MySQL PreparedStatement 方法

 

创建PreparedStatement对象

PreparedStatement preparedStatement = connection.PreparedStatement（sql语句）;

此时sql语句必须写好，不能通过一个变量再进行传入，因为PreparedStatement要做预编译

 

 

 

        PreparedStatement preparedStatement = connection.prepareStatement("select * from lesson where lessonname = ? and lessonteacher = ?");
        preparedStatement.setString(1,"数据结构");
        preparedStatement.setString(2,"刘丹");
        System.out.println(preparedStatement);

当PreparedStatement preparedStatement = connection.prepareStatement("select * from lesson where lessonname = ? and lessonteacher = ?");的括号中有内容时，后面再调用executeUpdate（）或者executeQuery（）的括号中的语句默认为preparedStatement（）括号中的内容。

        PreparedStatement preparedStatement = connection.prepareStatement("select * from lesson where lessonname = ? and lessonteacher = ?");
        preparedStatement.setString(1,"数据结构");
        preparedStatement.setString(2,"刘丹");
        ResultSet resultSet = preparedStatement.executeQuery();
        if(resultSet.next())
        {
            System.out.println("查找成功");
        }