/**
* Executes the given SQL statement, which returns a single
* <code>ResultSet</code> object.
*
* @param sql an SQL statement to be sent to the database, typically a
* static SQL <code>SELECT</code> statement
* @return a <code>ResultSet</code> object that contains the data produced
* by the given query; never <code>null</code>
* @exception SQLException if a database access error occurs or the given
* SQL statement produces anything other than a single
* <code>ResultSet</code> object
*/
ResultSet executeQuery(String sql) throws SQLException;
/**
* Executes the given SQL statement, which may be an <code>INSERT</code>,
* <code>UPDATE</code>, or <code>DELETE</code> statement or an
* SQL statement that returns nothing, such as an SQL DDL statement.
*
* @param sql an SQL <code>INSERT</code>, <code>UPDATE</code> or
* <code>DELETE</code> statement or an SQL statement that returns nothing
* @return either the row count for <code>INSERT</code>, <code>UPDATE</code>
* or <code>DELETE</code> statements, or <code>0</code> for SQL statements
* that return nothing
* @exception SQLException if a database access error occurs or the given
* SQL statement produces a <code>ResultSet</code> object
*/
int executeUpdate(String sql) throws SQLException;
