net.ucanaccess.jdbc.UcanaccessSQLException: Column

问题:

I am new for UCanAccess

package checktpsystemdatabase;

import java.sql.*;

public class CheckTPSystemDatabase {

    public static void main(String[] args) throws SQLException {
        try {
            Connection con = DriverManager.getConnection("jdbc:ucanaccess://D:/Java/TransactionProcessingSystem/src/transactionprocessingsystem/Resources/TPSystem.accdb");

            Statement stmt = con.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM Product");

            while (rs.next()) {
                System.out.println(rs.getInt(0) + "\t" + rs.getString(1) + "\t" + rs.getString(2));
            }
            rs.close();

        } catch (SQLException e) {
            System.out.println(e);
        }
    }
}

When I execute this code, It is showing "net.ucanaccess.jdbc.UcanaccessSQLException: Column not found: 0". Please help me!

回答1:

You are seeing that error because the numeric index values for a JDBC ResultSet start with 1, not 0. Or, as they say in the "Retrieving Column Values from Rows" section of the Java Tutorial here:

The ResultSet interface declares getter methods (for example, getBoolean and getLong) for retrieving column values from the current row. You can retrieve values using either the index number of the column or the alias or name of the column. The column index is usually more efficient. Columns are numbered from 1

(Emphasis mine.)

回答2:

simply

the ResultSet rs begins with index 1 not 0 so you should write rs.getInt(1) or rs.getObject(1)