1.創建一個數據庫一會用來連接
2.使用idea新建一個Java項目
3.在pom文件中加上相關依賴,并配置Maven路徑
<dependencies><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.29</version></dependency>
</dependencies>
新建jdbcdemo包和其中的類
package com.qcby.jdbcdemo;import com.mysql.jdbc.Driver;import java.sql.*;public class JdbcDemo {//主方法 主函數 程序入口public static void main(String[] args) {ResultSet resultSet = null;Statement statement = null;Connection connection = null;try {//1,加載驅動 2種 反射加載 直接加載//Class.forName("com.mysql.jdbc.Driver");DriverManager.registerDriver(new Driver());//2,獲取連接 4個 用戶名 密碼 url//jdbc:mysql://localhost:3306/test 主協議 二層協議 mysql IP地址 端口號 127.0.0.1:3306connection = DriverManager.getConnection("jdbc:mysql:///jdbctest","root","123456");//3,編寫sqlString sql = "select * from student";//4,獲取執行sql的對象 2種 不安全 sql注入問題 preparedStatementstatement = connection.createStatement();//5,執行sql 拿到結果集resultSet = statement.executeQuery(sql);//6,遍歷結果集while (resultSet.next()){Student student = new Student();student.setId(resultSet.getInt("id"));student.setName(resultSet.getString("name"));student.setAge(resultSet.getInt("age"));student.setSex(resultSet.getString("sex"));System.out.println(student);}}catch (Exception e) {throw new RuntimeException(e);}finally {//永遠執行//7,關閉資源try {resultSet.close();statement.close();connection.close();} catch (Exception e) {throw new RuntimeException(e);}}}
}
package com.qcby.jdbcdemo;public class Student {private Integer id;private String name;private Integer age;private String sex;public Student() {}public Student(Integer id, String name, Integer age, String sex) {this.id = id;this.name = name;this.age = age;this.sex = sex;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}@Overridepublic String toString() {return "Student{" +"id=" + id +", name='" + name + '\'' +", age=" + age +", sex='" + sex + '\'' +'}';}
}
然后運行,就可以從數據庫中讀取數據了