Connect to the mysql database in JAVA and javamysql Database

Connect to the mysql database in JAVA and javamysql Database

Last week, I designed the database course, using java and mysql databases, which involves the knowledge of connecting to the database using java.

package entity;public class user {    private int id;    private String user;    private String pwd;    private String mark;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getUser() {        return user;    }    public void setUser(String user) {        this.user = user;    }    public String getPwd() {        return pwd;    }    public void setPwd(String pwd) {        this.pwd = pwd;    }    public String getMark() {        return mark;    }    public void setMark(String mark) {        this.mark = mark;    }}

Public int addUser (user u) {List <user> list = new ArrayList <user> (); Connection ct = null; PreparedStatement ps = null; ResultSet rs = null; int result = 0; try {Statement sta = null; Class. forName ("com. mysql. jdbc. driver "); ct = DriverManager. getConnection ("jdbc: mysql: // 127.0.0.1: 3306/whj", "root", ""); // connect to the database String SQL = "insert into user (user, pwd, mark) values ('"+ u. getUser () + "','" + u. getPwd () + "','" + u. getMark () + "')"; // Insert new user sta = ct. createStatement (); result = sta.exe cuteUpdate (SQL);} catch (Exception e) {e. printStackTrace ();} return result ;}

Query:

Public int getUser (user u) {List <user> list = new ArrayList <user> (); Connection ct = null; PreparedStatement ps = null; ResultSet rs = null; try {Statement sta = null; Class. forName ("com. mysql. jdbc. driver "); // load the Driver ct = DriverManager. getConnection ("jdbc: mysql: // 127.0.0.1: 3306/whj", "root", ""); // connect to the database String SQL = "select * from user "; // query all user ps = (PreparedStatement) ct. prepareStatement (SQL); rs = ps.exe cuteQuery (); while (rs. next () {user use = new user (); use. setId (rs. getInt ("id"); use. setUser (rs. getString ("user"); use. setPwd (rs. getString ("pwd"); use. setMark (rs. getString ("mark"); list. add (use) ;}for (int I = 0; I <list. size (); I ++) {user use = list. get (I); if (use. getUser (). equals (u. getUser () // verify and Judge & use. getPwd (). equals (u. getPwd () {return 0;} if (I = list. size ()-1) {return-1 ;}} ct. close ();} catch (Exception e) {e. printStackTrace ();} return-1 ;}

Then this is some basic operations for connecting to the database in java.