JDBC的安装
首先在登录MySQL的官网下载JDBC-MySQL数据库驱动，或者去www.mysql.com/products/connector直接下载。
因为jdbc包属于第三方包，因此要自己导入，下面是导入的方法：
https://jingyan.baidu.com/article/3aed632e1a4ceb70108091f6.html
导入之后就创建一个connect类来编写代码，来测试是否能与服务器连接。
import java.sql.*;//导入sql包
public class connect {
public static void main(String args[]) throws SQLException, ClassNotFoundException
{
//数据库连接
Statement sql;//数据库
ResultSet rs;//数据
Connection conn;//用于连接
String url = "jdbc:mysql://localhost:3306/students?serverTimezone=UTC&useSSL=false";
String username = "root";
String password = "123456";//密码自己修改
//Class.forName("com.mysql.cj.jdbc.Driver");//加载JDBC-MySQL驱动
conn =
DriverManager.getConnection(url,username,password);//连接完毕
try{
Class.forName("com.mysql.cj.jdbc.Driver");//加载JDBC-MySQL驱动
conn = DriverManager.getConnection(url,username,password);
if(conn != null){
System.out.println("数据库连接成功!");
}else{
System.out.println("数据库连接失败！");
}
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}
}}
如果数据库可以连接之后就可以来试一下数据库的基本操作；
import java.sql.*;//导入sql包
public class connect {
public static void main(String args[]) throws SQLException, ClassNotFoundException
{
//数据库连接
Statement sql;//数据库
ResultSet rs;//数据
Connection conn;//用于连接
String url = "jdbc:mysql://localhost:3306/students?serverTimezone=UTC&useSSL=false";
String username = "root";
String password = "123456";//密码
//Class.forName("com.mysql.cj.jdbc.Driver");//加载JDBC-MySQL驱动
conn = DriverManager.getConnection(url,username,password);//连接完毕
//添加筛选条件
String c1 = " year(birthday)<=2000 and month(birthday)>7";
String c2 = " name Like '张_%' ";
String c3 = " height >1.65";
String sqlStr="select * from mess where" +c1+ " and "+c2+ " and "+c3+"order by birthday";
try {
sql = conn.createStatement();
rs = sql.executeQuery(sqlStr);
while(rs.next())
{
String number=rs.getString(1);
String name=rs.getString(2);
Date date =rs.getDate(3);
float height=rs.getFloat(4);
System.out.printf("%s\t",number);
System.out.printf("%s\t",name);
System.out.printf("%s\t",date);
System.out.printf("%.2f\t",height);
System.out.printf("\n");
}
//conn.close();
}
catch(SQLException e)
{
System.out.println(e);
}
System.out.println("--------华丽的分割线---------");
/*try{
Class.forName("com.mysql.cj.jdbc.Driver");//加载JDBC-MySQL驱动
conn = DriverManager.getConnection(url,username,password);
if(conn != null){
System.out.println("数据库连接成功!");
}else{
System.out.println("数据库连接失败！");
}
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}*/
//顺序查询
try {
//conn = DriverManager.getConnection(url,username,password);
sql = conn.createStatement();
rs = sql.executeQuery("SELECT*FROM mess");
while(rs.next()) {
String number=rs.getString(1);
String name=rs.getString(2);
Date date =rs.getDate(3);
float height=rs.getFloat(4);
System.out.printf("%s\t",number);
System.out.printf("%s\t",name);
System.out.printf("%s\t",date);
System.out.printf("%.2f\t",height);
System.out.printf("\n");
}
conn.close();
}
catch(SQLException e)
{
System.out.println(e);
}
}
}
可能会遇到的问题：
JDBC连接MYSQL数据库失败，Loading class `com.mysql.jdbc.Driver'. This is deprecated.
https://blog.csdn.net/weixin_42323802/article/details/82589743