MyEclipse Basic Introduction to MySQL database connection via JDBC

Reprinted from: http://www.jb51.net/article/31876.htm

1. If MyEclipse has been able to develop the Java project normally
2. Install MySQL
The individual is using the version is Mysql-5.0.22-win32.zip
Website: http://www.mysql.com/downloads/mysql/#downloads
3. Download the JDBC driver
Personal use of the mysql-connector-java-5.1.22.zip, what is needed is the Mysql-connector-java-5.1.22-bin.jar after decompression
Website: http://www.mysql.com/downloads/connector/j/

4. Code Testing  

1 Package Ts.jsj.lyh;2 3Import java.sql.*;4 5 /** */6 /**7 * Use JDBC to connect to the database MySQL process DATABASE:JSJ, table:student;8  * 9 * @author DuchangfengTen  */ One  Public classJdbctest { A  -      Public StaticConnection getconnection () throws SQLException, - java.lang.ClassNotFoundException { the         //first step: Load MySQL's JDBC driver -Class.forName ("Com.mysql.jdbc.Driver"); -  -         //get the URL of the connection, can access the MySQL database user name, password; JSJ: Database name +String URL ="Jdbc:mysql://localhost:3306/mydata"; -String username ="Root"; +String Password =""; A  at         //Step Two: Create an instance of the connection class with the MySQL database -Connection con =drivermanager.getconnection (URL, username, password); -         returncon; -     } -  -      Public Static voidMain (String args[]) { in         Try { -             //Step Three: Get the connection class instance con, create an instance of the statement object class with Con sql_statement toConnection con =getconnection (); +Statement sql_statement =con.createstatement (); -  the             /** */ *             /************ related operations to the database ************/ $             //if a database with the same name exists, deletePanax Notoginseng             //sql_statement.executeupdate ("drop table if exists student"); -             //An SQL statement was executed to generate a table named student the             //sql_statement.executeupdate ("CREATE TABLE student (ID int not NULL auto_increment, name varchar () = NOT NULL default ' Name ', math int not NULL default, primary key (ID)); "); +             //inserting data into a table A             //sql_statement.executeupdate ("Insert student values (1, ' liying ', 98)"); the             //sql_statement.executeupdate ("Insert student values (2, ' Jiangshan ',") "); +             //sql_statement.executeupdate ("Insert student values (3, ' Wangjiawu ',") "); -             //sql_statement.executeupdate ("Insert student values (4, ' Duchangfeng ',") "); $             //---above is not practical, but is listed as a reference--- $  -             //Fourth Step: Execute the query, with the object of the ResultSet class, return the results of the query -String query ="SELECT * FROM Student"; theResultSet result =sql_statement.executequery (query); -             /** */Wuyi             /************ related operations to the database ************/ the  -System. out. println ("the data in the student table is as follows:"); WuSystem. out. println ("------------------------"); -System. out. println ("School Number"+" "+"name"+" "+"Data Score"); AboutSystem. out. println ("------------------------"); $  -             //processes the resulting query results and operates on the object of the result class -              while(Result.next ()) { -                 intNumber = Result.getint ("Sno"); AString name = Result.getstring ("sname"); +String Mathscore = result.getstring ("Sgrade"); the                 //get data from the database -System. out. println (" "+ number +" "+ name +" "+mathscore); $             } the  the             //closing connections and claims the sql_statement.close (); the con.close (); -  in}Catch(java.lang.ClassNotFoundException e) { the             //a JDBC error was loaded and the driver used was not found theSystem.err.print ("classnotfoundexception"); About             //Other Errors the System.err.println (E.getmessage ()); the}Catch(SQLException ex) { the             //Display database connection errors or query errors +System.err.println ("SQLException:"+ex.getmessage ()); -         } the     }Bayi  the}

Add a few points that you personally think you need to be aware of:

1) about the storage location of the Mysql-connector-java-5.1.22-bin.jar. Create a new folder for the jar package (such as Lib) in MyEclipse specific Java project, copy the Mysql-connector-java-5.1.22-bin.jar into the folder, select the Jar package right-click--->build Path--->add to Build path.

If it appears 

Classnotfoundexceptioncom.mysql.jdbc.driver 

is the result of a missing import jar package.  

2) If you are already familiar with MySQL usage, you can ignore this one. When the individual is testing the connection, the exception prompt always appears:  

Sqlexception:communications Link failure< Span class= "Apple-converted-space" >&NBSP;
the last packet sent successfully to the server was 0 milliseconds ago. The driver has no received any packets from the server. &NBSP;

This is because the individual is not familiar with MySQL, a lot of attempts to MySQL, I do not know when inadvertently the MySQL service ( If there is no change when installing MySQL, the default service name is MySQL) shutdown, the workaround is to open the service. Control Panel---> Administrative Tools---> Services--->mysql---> select Enabled. &NBSP;

3) when using the above code test, the place to be changed is: //mysql database user name, password, database name &NBSP;

1 " JDBC:MYSQL://LOCALHOST:3306/JSJ "  2"root"3"111" 

and the name of the field in the underlying table that you want to query:

1 int number = Result.getint ("Sno"2 String name = Result.getstring ("sname"3 String mathscore = result.getstring ( " Sgrade "

MyEclipse Basic Introduction to MySQL database connection via JDBC