public void addForeignKey(List<SQLForeignKey> foreignKeyCols)
    throws HiveException, NoSuchObjectException {
    try {
      getMSC().addForeignKey(foreignKeyCols);
    } catch (Exception e) {
      throw new HiveException(e);
    }
  }
Get Default constraints associated with the table that are enabled

@param dbName Database Name
@param tblName Table Name
@return Default constraints associated with the table.
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java