一、下载驱动
下载MySQL的驱动包，然后将包导入到集成开发环境中
二、加载驱动
导入包之后，通过语句加载驱动
Class.forName("com.mysql.jdbc.Driver");三、建立连接
DriverManger类提供了两种用于建立连接的类方法（static方法）
Connection getConnection(java.lang.String,java.lang.String,java.lang.String);
Connection getConnection(java.lang.String);这两个方法都可能抛出SQL Exception异常，都返回一个Connection对象
如下：
String url="jdbc:mysql://localhost:3306/student?useSSL=false&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true";
String user="root";
String password="12345";
Connection conn=DriverManager.getConnection(url,user,password);四、实际项目
1.JDBC.java
import java.sql.*;
public class JDBC {
private Statement stmt = null;
private Connection conn= null;
ResultSet rs = null;
public JDBC() {
}
// 数据库连接函数
public void openConnection() {
try {
// 连接数据库
// 加载驱动
Class.forName("com.mysql.jdbc.Driver").newInstance();
String url="jdbc:mysql://localhost:3306/books?useSSL=false&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true";
String user="root";
String password="12345";
// 连接数据库
conn=DriverManager.getConnection(url,user,password);
} catch (Exception e) {
e.printStackTrace();
}
}
// 数据库查询函数
public ResultSet executeQuery(String sql) {
rs = null;
try {
// 执行数据库查询语句，通过外界传入sql语句
stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
rs=stmt.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
// 查询成功返回一个集合
return rs;
}
// 数据库更新函数
public int executeUpdate(String sql) {
int n =0;
try {
stmt=conn.createStatement();
n=stmt.executeUpdate(sql);
} catch (Exception e) {
e.printStackTrace();
}
return n;
}
// 数据库关闭函数
// 运行完数据库要关闭所有连接,减少内存压力
public void closeConnection() {
try {
if (rs!=null) {
rs.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
if (stmt!=null) {
stmt.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
if (conn!=null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
2.mian.java
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;
public class main {
public static void main(String[] args) {
JDBC jdbc = new JDBC();
int i=0;
System.out.println("欢迎来到图书系统！");
while (i!=5) {
System.out.println("目录：");
System.out.println("1.查询所有图书；");
System.out.println("2.增加图书；");
System.out.println("3.删除图书；");
System.out.println("4.查询图书；");
System.out.println("5.退出；");
System.out.println("请选择：");
Scanner ready = new Scanner(System.in);
i = ready.nextInt();
if (i==1){
// 定义查询sql语句
String sql1="select * from book_message";
jdbc.openConnection();
ResultSet rs=jdbc.executeQuery(sql1);
try {
while (rs.next()){
String name = rs.getString("name");
String zz = rs.getString("zz");
String cbs = rs.getString("cbs");
String date = rs.getString("date");
String jg = rs.getString("jg");
System.out.printf("%s\t",name);
System.out.printf("%s\t",zz);
System.out.printf("%s\t",cbs);
System.out.printf("%s\t",date);
System.out.printf("%s元\n",jg);
}
jdbc.closeConnection();
}catch (Exception e){
e.printStackTrace();
}
}else if (i==2){
// 定义增加图书语句
String sql2="insert into book_message(id,name,zz,cbs,date,jg)";
String id,name,zz,cbs,date,jg;
System.out.println("请输入id：");
id = ready.next();
System.out.println("请输入书名：");
name = ready.next();
System.out.println("请输入作者：");
zz = ready.next();
System.out.println("请输入出版社：");
cbs = ready.next();
System.out.println("请输入时间：");
date = ready.next();
System.out.println("请输入价格：");
jg = ready.next();
sql2=sql2+"values('"+id+"','"+name+"','"+zz+"','"+cbs+"','"+date+"','"+jg+"')";
jdbc.openConnection();
int n = jdbc.executeUpdate(sql2);
if (n>0) System.out.println("添加成功！");
else System.out.println("添加失败！");
jdbc.closeConnection();
}
else if (i==3){
// 定义删除sql语句
String sql3 = "delete from book_message where";
System.out.println("请输入删除图书名：");
String name = ready.next();
sql3 = sql3+" name='"+name+"'";
jdbc.openConnection();
int n = jdbc.executeUpdate(sql3);
if (n>0) System.out.println("删除成功！");
else System.out.println("删除失败！");
jdbc.closeConnection();
}else if (i==4){
// 定义查询sql语句
String sql4 = "select * from book_message where name='";
System.out.println("请输入查询图书名：");
String name = ready.next();
sql4 = sql4+name+"'";
jdbc.openConnection();
try {
ResultSet rs =jdbc.executeQuery(sql4);
rs.next();
String zz = rs.getString("zz");
String cbs = rs.getString("cbs");
String date = rs.getString("date");
String jg = rs.getString("jg");
System.out.printf("%s\t",name);
System.out.printf("%s\t",zz);
System.out.printf("%s\t",cbs);
System.out.printf("%s\t",date);
System.out.printf("%s元\n",jg);
jdbc.closeConnection();
}catch (Exception e){
e.printStackTrace();
}
}
}
System.out.println("欢迎下次使用！");
}
}
五、可能出现问题
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.驱动的版本低，新版的不会出现，下载新的驱动或者修改forName
Class.forName("com.mysql.cj.jdbc.Driver").newInstance();