JDBC Basic Learning (i) first JDBC sample code

To create a JDBC application:

We take the Mylibray authors table in the MySQL authoritative guide as an example

Here are six steps to build a JDBC application:

• Import the packet. You need to include packages that contain JDBC classes that require database programming. In most cases, you can use the import java.sql.*

• Register the JDBC driver. You need to initialize the driver to open a communication channel with the database

• Open the connection. You need to use the Drivermanager.getconnection () method to create a connection object that represents the physical connection to the database

• Executes the query. You need to create and submit an SQL statement to the database using the type Declaration object

• Extracts data from the result set. Requires appropriate data about the Resultset.getxxx () method to retrieve the result set

• Clean up the environment. Need to explicitly shut down all database resources relative to the JVM's garbage collection

 PackageJdbcdemo;ImportJava.sql.*; Public classFirstexample {//JDBC driver name and database address   Static FinalString jdbc_driver = "Com.mysql.jdbc.Driver"; Static FinalString Db_url = "Jdbc:mysql://localhost/mylibrary"; //Database Login Verification   Static FinalString USER = "root"; Static FinalString PASS = "123456";  Public Static voidMain (string[] args) {Connection conn=NULL; Statement stmt=NULL; Try{      //STEP 2: Register database driverClass.forName ("Com.mysql.jdbc.Driver"); //STEP 3: Open the connectionSYSTEM.OUT.PRINTLN ("Connect database ..."); Conn=drivermanager.getconnection (Db_url,user,pass); //Step 4: Execute a querySYSTEM.OUT.PRINTLN ("Create statement ..."); stmt=conn.createstatement ();      String SQL; SQL= "Select Authid,authname,ts from Authors"; ResultSet RS=stmt.executequery (SQL); //STEP 5: Extracting data from the result set       while(Rs.next ()) {//get data based on column name         intid = rs.getint ("AuthID"); String AuthName= Rs.getstring ("AuthName"); String TS= rs.getstring ("ts"); //Show DataSystem.out.print ("ID:" +ID); System.out.print (", AuthName:" +authname); System.out.print (", TS:" +ts);      System.out.println (); }      //STEP 6: Clean up the environmentRs.close ();      Stmt.close ();   Conn.close (); }Catch(SQLException se) {//Handling JDBC ExceptionsSe.printstacktrace (); }Catch(Exception e) {//handling Class.foname () ExceptionsE.printstacktrace (); }finally{      //The finally block is responsible for closing the resource      Try{         if(stmt!=NULL) Stmt.close (); }Catch(SQLException se2) {}Try{         if(conn!=NULL) Conn.close (); }Catch(SQLException se) {se.printstacktrace (); }} System.out.println ("Good-bye!");}}

Code

JDBC Basic Learning (i) first JDBC sample code