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  • java连接数据库,执行增删改查操作


    public class ConnectionDataBaseTest {

    public static final String driver="com.mysql.jdbc.Driver";//驱动
    public static final String url="jdbc:mysql://localhost:3306/ssm";//指向数据库名
    public static final String user="root";//用户
    public static final String password="root";//密码

    public static void main(String[]args){
    try {
    Class.forName(driver);//加载驱动
    Connection connection=DriverManager.getConnection(url,user,password);//创建连接
    queryDataBase(connection);
    } catch (ClassNotFoundException e) {
    e.printStackTrace();
    } catch (SQLException e){
    e.printStackTrace();
    }
    }

    //查询数据
    public static void queryDataBase(Connection connection){
    try {
    String sql="SELECT * FROM user";
    Statement statement=connection.createStatement();
    ResultSet resultSet=statement.executeQuery(sql);

    int id;
    String name=null;
    int age;
    String gender=null;
    while (resultSet.next()){
    id=resultSet.getInt("id");
    name=resultSet.getString("name");
    age=resultSet.getInt("age");
    gender=resultSet.getString("gender");
    System.out.println("id:"+id+";name:"+name+";age:"+age+";gender:"+gender);
    }
    statement.close();
    resultSet.close();
    } catch (SQLException e){
    e.printStackTrace();
    }finally {
    System.out.println("数据查询成功!");
    }
    }

    //插入数据
    public static void insertDataBase(Connection connection){
    try {
    PreparedStatement preparedStatement=
    connection.prepareStatement("INSERT INTO user(id,name,age,gender) VALUES (?,?,?,?)");
    preparedStatement.setInt(1,4);
    preparedStatement.setString(2,"马云");
    preparedStatement.setInt(3,30);
    preparedStatement.setString(4,"男");
    preparedStatement.executeUpdate();//插入,修改和删除数据时都要用excuteUpdate()
    preparedStatement.close();
    } catch (SQLException e){
    e.printStackTrace();
    }
    }

    //修改数据
    public static void updateDataBase(Connection connection){
    try {
    PreparedStatement preparedStatement=connection.prepareStatement("UPDATE user SET name=? WHERE id=?");
    preparedStatement.setString(1,"马化腾");
    preparedStatement.setInt(2,3);
    preparedStatement.executeUpdate();
    preparedStatement.close();
    } catch (SQLException e) {
    e.printStackTrace();
    }
    }

    //删除数据
    public static void deleteDataBase(Connection connection){
    try {
    PreparedStatement preparedStatement=connection.prepareStatement("DELETE FROM user WHERE id=?");
    preparedStatement.setInt(1,2);
    preparedStatement.executeUpdate();
    preparedStatement.close();
    } catch (SQLException e) {
    e.printStackTrace();
    }
    }
    }
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  • 原文地址:https://www.cnblogs.com/lihongjunjava/p/8572351.html
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