This document provides an introduction and overview of Java Database Connectivity (JDBC). It discusses what JDBC is, the different types of JDBC drivers, how to connect to databases using JDBC, and how to execute SQL statements and process result sets. It also covers how to access database metadata and provides examples of using JDBC to connect to and query a Microsoft Access database.

1. 242-301 Adv. CoE Lab: JDBC 1
• Objective
– to give some background on JDBC to
help with the lab exercises
Introduction to Java
Database Connectivity
(JDBC)

2. 242-301 Adv. CoE Lab: JDBC 2
Overview
1. What is JDBC?
2. The JDBC-ODBC Bridge
3. Four Types of JDBC Drivers
4. JDBC Pseudocode
5. SimpleJDBC.java
Continued

3. 242-301 Adv. CoE Lab: JDBC 3
6. Meta Data
7. Using MS Access
8. Books.accdb as an ODBC
Data Source
9. Data Source Problems
10. More Information

4. 242-301 Adv. CoE Lab: JDBC 4
1. What is JDBC?
• JDBC is an interface which allows Java
code to execute SQL statements inside relati
onal databases
– the databases must follow the ANSI SQL-2
standard

5. 242-301 Adv. CoE Lab: JDBC 5
JDBC in Use
Java
program
connectivity
data processing
utilities
JDBC
driver
for Oracle
driver
for Sybase
jdbc-odbc
bridge
odbc
driver
Green means
"Java code"

6. 242-301 Adv. CoE Lab: JDBC 6
2. The JDBC-ODBC Bridge
• ODBC (Open Database Connectivity) is a
Microsoft standard from the mid 1990’s.
• It is an API that allows C/C++ programs to
execute SQL inside databases
• ODBC is supported by many products.
Continued

7. 242-301 Adv. CoE Lab: JDBC 7
• The JDBC-ODBC bridge allows Java code
to use the C/C++ interface of ODBC
– it means that JDBC can access many different
database products
• The layers of translation (Java --> C -->
SQL) can slow down execution.
Continued

8. 242-301 Adv. CoE Lab: JDBC 8
• The JDBC-ODBC bridge comes free with
the JDK:
– called sun.jdbc.odbc.JdbcOdbcDriver
• The ODBC driver for Microsoft Access
comes with MS Office
– so it is easy to connect Java and Access

9. 242-301 Adv. CoE Lab: JDBC 9
3. Four Types of JDBC Driver
• 1. JDBC-ODBC Bridge (type 1)
– translate Java to the ODBC API
– used by many Windows-based databases, e.g.
MS-Access
• 2. Database Protocol Driver (type 4)
– Independent from the OS/hardware because the
driver is in Java.
Continued

10. 242-301 Adv. CoE Lab: JDBC 10
• 3. Native API Connection Driver (type 2)
– connected by a OS native module, dependent
on the OS or hardware
(e.g. DLLs on Windows)
• 4. Net Connection Driver (type 3)
– use Java to access the database via networking
middleware (usually TCP/IP)
– required for networked applications

11. 242-301 Adv. CoE Lab: JDBC 11
JDBC Drivers
• A very long list of drivers (freeware,
shareware, and commercial) can be found at
:
http://www.oracle.com/technetwork/java/
index-136695.html

12. 242-301 Adv. CoE Lab: JDBC 12
4. JDBC as a Diagram
DriveManager Connection Statement ResultSet
creates creates creates
Driver
SQL
SQL
data
data
make link
to driver
Green means
"Java code"

13. 242-301 Adv. CoE Lab: JDBC 13
DriveManager
• It is responsible for establishing the
connection to the database through the driver
.
• e.g.
Class.forName(
"sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn =
DriveManager.getConnection(url);
name of the database

14. 242-301 Adv. CoE Lab: JDBC 14
Name the Database
• The name and location of the database is
given as a URL
– the details of the URL vary depending on the
type of database that is being used

15. 242-301 Adv. CoE Lab: JDBC 15
ODBC Database URL
jdbc:odbc: //host.domain.com: 2048 /data/file
The comms
protocol
The machine
holding the
database.
The port
used for the
connection.
The path to
the database
on the machine
e.g. jdbc:odbc:Books

16. 242-301 Adv. CoE Lab: JDBC 16
Statement Object
• The Statement object provides a
‘workspace’ where SQL queries can be crea
ted, executed, and results collected.
• e.g.
Statement st =
conn.createStatement():
ResultSet rs = st.executeQuery(
“ select * from Authors” );
:
st.close();

17. 242-301 Adv. CoE Lab: JDBC 17
ResultSet Object
• Stores the results of a SQL query.
• A ResultSet object is similar to a
‘table’ of answers, which can be examine
d by moving a ‘pointer’ (cursor).
Continued

18. 242-301 Adv. CoE Lab: JDBC 18
• Cursor operations:
– first(), last(), next(), previous(), etc.
• Typical code:
while( rs.next() ) {
// process the row;
}
23
5
17
98
John
Mark
Paul
Peter
cursor

19. 242-301 Adv. CoE Lab: JDBC 19
5. SimpleJDBC.java
// SimpleJDBC.java
// Displays the firstnames and lastnames
// of the Authors table in the Books db.
import java.sql.*;
public class SimpleJDBC {
public static void main(String[] args)
{
// The URL for the Books database.
// ’Protected' by a login and password.
String url = "jdbc:odbc:Books";
String username = "anonymous";
String password = "guest";
:

20. 242-301 Adv. CoE Lab: JDBC 20
try {
// load the JDBC-ODBC Bridge driver
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
// connect to db using DriverManager
Connection conn =
DriverManager.getConnection( url,
username, password );
// Create a statement object
Statement statement = conn.createStatement();
// Execute the SQL query
ResultSet rs = statement.executeQuery(
"SELECT lastName, firstName FROM
Authors" );
:

21. 242-301 Adv. CoE Lab: JDBC 21
// Print the result set
while( rs.next() )
System.out.println(
rs.getString("lastName") + ", " +
rs.getString("firstName") );
// Close down
statement.close();
conn.close();
}
:

22. 242-301 Adv. CoE Lab: JDBC 22
catch ( ClassNotFoundException cnfex ) {
System.err.println(
"Failed to load JDBC/ODBC driver." );
cnfex.printStackTrace();
System.exit( 1 ); // terminate program
}
catch ( SQLException sqlex ) {
System.err.println( sqlex );
sqlex.printStackTrace();
}
} // end of main()
} // end of SimpleJDBC class

23. 242-301 Adv. CoE Lab: JDBC 23
Section 8
not done.
Section 8
now done.
Output

24. 242-301 Adv. CoE Lab: JDBC 24
• If you've done section 8, but still gettingIf you've done section 8, but still getting
error messages, then check out section 9.error messages, then check out section 9.
• If you're still having problems, please comeIf you're still having problems, please come
to see Aj. Andrew.to see Aj. Andrew.

25. 242-301 Adv. CoE Lab: JDBC 25
5.1. Username & Password
• The database’s link to the outside (e.g. its
ODBC interface) must be configured to hav
e a login and password
– details for ODBC are given later

26. 242-301 Adv. CoE Lab: JDBC 26
5.2. Accessing a ResultSet
• The ResultSet class contains many
methods for accessing the value of a
column of the current row
– can use the column name or position
– e.g. get the value in the lastName column:
rs.getString("lastName")
Continued

27. 242-301 Adv. CoE Lab: JDBC 27
• The ‘tricky’ aspect is that the values are
SQL data, and so must be converted to Java
types/objects.
• There are many methods for accessing/
converting the data, e.g.
– getString(), getDate(), getInt(),
getFloat(), getObject()

28. 242-301 Adv. CoE Lab: JDBC 28
6. Meta Data
• Meta data is the information about the
database:
– e.g. the number of columns, the types of the
columns
– meta data is the schema information
ID Name Course Mark
007 James Bond Shooting 99
008 Aj. Andrew Kung Fu 1
meta data

29. 242-301 Adv. CoE Lab: JDBC 29
• One important use for metadata is forOne important use for metadata is for
formatting result set dataformatting result set data
– e.g. instead of displaying the results as text,e.g. instead of displaying the results as text,
display them in a Java table with headers, rows,display them in a Java table with headers, rows,
columnscolumns
• see TableDisplay.java in the Exercisessee TableDisplay.java in the Exercises

30. 242-301 Adv. CoE Lab: JDBC 30
6.1. Accessing Meta Data
• The getMetaData() method can be used
on a ResultSet object to create its meta da
ta object.
• e.g.
ResultSetMetaData md =
rs.getMetaData();

31. 242-301 Adv. CoE Lab: JDBC 31
6.2. Using Meta Data
int numCols = md.getColumnCount();
for (int i = 0; i <= numCols; i++) {
if (md.getColumnType(i) ==
Types.CHAR)
System.out.println(
md.getColumnName(i) )
}

32. 242-301 Adv. CoE Lab: JDBC 32
6.3. More Meta Data Methods
• getTableName()
• getPrecision()
– number of decimal digits in the column
• isSigned()
– returns true if column has signed numbers
• isCurrency()
• etc.

33. 242-301 Adv. CoE Lab: JDBC 33
7. Using MS Access7. Using MS Access
• MS Access changed its file formats whenMS Access changed its file formats when
Access 2007 was released:Access 2007 was released:
– for Access 2003 (and earlier) you should usefor Access 2003 (and earlier) you should use
Books.Books.mdbmdb
– for Access 2007 or 2010, you should usefor Access 2007 or 2010, you should use
Books.Books.accdbaccdb
– both versions are in the lab's website.both versions are in the lab's website.

34. 242-301 Adv. CoE Lab: JDBC 34
Access and SQLAccess and SQL
• How to use SQL in Access is described at:How to use SQL in Access is described at:
– http://www.jaffainc.com/SQLStatementsInAccess.htmhttp://www.jaffainc.com/SQLStatementsInAccess.htm
And on the
website, in
sqlAccess2007
.txt and
sql_intr.pdf
And on the
website, in
sqlAccess2007
.txt and
sql_intr.pdf

35. 242-301 Adv. CoE Lab: JDBC 35
TableRelationships in Books.accdb
(and Books.mdb)
Under Database Tools > Relationships

36. 242-301 Adv. CoE Lab: JDBC 36
8. Books.accdb as an ODBC Data Source
• 1. Click on
“Data Sources
(ODBC)” in
“Administrative
Tools” folder in
the Control
Panel.

37. 242-301 Adv. CoE Lab: JDBC 37
• Select the MS Access Data Source.Select the MS Access Data Source.
Press “Add’ to add a data source.
If you don't find
MS Access here,
then go to
Section 9.

38. 242-301 Adv. CoE Lab: JDBC 38
• Select the English
Microsoft Access
Driver (*.mdb,
*.accdb).
Press “Finish”.

39. 242-301 Adv. CoE Lab: JDBC 39
• 3. Type in the
"Books"
source name,
any description,
and press “Select”
to browse to set
the path to the
Books.accdb or
Books.mdb file.
Click on
“Advanced”.

40. 242-301 Adv. CoE Lab: JDBC 40
• 4. Type in a username
and password (guest).
Click “Ok” repeatedly
until all the dialog
boxes are gone.

41. 242-301 Adv. CoE Lab: JDBC 41
9. Data Source Problems9. Data Source Problems
• Two problems may occur when using JDBCTwo problems may occur when using JDBC
with the data source set up in Section 8:with the data source set up in Section 8:
– "No suitable driver found for jdbc: odbc:"No suitable driver found for jdbc: odbc:
driver={Microsoft Access Driver (*.mdb)};...driver={Microsoft Access Driver (*.mdb)};...
– "The specified DSN contains an architecture mismatch"The specified DSN contains an architecture mismatch
between the Driver and Application"between the Driver and Application"
• These problems are usually due to youThese problems are usually due to you
using the 64-bit version of Windows 7.using the 64-bit version of Windows 7.

42. 242-301 Adv. CoE Lab: JDBC 42
• Check your version of Windows byCheck your version of Windows by
following the steps listed at:following the steps listed at:
– http://support.microsoft.com/kb/827218http://support.microsoft.com/kb/827218
means
32-bit

43. 242-301 Adv. CoE Lab: JDBC 43
Which Version of Access?Which Version of Access?
• Check whether you are using the 32-bit orCheck whether you are using the 32-bit or
64-bit version of Access:64-bit version of Access:
– look at the "Help" dialoglook at the "Help" dialog

44. 242-301 Adv. CoE Lab: JDBC 44
Win7 64-bit & Access 64-bitWin7 64-bit & Access 64-bit
• You may need to download the 64-bitYou may need to download the 64-bit
Access drivers from:Access drivers from:
– http://www.microsoft.com/http://www.microsoft.com/
en-us/download/details.aspx?id=13255en-us/download/details.aspx?id=13255
– executeexecute AccessDatabaseEngine_x64.exe
• You should also be using theYou should also be using the 64-bit64-bit versionversion
of Java for Windows. get it from:of Java for Windows. get it from:
– http://www.java.com/en/download/http://www.java.com/en/download/

45. 242-301 Adv. CoE Lab: JDBC 45
Win 7 64-bit & AccessWin 7 64-bit & Access 32-bit32-bit
• Set up the data source using the 32-bitSet up the data source using the 32-bit
ODBC control panel at:ODBC control panel at:
– c:windowssysWOW64odbcad32.exec:windowssysWOW64odbcad32.exe
• You should also be using theYou should also be using the 32-bit32-bit versionversion
of Java for Windows. Get it from:of Java for Windows. Get it from:
– http://www.java.com/en/download/http://www.java.com/en/download/

46. 242-301 Adv. CoE Lab: JDBC 46
10. More Information
• Ivor Horton’s Beginning Java 2, JDK 5
Edition, Wiley Publishing, 2005
Chapters 24 and 25 (starts on p.1306)
• Advanced Java 2 Platform: How to Program
Deitel & Deitel, Prentice-Hall, 2001
Chapter 8
http://java.coe.psu.ac.th/ForMember/
Continued

47. 242-301 Adv. CoE Lab: JDBC 47
• JDBC Wikipaedia page:
• http://en.wikipedia.org/wiki/JDBC_driver
• The Java Documentation and tutorial
– http://docs.oracle.com/javase/tutorial/
– the JDBC Database Access ‘trail’ is very good
– http://docs.oracle.com/javase/tutorial/
jdbc/index.html