JAVA连接MYSQL,查询 ,添加,删除,语句

package
com;

import
java.sql.*;

/** *//**

* @author Administrator

*/

public class
ggg {

private
Connection con = null
;

private
Statement stmt = null
;

private
String url = "jdbc:mysql://localhost/test
";

private
String user = "root
";

private
String pwd = "0429
";

/** *//** Creates a new instance of Operation */

public
ggg() {

init();

}

/** *//** init */

private void init(){

try {

Class.forName("com.mysql.jdbc.Driver
").newInstance();

con
= DriverManager.getConnection(url
,user
,pwd
);

stmt
= con
.createStatement();

} catch
(Exception e){

// your installation of JDBC Driver Failed

e.printStackTrace();

}

}

/** *//**

* TODO 增加一条记录

* @param sn 学生名字

* @param ss 学生性别

* @param sa 学生年龄

* @param so 学生专业

* @return void

*/

public void
add(String sn,String ss,String sa,String so){

String sql2 = "insert into student value
('"

+sn+"','
"+ss+"','
"+sa+"',`
"+so+"`
);
";

try
{

stmt.execute(sql2);

}catch
(SQLException e){

e.printStackTrace();

}

}

/** *//**

* TODO 查询记录

* @param sn 记录的学生姓名

* @return String 查询的结果

*/

public
String search(String sn){

String str = "so ：sa
："+sn+" ss
：";

String sql1 = "select * from student where sn=
'"+sn+"';
";

try
{

ResultSet rs = stmt
.executeQuery(sql1);

if(rs.next()){

str = str+rs.getString("sn
")+" 手机号
："

+rs.getString("sa
");

}else
str = "该记录不存在
！！！";

}catch
(Exception e){

e.printStackTrace();

}

return
str;

}

/** *//**

* TODO 修改记录

* @param sn 学生姓名

* @param ss 该学生性别

* @parame sa 学生的年龄

* @return void

*/

public
void
modify(String sn,String ss){

String sql = "update sturesult set ss
="+ss

+" where sn
='"+sn+"'
";

try
{

stmt
.executeUpdate(sql);

}catch
(SQLException e){

e.printStackTrace();

}

}

/** *//**

* TODO 删除记录

* @param sn 学生姓名

* @return void

*/

public void
delete(String sn){

String sql1 = "delete from teststudent
"+" where sn=
'"+sn+"';
";

try
{

stmt.executeUpdate(sql1);

}catch
(Exception e){

e.printStackTrace();

}

}

/**关闭连接*/

public void
close(){

try
{

if
(con
!= null
) con
.close();

if
(stmt
!= null
) stmt
.close();

}catch
(Exception e){

e.printStackTrace();

}

}

public static void
main(String args[])throws
Exception{

//add test here!!!!

System.out
.println("ghost is a big worry
");

}

}