Check if a primary key value is referred in any other table
You can check dba_constraints:

Get the primary key constraint name:

select constraint_name 
from dba_constraints 
where owner = '&lt;SCHEMA_NAME&gt;' and table_name = 'STUDENT' and constraint_type = 'P';


Then check where that constraint is used:

select owner, table_name, constraint_name
from dba_constraints 
where r_constraint_name = '&lt;result from previous query&gt;' and constraint_type = 'R';


To get the column name of the referential constraint, you can use dba_cons_columns:

select owner, table_name, column_name 
from  dba_cons_columns
where constraint_name = '&lt;constraint name from previous query&gt;';


Plugging all of this together, you can do something like:

  SELECT fk.owner, fk.table_name, col.column_name
    FROM dba_constraints pk
    JOIN dba_constraints fk
      ON pk.constraint_name = fk.r_constraint_name
     AND fk.constraint_type = 'R'
    JOIN dba_cons_columns col
      ON fk.constraint_name = col.constraint_name
   WHERE pk.owner = :owner AND pk.table_name = 'STUDENT' AND pk.constraint_type = 'P';