_type,
                         aExportReferencesPhilips in utl_file.file_type,
                         aExportIndexesPhilips    in utl_file.file_type,
                         aExportGrantsPhilips     in utl_file.file_type,
                         aExportTriggersPhilips   in utl_file.file_type,
                         cTables                  in out nocopy udt_tables) is
    cDDL       clob := null; -- colletion to save DDL
    plIndex    pls_integer := null;
    sTableName varchar(30) := null;
  begin
    for i in cTables.first .. cTables.count loop
      plIndex    := i;
      sTableName := cTables(plIndex);
       * Retrieves the DDL and the dependent DDL into cDDL clob       *      
      * for the selected table in the collection, and writes to file.*
      begin
        cDDL := dbms_metadata.get_ddl('TABLE', sTableName, 'PHILIPS');
        sp_writes_ddl(aExportTablesPHILIPS, cDDL);
      exception
        when dbms_metadata.object_not_found then
          null;
      end;
      begin
        cDDL := dbms_metadata.get_dependent_ddl('REF_CONSTRAINT', sTableName, 'PHILIPS');
        sp_writes_ddl(aExportReferencesPhilips, cDDL);
      exception
        when dbms_metadata.object_not_found2 then
          null;
      end;
      begin
        cDDL := dbms_metadata.get_dependent_ddl('INDEX', sTableName, 'PHILIPS');
        sp_writes_ddl(aExportIndexesPhilips, cDDL);
      exception
        when dbms_metadata.object_not_found2 then
          null;
      end;
      begin
        cDDL := dbms_metadata.get_dependent_ddl('OBJECT_GRANT', sTableName, 'PHILIPS');
        sp_writes_ddl(aExportGrantsPhilips, cDDL);
      exception
        when dbms_metadata.object_not_found2 then
          null;
      end;
      begin
        cDDL := dbms_metadata.get_dependent_ddl('TRIGGER', sTableName, 'PHILIPS');
        sp_writes_ddl(aExportTriggersPhilips, cDDL);
      exception
        when dbms_metadata.object_not_found2 then
          null;
      end;
    end loop;
  end sp_seeks_ddl;
  procedure sp_writes_ddl(aExport in utl_file.file_type,
                          cDDL    in out nocopy clob) is
    pLengthDDL  pls_integer := length(cDDL);
    plQuotient  pls_integer := null;
    plRemainder pls_integer := null;
  begin
      * Register variables to control the amount of lines needed   *
     * for each DDL and the remaining characters to the last row. *
    select trunc(pLengthDDL / 32766), mod(pLengthDDL, 32766)
      into plQuotient, plRemainder
      from dual;
      * Join DDL in the export file.                            *
     * ps. 32766 characters + 1 character for each line break. *
    -- if the size of the DDL is greater than or equal to limit the line ...
    if plQuotient >= 1 then
      -- loops for substring (lines of 32766 characters + 1 break character):
      for i in 1 .. plQuotient loop
        utl_file.put_line(aExport, substr(cDDL, 1, 32766));
        -- removes the last line, of clob, recorded in the buffer:
        cDDL := substr(cDDL, 32767, length(cDDL) - 32766);
      end loop;
    end if;
      * If any remains or the number of characters is less than the threshold (quotient = 0), *
     * no need to substring.                                                                 *
    if plRemainder > 0 then
      utl_file.put_line(aExport, cDDL);
    end if;
    -- record DDL buffered in the export file:
    utl_file.fflush(aExport);
  end sp_writes_ddl;
begin
  -- executes main procedure:
  sp_select_tables;
end pck_restore_philips;<font color="red">The problem is that I still have ...
When creating the primary key index is created and this is repeated in the file indexes.
How to avoid?</font>