databasebean.java

来自「JDBC数据库高级编程源代码」· Java 代码 · 共 54 行

package jdbcbook.msgboard;

import java.sql.*;

/**
 * 数据库处理Bean
 */
public class DatabaseBean
{
	// 取得一个数据库的连接
	public static Connection getConnection( ) throws SQLException
	{
		return jdbcbook.pub.db.DatabaseBean.getConnection( "jdbc/jdbcbook/msgboard" );
	}

	// 取得某个表中可应用的主键
	public static int getMaxID( String tablename ) throws SQLException
	{
		Connection conn = getConnection( );
		int nMaxID = jdbcbook.pub.db.DatabaseBean.getMaxID( conn, tablename );
		conn.close();
		return nMaxID;
	}

	// 关闭连接，释放资源
	public static void close( ResultSet rs, Statement st, Connection conn )
	{
		jdbcbook.pub.db.DatabaseBean.close( rs, st, conn );
	}

	// 执行一个更新数据库的SQL语句
	public static boolean update( String sql )
	{
		Connection conn = null;
		Statement st = null;
		try
		{
			conn 	= DatabaseBean.getConnection();
			st 		= conn.createStatement();
			int nResult = st.executeUpdate( sql );
			return nResult == 1;
		}
		catch( SQLException ex )
		{
			ex.printStackTrace( System.err );
			return false;
		}
		finally
		{
			DatabaseBean.close( null, st, conn );
		}
	}
}