JDBC实现简单的增删查改

简单的增删查改"/>

JDBC实现简单的增删查改

// 1. 查询tb_user这张表中的数据
public static void printAllUser(){

    try {// (1) 注册驱动Class.forName("com.mysql.jdbc.Driver");// (2) 创建数据库连接Connection conn = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/db_java1ssm?useSSL=true&characterEncoding=utf8", "root", "123456");System.out.println("数据库连接成功!");// (3) 定义sql语句String sql = "select * from tb_user";// (4) 获取执行sql的对象PreparedStatement pstm = conn.prepareStatement(sql);// (5) 执行sqlResultSet rs = pstm.executeQuery();// (6) 遍历结果集while(rs.next()){System.out.println("用户编号:"+rs.getInt(1)+",用户名称:"+rs.getString(2)+",用户密码:"+rs.getString(3)+",用户类型:"+rs.getInt(4));}// (7) 关闭连接rs.close();pstm.close();conn.close();} catch (Exception e) {e.printStackTrace();}finally {}
}
2.//利用sql语句删除，增加和修改操作和本操作类似，只需改变sql语句

public static void main(String[] args) {
Connection conn = null;
PreparedStatement pstmt = null;
try {
Class.forName(“com.mysql.cj.jdbc.Driver”);
conn= DriverManager.getConnection(“jdbc:mysql://localhost:3306/midsoft?&useSSL=false&serverTimezone=UTC”,“root”,“123”);
String sql=“DELETE from tb_user where uid =2”;
pstmt=conn.prepareStatement(sql);
pstmt.executeUpdate();
pstmt.close();
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}