public static Table tableIfExists(ImportTableDesc tblDesc, Hive db) throws HiveException {
    try {
      return db.getTable(tblDesc.getDatabaseName(),tblDesc.getTableName());
    } catch (InvalidTableException e) {
      return null;
    }
  }
Utility method that returns a table if one corresponding to the destination
tblDesc is found. Returns null if no such table is found.
ql/src/java/org/apache/hadoop/hive/ql/parse/ImportSemanticAnalyzer.java