Java+MySQL with JDBC connector错误

Question

我正在尝试使用 JDBC 连接器连接 Java 和 MySQL。所以，我从 official cite 下载了连接器，将其添加到类路径并添加到 eclipse 的库中。现在我正在使用下面的代码

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


    public class LocalhostDBConnection 
    {   
        LocalhostDBConnection()
        {
        Connection connection;
        try {
            // Название драйвера
            String driverName = "com.mysql.jdbc.Driver"; 

            Class.forName(driverName);

            // Create a connection to the database
            String serverName = "localhost";
            String mydatabase = "AvtoKovriki";
            String url = "jdbc:mysql://" + serverName + "/" + mydatabase;
            String username = "root";
            String password = "";

            connection = DriverManager.getConnection(url, username, password);
            System.out.println("is connect to DB" + connection);

            String query = "Select * FROM users";
            Statement stmt = connection.createStatement();

            ResultSet rs = stmt.execute(query);
            String dbtime;
            while (rs.next()) 
            {
                dbtime = rs.getString(1);
                System.out.println(dbtime);
            } // end while

            connection.close();
        } // end try
        catch (ClassNotFoundException e) 
        {
            e.printStackTrace();
            // Could not find the database driver
        } catch (SQLException e) 
        {
            e.printStackTrace();
            // Could not connect to the database
        }
        }
    }

但在字符串中:ResultSet rs = stmt.execute(query);出现错误“类型不匹配:无法从 boolean 值转换为 ResultSet”。我不明白问题出在哪里。需要一些帮助。

Answer 1

Statement#execute方法返回一个 boolean。您正在寻找 Statement#executeQuery方法，它返回一个 ResultSet。

你的代码应该是这样的:

ResultSet rs = stmt.executeQuery(query);