l_stm = 'CREATE TABLE ' || table_name || ' ( ';


  FOR SELECT column_name, data_type
      FROM all_tab_columns
      WHERE table_name = 'T3'
      INTO :l_field_name, :l_data_type
  DO BEGIN
    l_stm = l_stm || :l_field_name || ' ' || :l_data_type || ' ';

    SUSPEND;
  END
l_stm = l_stm || ' )' ;

  
  DECLARE VARIABLE l_old_table_name VARCHAR( 60 );
  DECLARE VARIABLE l_new_table_name VARCHAR( 60 );
  DECLARE VARIABLE l_field_name VARCHAR( 50 );
  DECLARE VARIABLE l_data_type  VARCHAR( 50 );

BEGIN

  l_old_table_name = 'T2';
  l_new_table_name  = 'T3';

  l_stm = 'CREATE TABLE ' || l_new_table_name || ' ( ';

  FOR SELECT column_name, data_type
      FROM all_tab_columns
      WHERE table_name = :l_old_table_name
      INTO :l_field_name, :l_data_type
  DO BEGIN
  /* вот здесь !!! */ 
    l_stm = l_stm || :l_field_name || ' ' || :l_data_type || ', ' ;
  END
  l_stm = l_stm || ' )' ;
  EXECUTE STATEMENT l_stm;

END

 /* View: ALL_TAB_COLUMNS */ 
CREATE VIEW ALL_TAB_COLUMNS(
    OWNER,
    TABLE_NAME,
    COLUMN_NAME,
    DATA_TYPE,
    DATA_LENGTH,
    DATA_SCALE)
AS
SELECT r.rdb$owner_name, 
       r.rdb$relation_name, 
       rf.rdb$field_name,
       t.rdb$type_name, 
       f.rdb$field_length, 
       f.rdb$field_scale 
FROM rdb$relations r, 
     rdb$relation_fields rf,
     rdb$fields f, 
     rdb$types t
WHERE r.rdb$relation_name = rf.rdb$relation_name AND
      rf.rdb$field_source = f.rdb$field_name AND
      f.rdb$field_type = t.rdb$type AND 
      t.rdb$field_name = 'RDB$FIELD_TYPE';