java - 更新我的表时出错

Question

我在更新 takeOutTbl 中的记录时遇到错误(只有几条记录)。任何帮助将不胜感激。这是更新代码:

fine = overdueDays * 10; //the fine is calculated by multiplying the number of overdue days by the 10
            simpleUpdate("update takenOutTbl set Random Calculations = Random Calculations " + fine);

它连接到这个方法:

public static void simpleUpdate(String update) throws SQLException {
    try {
        Connection connection = dc.DatabaseConnection(); //a connection to the database is established
        PreparedStatement statement = connection.prepareStatement(update); //the conenction is used to prepare the update statement which was sent to this method
        statement.executeUpdate();//the statement is executed
        statement.close(); //the prepared statement is closed
    } catch (SQLException e) {
        JOptionPane.showMessageDialog(null, "Error: the database was not updated. Please try again." );
        System.err.print(e.getMessage());
    }
}     

我收到的错误消息是这样的:

user lacks privilege or object not found: RANDOM

Answer 1

更正您的查询，如下所示:

"update takenOutTbl set [Random Calculations] = [Random Calculations] + " + fine

由于列名称中存在空格，您必须稍微帮助 MS Access 并指出随机计算 是一列。您可以通过将列名称括在方括号中来完成此操作。

此外，您的查询末尾缺少 +，因此我也在上面的示例中添加了它。