上面两篇讲解了简单的JSP + Servlet的搭建和请求，那么后面我们肯定要用到数据交互，也就是操纵数据库的数据，包括对数字的增加，删除，修改，查询。我们就用简单的MySql来做例子
我们需要引入驱动包mysql-connector-java.jar，自行去网上下载，有很多。
下面我跟着代码看看怎么进行增删改查
1.打开数据库
// 驱动程序名
private String driver = "com.mysql.jdbc.Driver";
// URL指向要访问的数据库名scutcs
private String url = "jdbc:mysql://127.0.0.1:3306/studentdb";
// MySQL配置时的用户名
private String user = "root";
// MySQL配置时的密码
private String password = "root"; private static Connection conn = null; /**
* 打开数据连接
*/
public void openDbConnect()
{
try
{
// 加载驱动程序
Class.forName(driver);
// 连接数据库
if(conn == null || conn.isClosed())
{
conn = DriverManager.getConnection(url, user, password);
}
if(!conn.isClosed())
{
System.out.println("Succeeded connecting to the Database!");
}
}
catch(Exception ex)
{
System.out.println("访问数据库失败");
}
}
2.增加数据
/**
* 插入数据
* @param student
* @throws SQLException
*/
public void insertStudent(Student student) throws SQLException
{
Statement statement = conn.createStatement();
// 要执行的SQL语句
String sql = "insert into student (studentname,age,classname) values('"
+ student.getStudentname() + " ',"
+ student.getAge() + ",'" + student.getClassname() + "')";
statement.execute(sql);
}
3.删除数据
/**
* 删除数据
* @param student
* @throws SQLException
*/
public void deleteStudent(int id) throws SQLException
{
Statement statement = conn.createStatement();
// 要执行的SQL语句
String sql = "delete from student where id = " + id;
statement.execute(sql);
}
4.更新数据
/**
* 修改数据
* @param student
* @throws SQLException
*/
public void updateStudent(Student student) throws SQLException
{
Statement statement = conn.createStatement();
// 要执行的SQL语句
String sql = "update student set ";
// 学生名称
if(student.getStudentname() != null && !student.getStudentname().trim().equals("") )
{
sql += " studentname = '" + student.getStudentname() + "',";
}
// 年龄
if(student.getAge() != 0 )
{
sql += " age = " + student.getAge() + ",";
}
// 年级
if(student.getClassname() != null && !student.getClassname().trim().equals("") )
{
sql += " classname = '" + student.getClassname() + "',";
}
sql = sql.substring(0, sql.length() - 1);
sql = sql + " where id = " + student.getId();
statement.execute(sql);
}
5.查询数据
/**
* 修改数据
* @param student
* @throws SQLException
*/
public void queryStudent(String studentname) throws SQLException
{
Statement statement = conn.createStatement();
// 要执行的SQL语句
String sql = "select * from student where studentname = '" + studentname + "'";
ResultSet rs = statement.executeQuery(sql);
while(rs.next()) {
// 选择sname这列数据
String studentnamers = rs.getString("studentname");
String agers = rs.getString("age");
String classnamers = rs.getString("classname");
// 输出结果
System.out.println("学生名称:" + studentnamers + ",年龄:" + agers + ",班级:" + classnamers);
}
}
以上介绍了JAVA访问Mysql的简单代码，比较深入的后面我们再讲解。本篇文章只是带大家简单入门
结语
- 受益，学会了如何用JAVA访问Mysql数据库
本站文章为宝宝巴士 SD.Team原创，转载务必在明显处注明：（作者官方网站：宝宝巴士)
转载自【宝宝巴士SuperDo团队】 原文链接: http://www.cnblogs.com/superdo/p/4561918.html