The Update method of JDBC

Create 4 classes: Stuinfo (entity Class), Dbconn (connect, close database), Dbutil (Database Operations), Runmain (test Class)

1.StuInfo Entity classes:

Package com.lykion;
	public class Stuinfo {private String sno;
	Private String sname;
	Private String dname;
	Private String Ssex;
	private int cno;
	Private double mark; 
	
	Private String type; Public Stuinfo () {} public Stuinfo (String sno, String sname, String dname, string ssex, int cno, double mark, Stri
		ng type) {super ();
		This.sno = Sno;
		This.sname = sname;
		This.dname = dname;
		This.ssex = Ssex;
		This.cno = CNO;
		This.mark = Mark;
	This.type = type;
	Public String Getsno () {return sno;
	} public void Setsno (String sno) {This.sno = sno;
	Public String Getsname () {return sname;
	} public void Setsname (String sname) {this.sname = sname;
	Public String Getdname () {return dname;
	} public void Setdname (String dname) {this.dname = dname;
	Public String Getssex () {return ssex;
	} public void Setssex (String ssex) {this.ssex = Ssex;
	public int Getcno () {return CNO; } public void Setcno (int cno) {This.cno = CNO;
	Public double Getmark () {return mark;
	public void Setmark (double mark) {This.mark = Mark;
	Public String GetType () {return type;
	public void SetType (String type) {this.type = type;
 }
}

2.DBConn class, operations on the database: Open the database (connect to the database), close the database after the operation completes, release the resources

Package com.lykion;
Import java.sql.Connection;
Import Java.sql.DriverManager;

Import java.sql.SQLException;		public class Dbconn {private static final String URL = "Jdbc:mysql://localhost:3306/test";		Database address private static final String username = "root";		Database user name private static final String password = "123456";		Database Password private static final String Driver = "Com.mysql.jdbc.Driver";
	
	MySQL driver private static final Connection conn = null;
		/** * Connection Database * @return/public static Connection conn () {Connection conn = null;  try {class.forname (driver);  Load Database Drive try {conn = drivermanager.getconnection (URL, username, password);
			Connection database} catch (SQLException e) {e.printstacktrace ();
		} catch (ClassNotFoundException e) {e.printstacktrace ();
	Return conn;  /** * Closes the database link * @return/public static void close () {if (conn!= null) {try {conn.close ();
	Close Database link} catch (SQLException e) {e.printstacktrace ();		}
		}
	}
}
 

3.DBUtil class: Mainly used in data operations, the main example is to implement the update operation

Package com.lykion;
Import java.sql.Connection;
Import java.sql.PreparedStatement;
Import Java.sql.ResultSet;

Import java.sql.SQLException;
	public class Dbutil {private static Connection conn = null;
	private static PreparedStatement PS = null;
	
	private static ResultSet rs = null;		public static void Update (Stuinfo stu) {conn = Dbconn.conn (); Invoke the Conn () method of the DbConnection class to connect to the database String sql = UPDATE student01 SET sname=?, Dname=, ssex=, cno=?		WHERE sno=? ";
			
			SQL statement try {PS = conn.preparestatement (SQL); /** * Sno Modified (updated) Student information according to school number * 1. The position of the incoming parameter will change. * 2.sno position is not in the first position, but at the end * 3. Set the position of each field exactly * * * ps.setstring (1
			, Stu.getsname ());
			Ps.setstring (2, Stu.getdname ());
			Ps.setstring (3, Stu.getssex ());
			Ps.setint (4, Stu.getcno ());
			Ps.setdouble (5, Stu.getmark ());
			Ps.setstring (6, Stu.gettype ());
			
			Ps.setstring (7, Stu.getsno ());
			
			Ps.executeupdate ();
		SYSTEM.OUT.PRINTLN ("Modification succeeds (*￣︶￣)"); catch (SQLException e) {SyStem.out.println ("Operation failed O (╥﹏╥)");
		E.printstacktrace ();
		}finally {dbconn.close ();
 }
	}
}

4.RunMain class: Test class, test whether the method in Dbutil is implemented

Package com.lykion;

public class Runmain {public

	static void Main (string[] args) {
		stuinfo stu = new Stuinfo ("9006", "glutinous rice dumpling", "Computer Science and soft Piece works "," female ", 7, 89," elective ");
		Dbutil.update (stu);	}