CSC 411/511: DBMS Design Dr. Nan WangCSC411_L12_JDBC_MySQL 1 MySQL and JDBC

CSC 411/511: DBMS Design

Dr. Nan Wang CSC411_L12_JDBC_MySQL1

MySQL and JDBC

CSC411_L12_JDBC_MySQLDr. Nan Wang 2

Web-based database applications

• Online book store• What are needed:

– Web pages– Web server

• Apache– Database– Database server

• MySQL– CGI scripts

• Java serverlet– Connector which enables applications connect to database

• JDBC

2


Web Server

3


Database Server

4


Introduction

• RDBMS– Relational database management system

– MySQL• Open source

• Available for both Windows and Linux

• dev.mysql.com/downloads/mysql/5.0.hml

• JDBC– Java Database Connectivity

– JDBC driver• Enable Java applications to connect to database

• Enable programmers to manipulate databases using JDBC


Instructions to Install MySQL and MySQL Connector/J

• Install MySQL– Insert CD and change directory to D:\software\MySQL\mysql-4.0.20c-win

– Double click SETUP.EXE– Following the instruction

• Install MySQL Connector/J– Copy mysql-connector-java-3.0.14-production.zip– Open mysql-connector-java-3.0.14-production.zip

• Extract its content to the C:\ driv


Instructions on Setting MySQL User Account

• Set up a user account– Start database server by executing the script C:\mysql\bin\mysqld

– Start the MySQL monitor by executing the command C:\mysql\bin>mysql –h localhost –u root

– Create an account mysql> USE mysql;mysql> INSERT INTO user SET Host=‘localhost’,

User=‘jhtp6’, Password=PASSWORD(‘jhtp6’), Select_priv=‘Y’, Insert_priv=‘Y’, Update_priv=‘Y’, Delete_priv=‘Y’, Create_priv=‘Y’, Drop_priv=‘Y’, References_priv=‘Y’, Execute_priv=‘Y’;

mysql> FLUSH PRIVILEGES;mysql> exit;


Creating Database books in MySQL

• Create books database– Open Command Prompt– Change to the C:\mysql\bin directory– Start database by executing the command C:\mysql\bin\mysqld

– Copy SQL script books.sql to C:\mysql\bin directory– Open another Command Prompt– Change to the C:\mysql\bin directory– Create the books database by executing the command C:\

mysql\bin>mysql –h localhost –u jhtp6 –p < books.sql


Relational Databases

• Relational database– Table

• Rows, columns– Primary key

• Unique data

• SQL queries– Specify which data to select from a table

Employee table


Relational Database Overview: The books Database

• Sample books database– Four tables

• authors– authorID, firstName, lastName

• publishers– publisherID, publisherName

• titles– isbn, title, editionNumber, copyright, publisherID,

imageFile, price• authorISBN

– authorID, isbn


Sample Data (author and publisher)

authorID firstName lastName

1 Harvey Deitel

2 Paul Deitel

3 Tem Nieto

4 Sean Santry

publisherID publisherName

1 Prentice Hall

2 Prentice Hall PTG


Sample data (titles and authorISBN) isbn

title

editionNumber

copyright

publisherID

Image File price

0131426443 C How to Program

4 2004 1 chtp4.jpg 85.00

0130384747 C++ How to Program

4 2003 1 cpphtp4.jpg

85.00

0130461342 Java Web Services for Experienced Programmers

1 2003 1 jwsfep1.jpg

54.99

0131483986 Java How to Program

6 2005 1 jhtp6.jpg 85.00

013100252X The Complete C++ Training Course

4 2003 2 cppctc4.jpg

109.99

0130895601 Advanced Java 2 Platform How to Program

1 2002 1 advjhtp1.jpg

69.95

authorID isbn authorID isbn

1 0130895725 2 0139163050

2 0130895725 3 0130829293

2 0132261197 3 0130284173

2 0130895717 3 0130284181

2 0135289106 4 0130895601


Table relationships in books


Manipulating Databases with JDBC

Seven Basic Steps in Using JDBC1. Load the driver2. Define the Connection URL3. Establish the Connection4. Create a Statement object5. Execute a query6. Process the results7. Close the connection


JDBC Drivers

• JDBC consists of two parts: – JDBC API, a purely

Java-based API – JDBC Driver Manager,which

communicates with vendor-specific drivers that perform the real communicationwith the database.

• Point: translation to vendorformat is performed onthe client

– No changes neededto server

– Driver (translator) neededon client

Database

JDBC Driver Manager

Java Application

JDBC API

JDBC Driver API

Vendor Specific JDBC Driver

Vendor SpecificODBC Driver

JDBC-ODBCBridge

Database


Connecting to and Querying a Database

•DisplayAuthors– Retrieves the entire authors table– Displays the data in the standard output stream– Example illustrates

• Connect to the database• Query the database• Process the result

• http://www.apl.jhu.edu/~hall/java/Servlet-Tutorial/Servlet-Tutorial-Intro.html


Example: DisplayAuthors.java (1) 1 // Fig. 25.25: DisplayAuthors.java

2 // Displaying the contents of the authors table.

3 import java.sql.Connection;

4 import java.sql.Statement;

5 import java.sql.DriverManager;

6 import java.sql.ResultSet;

7 import java.sql.ResultSetMetaData;

8 import java.sql.SQLException;

9

10 public class DisplayAuthors

11 {

12 // JDBC driver name and database URL

13 static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";

14 static final String DATABASE_URL = "jdbc:mysql://localhost/books";

15

16 // launch the application

17 public static void main( String args[] )

18 {

19 Connection connection = null; // manages connection

20 Statement statement = null; // query statement

21

22 // connect to database books and query database

23 try

24 {

25 Class.forName( JDBC_DRIVER ); // load database driver class

26

27 // establish connection to database

28 connection =

29 DriverManager.getConnection( DATABASE_URL, "jhtp6", "jhtp6" );

30

Imports the JDBC classes and interfaces from package java.sql.*

Specifies the JDBC driver’s class name

Specifies the database URL

Loads the database driver.

Declare and initialize a Connection reference


Example: DisplayAuthors.java (2)

31 // create Statement for querying database

32 statement = connection.createStatement();

33

34 // query database

35 ResultSet resultSet = statement.executeQuery(

36 "SELECT authorID, firstName, lastName FROM authors" );

37

38 // process query results

39 ResultSetMetaData metaData = resultSet.getMetaData();

40 int numberOfColumns = metaData.getColumnCount();

41 System.out.println( "Authors Table of Books Database:" );

42

43 for ( int i = 1; i <= numberOfColumns; i++ )

44 System.out.printf( "%-8s\t", metaData.getColumnName( i ) );

45 System.out.println();

46

47 while ( resultSet.next() )

48 {

49 for ( int i = 1; i <= numberOfColumns; i++ )

50 System.out.printf( "%-8s\t", resultSet.getObject( i ) );

51 System.out.println();

52 } // end while

53 } // end try

54 catch ( SQLException sqlException )

55 {

56 sqlException.printStackTrace();

57 System.exit( 1 );

58 } // end catch

Obtain an object that implements interface Statement.

execute a query

Obtains the metadata.

Retrieve the number of columns

Obtain column name

Position to the first row in the ResultSet with method next

Extract the contents of one column in the current row

Catch SQLException


Example: DisplayAuthors.java (3)

59 catch ( ClassNotFoundException classNotFound ) 60 { 61 classNotFound.printStackTrace(); 62 System.exit( 1 ); 63 } // end catch 64 finally // ensure statement and connection are closed properly 65 { 66 try 67 { 68 statement.close(); 69 connection.close(); 70 } // end try 71 catch ( Exception exception ) 72 { 73 exception.printStackTrace(); 74 System.exit( 1 ); 75 } // end catch 76 } // end finally 77 } // end main 78 } // end class DisplayAuthors Authors Table of Books Database: authorID firstName lastName 1 Harvey Deitel 2 Paul Deitel 3 Tem Nieto 4 Sean Santry

Close the Statement and the database Connection.

ClassNotFoundException is thrown if the class loader cannot locate the driver class


Popular JDBC driver names and database URL.

RDBMS JDBC driver name Database URL format

MySQL com.mysql.jdbc.Driver jdbc:mysql://hostname/databaseName

ORACLE oracle.jdbc.driver.OracleDriver

jdbc:oracle:thin:@hostname:port Number:databaseName

DB2 COM.ibm.db2.jdbc.net.DB2Driver

jdbc:db2:hostname:portnumber/data baseName

Sybase com.sybase.jdbc.SybDriver jdbc:sybase:Tds:hostname:portnuber/databaseName

For more information on JDBC drivers, visit the Sun Microsystems JDBC Web site, http://developers.sun.com/product/jdbc/drivers

CSC 411/511: DBMS Design

Dr. Nan Wang CSC411_L12_JDBC_MySQL21

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CSC 411/511: DBMS Design Dr. Nan WangCSC411_L12_JDBC_MySQL 1 MySQL and JDBC