Java operation MySQL Database simple example

Package com. Jdbc.demo;

Import Java.sql.DriverManager;

Import Java.sql.ResultSet;

Import java.sql.Statement;

Import com.mysql.jdbc.Connection;

public class Jdbc02 {

public static final String URL = "Jdbc:mysql://localhost:3306/school?useunicode=true&characterencoding=utf-8"; The URL address of the connection database

public static String username = "root"; User name of the database

public static String password = ""; Password for the database

public static Connection conn=null;//Connection object

public static Statement stmt=null;//statement

public static ResultSet rs = null;//result set

1. Load MySQL Database driver

Static

{

try {

Class.forName ("Com.mysql.jdbc.Driver");

2. Establish database connection

conn = (Connection) drivermanager.getconnection (Url,username,password);

IF (conn! = null)

{

SYSTEM.OUT.PRINTLN ("Database connection is OK");

}

Else

{

SYSTEM.OUT.PRINTLN ("Database connection failed");

}

}

catch (Exception e)

{

E.printstacktrace ();

}

}

Query all student Information

public static void query ()

{

String sql = "SELECT * from students;";

try {

stmt = Conn.createstatement ();

rs = stmt.executequery (SQL);

while (Rs.next ())

{

System.out.println ("School Number:" +rs.getint ("Sid") + ", Name:" +rs.getstring ("sname") + ", Age:" +rs.getint ("ages") + ", Gender:" +rs.getstring ("gender"));

}

} catch (Exception e)

{

E.printstacktrace ();

}

finally

{

Destoryresource ();

}

}

Add Student method

public static Boolean Add ()

{

String sql = "INSERT into Students values (11, ' Three days ', 138, ' F ', ' [email protected] ', ' Guangzhou Yangjiang ');";

Try

{

stmt = Conn.createstatement ();

int result = stmt.executeupdate (SQL);

if (Result > 0)

{

SYSTEM.OUT.PRINTLN ("Data added successfully");

return true;

}

Else

{

SYSTEM.OUT.PRINTLN ("Database add failed");

return false;

}

}

catch (Exception ex)

{

Ex.printstacktrace ();

return false;

}

Finally

{

Destoryresource ();

}

}

Ways to release resources

public static void Destoryresource ()

{

try {

if (rs! = null)

{

rs.close ();

rs = null;

}

if (stmt! = null)

{

stmt.close ();

stmt = null;

}

} catch (Exception e) {

Todo:handle exception

E.printstacktrace ();

}

}

//Release last Resource

public static void Destoryallresource ()

{

Try

{

if (conn! = null)

{

Conn.close ();

conn = null;

}

} catch (Exception e) {

Todo:handle exception

E.printstacktrace ();

}

}

Delete the student information of the assigned school number

public static boolean delete (int sid)

{

String sql = "Delete from students where sid=" +SID;

Try

{

stmt = Conn.createstatement ();

int result = stmt.executeupdate (SQL);

if (result>0)

{

SYSTEM.OUT.PRINTLN ("Data deletion succeeded");

return true;

}

Else

{

SYSTEM.OUT.PRINTLN ("Data Tim is not deleted");

return false;

}

}

catch (Exception ex)

{

Ex.printstacktrace ();

return false;

}

Finally

{

Destoryresource ();

}

}

Modification of all students to 20 years of age

public static Boolean update (int age)

{

String sql = "Update students set age=" +age;

Try

{

stmt = Conn.createstatement ();

int result = stmt.executeupdate (SQL);

if (result>0)

{

return true;

}

Else

{

return false;

}

}

catch (Exception ex)

{

ex.printstacktrace ();

return false;

}

finally

{

Destoryresource ();

}

}

public static void Main (string[] args)

{

jdbc02.query (); Query statements

if (Jdbc02.add ())

{

System.out.println ("added successfully! ");

}

Else

{

System.out.println ("Add failed! ");

}

System.out.println ("---------------------");

jdbc02.query ();

Jdbc02.delete (11);

SYSTEM.OUT.PRINTLN ("--------------" after deleting the student number 11);

Jdbc02.query ();

Jdbc02.update (20);

SYSTEM.OUT.PRINTLN ("------Modify all students aged 20 years--------");

Jdbc02.query ();

Jdbc02.destoryallresource (); Freeing resources

}

}

This article is from the "Know the Ming" blog, please be sure to keep this source http://357712148.blog.51cto.com/6440370/1894631

Java operation MySQL Database simple example