尚硅谷之JDBC

         //通用的更新数据库的方法：insert,update,delete语句时

         public static int update(String sql)throws SQLException{

                   //1、获取连接

                   Connection conn = JDBCUtils.getConnection();

                   //2、获取Statement对象，这个对象是用来给服务器传sql并执行sql

                   Statement st = conn.createStatement();

                   //3、执行sql

                   int len = st.executeUpdate(sql);

                   //4、释放资源

                   JDBCUtils.closeQuietly(st, conn);

                   return len;

         }

         //      通用的更新数据库的方法：insert,update,delete语句，允许sql带?

         public static int update(String sql, Object... args)throws SQLException{

                   Connection conn = JDBCUtils.getConnection();

                   int len = update(conn,sql,args);

                   JDBCUtils.closeQuietly(conn);

                   return len;

         }

         //      通用的更新数据库的方法：insert,update,delete语句，允许sql带?

         public static int update(Connection conn, String sql, Object... args)throws SQLException{

                   //2、获取PreparedStatement对象，这个对象是用来sql进行预编译

                   PreparedStatement pst = conn.prepareStatement(sql);

                   //3、设置sql中的?

                   if(args!=null && args.length>0){

                            //数组的下标是从0开始，？的编号是1开始

                            for (int i = 0; i < args.length; i++) {

                                     pst.setObject(i+1, args[i]);

                            }

                   }

                   //4、执行sql

                   int len = pst.executeUpdate();

                   //5、释放资源

                   JDBCUtils.closeQuietly(pst);

                   return len;

         }