SQL 连接：无法连接到 java 中的数据库

Question

我添加了 JAR 文件 "mysql-connector-java-5.1.36-bin" 并创建了数据库 "UserScore" 并在 table "ScoreSheet" 下创建了数据库。我在 ScoreSheet (Name,Score) 中添加了一行值 ('Kamal',40) 进行验证，但代码在 connection.I 上抛出很多异常，我正在使用 Eclipse + Xampp.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class SQLDriver{
    public static void main(String[] args){
        try{
            //Accessing driver from jar file
            Class.forName("com.mysql.jdbc.Driver");

            //Get connection through creating a variable 'myConn'
            Connection myConn = DriverManager.getConnection("jdbc:mysql://localhost:3306/UserScores");

            //Create statement
            PreparedStatement statement = myConn.prepareStatement("select * from 'scoresheet'");

            //Execute SQL Query
            ResultSet result = statement.executeQuery();

            //Process the result set
            while(result.next()){
                System.out.println(result.getString(1)+" "+result.getString(2));
            }
        }
        catch(Exception e){
            e.printStackTrace();
        }
    }
}

Answer 1

您的查询应该指定 Scoresheet 而没有 '
调用时指定用户名和密码DriverManager.getConnection
您 table 中的第二行似乎不是字符串类型。调用 result.getInt(2) 而不是 result.getString(2)

Answer 2

我总是这样做：

// Hostname
private static final String dbHost = "127.0.0.1";

// Port -- Standard: 3306
private static final String dbPort = "3306";

// Database name
private static String database = "database"; //

// Database user
private static final String dbUser = "root";

// Datenbankpasswort
private static final String dbPassword = "";

private Statement s;


public void Connect() {
    try {
        Class.forName("java.sql.Driver"); // load driver
        Connection conn = DriverManager.getConnection("jdbc:mysql://" + dbHost + ":"
                + dbPort + "/" + database + "?" + "user=" + dbUser + "&"
                + "password=" + dbPassword); // try to connect with your attributes 
        s = conn.createStatement();
    } catch (ClassNotFoundException e) { // 
        l.error("Driver not found " + e);
    } catch (SQLException e) {
        l.error("Connect not possible" + e);
    }
}

SQL 连接：无法连接到 java 中的数据库

SQL connection : can't connect to database in java

java

mysql

jdbc

xampp

database-connection