通过JDBC查询数据库中的数据

package T3;

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

public class StudentJDBCDemo {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
StudentJDBCDemo demo = new StudentJDBCDemo();
Student student = demo.findStudentById(3);
System.out.println(student.toString());
}

// 通过id查询学生
public Student findStudentById(int id) throws ClassNotFoundException, SQLException {
// 1.注册数据库驱动
Class.forName("com.mysql.cj.jdbc.Driver");
// 2.与数据库建立连接
Connection conn = DriverManager.getConnection(
"jdbc:mysql://@localhost:3306/student", "root", "123456");
// 3.创建用来执行SQL语句的Statement对象
Statement stmt = conn.createStatement();
// 4.执行SQL语句
String sql = "select id,name,sno,sex,birthday,cno"+
" from t_student"+
" where id="+id;
ResultSet rs = stmt.executeQuery(sql);
// 5.处理结果集
Student student = null;
if(rs.next()) {
student = new Student(
rs.getInt(1),
rs.getString(2),
rs.getInt(3),
rs.getInt(4),
rs.getDate(5),
rs.getInt(6));
}
// 6.释放资源
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
return student;
}
}

转载于:https://www.cnblogs.com/alpha-cat/p/11394256.html