This document discusses connectivity in SQL and JDBC. It begins by explaining that JDBC is a Java API that allows Java programs to execute SQL statements. It then describes the JDBC architecture and drivers. The responsibilities of the JDBC client include establishing a connection, submitting SQL statements, processing results, and closing the connection. The document outlines the steps to develop a Java/JDBC application, including loading and registering drivers, establishing a connection, preparing and executing statements, processing result sets, and closing connections. Finally, it compares Statement and PreparedStatement objects.

1. Connectivity in SQL & JDBC
Presented by:
Harshita Joshi

2. JDBC
• JDBC is J2SE technology.
• It is data accessing technology from sun
microsystem
• JDBC is a specification which is provided by
sun microsystem for driver manufacturers
• JDBC is API

3. JDBC Architecture

4. JDBC client
• Any resources sake request making program is
known as JDBC client
Application JDBC Driver

5. Responsibilities of JDBC client
• Establishing connection with database
• Submitting appropriate SQL statement to the
DBMS to perform CRUD operation
• Processing and presenting the result
• Deal with Exception
• After performing crude operation closing
connection

6. JDBC API
• JDBC API is collection of library methods,
using which our java program perform CRUD
operation on database
• To make API available for our program we
have to import java.sql package

7. DriverManager
• DriverManager is a library class or java.sql
package which is used for establishing
connection
• After receiving connection request from JDBC
client
• After establishing connection DriverManager
rolls end

8. JDBC Driver
• JDBC driver is a translation software which is
written in java.
• According to JDBC specification i.e Driver
manufacturers implements JDBC API.

9. JDBC Drivers
• JDBC-ODBC Bridge drivers (follows ODBC
standards)
• Partly Java – Partly Native (this does not use
any standards)
• Pure Java – Net Protocol Drivers
• Pure Java Drivers (also called Type4Drivers,
most popular one)

10. Type 1 Driver (jdbc - odbc bridge
driver )
Java App
that uses
JDBC API
Jdbc
driver
type1
ODBC Driver
for Oracle
ODBC Driver
for MS-Access
Vendor
DB
Library
for Oracle
Oracle
DB
Vendor
DB
Library
for M S
Access
MS
Access

11. Type 4 Driver
(Native Protocol All Java Driver)
Java App
that uses
JDBC API
Jdbc
driver
type4
Oracle
DB
Jdbc
driver
type4
MS
Access

12. Steps to develop java/jdbc App
• Load the JDBC Driver class and register with
DriverManager
• Establish the connection with database s/w
• Prepare Statement object
• Execute the query
• Get result and process the result
• Close the connection

13. Loading & Registering a Driver
• The driver class libraries need to be in the
CLASSPATH for the Java compiler and for
the Java virtual machine
• Class.forName(string).newInstance();
• Eg:
Class.forName("com.microsoft.jdbc.sqlserv
er.SQLServerDriver");

14. Establishing a Connection
• A connection string includes the literal jdbc:,
followed by the name of the driver and a URL to
the database
• Connection conn =
DriverManager.getConnection(string);
• Connection connection =
DriverManager.getConnection(
"jdbc:microsoft:sqlserver://127.0.0.1ABCD:1443;”
+ “DatabaseName=JDBCDB","username",
"password");

15. Ex- String url = "jdbc:odbc:datasource";
try {
Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con =
DriverManager.getConnection(url);
}
catch (ClassNotFoundException e)
{ e.printStackTrace(); }
catch (SQLException e)
{ e.printStackTrace(); }

16. Statement
• Acts as a courier service to send queries to the
db software.
• A Statement object is used for executing a
static SQL statement and obtaining the results
produced by it.

17. a. Create statement
Statement stmt = conn.createStatement();
stmt object sends SQL commands to database
– Methods
• executeQuery() for SELECT statements
• executeUpdate() for INSERT, UPDATE, DELETE,
statements
b. Send SQL statements
– stmt.executeQuery(“SELECT …”);
– stmt.executeUpdate(“INSERT …”);

18. ResultSet
• A ResultSet object is a java object which can store
bunch of selected rows given by select query
execution.
• Only one ResultSet per Statement can be open at
once.
• The table rows are retrieved in sequence.
• A ResultSet maintains a cursor pointing to its
current row of data.
• The 'next' method moves the cursor to the next row.

19. • boolean next()
– activates the next row
– the first call to next() activates the first row
– returns false if there are no more rows
• void close()
– disposes of the ResultSet
– allows you to re-use the Statement that created it
• Type getType(int columnIndex)
– returns the given field as the given type
– fields indexed starting at 1 (not 0)
• Type getType(String columnName)
– same, but uses name of field
– less efficient

20. ResultSet Methods
• String getString(int columnIndex)
• boolean getBoolean(int columnIndex)
• byte getByte(int columnIndex)
• short getShort(int columnIndex)
• int getInt(int columnIndex)
• long getLong(int columnIndex)
• float getFloat(int columnIndex)
• double getDouble(int columnIndex)
• Date getDate(int columnIndex)
• Time getTime(int columnIndex)
• Timestamp getTimestamp(int columnIndex)

21. Process results
• Result of a SELECT statement (rows/columns)
returned as a ResultSet object
– ResultSet rs =
stmt.executeQuery("SELECT * FROM users");
• Step through each row in the result
– rs.next()
• Get column values in a row
– String userid = rs.getString(“userid”);
– int type = rs.getInt(“type”);

22. ResultSet rs = stmt.executeQuery("SELECT *
FROM users");
while (rs.next()) {
String userid = rs.getString(1);
String firstname = rs.getString(“firstname”);
String lastname = rs.getString(“lastname”);
String password = rs.getString(4);
int type = rs.getInt(“type”);
System.out.println(userid + ” ” + firstname + ” ”
+ lastname + ” ” + password + ” ” + type);
}
users table
userid firstname lastname password type
Bob Bob King cat 0
John John Smith pass 1

23. Program
import java.sql.*;
public class Tester {
public static void main(String[] args) {
try {
// Load JDBC driver
Class.forName("com.mysql.jdbc.Driver").newInstance();
// Make connection
String url =
“jdbc:mysql://128.100.53.33/GRP?user=USER&password=PASS”
Connection conn = DriverManager.getConnection(url);

24. // Create statement
Statement stmt = conn.createStatement();
// Print the users table
ResultSet rs = stmt.executeQuery("SELECT *
FROM users");
while (rs.next()) {
...
}
// Cleanup
rs.close(); stmt.close(); conn.close();
} catch (Exception e) {
System.out.println("exception " + e);
}
}

25. Limitations of Statement Object
• DB s/w parses the same query multiple no. of
times and executes, fetches the o/p .
• Framing query for simple Statement object
using variable is quite unnecessary.
• Network traffic to the DB s/w is heavy since
same query goes multiple no. of times to the
DB s/w.
• To overcome these problems use precompiled
queries.

26. PreparedStatement Object
• A query that goes and resides on the DB s/w without
values by becoming parsed query is a precompiled
query.
• Precompiled queries will be parsed only once, but
capable of executing multiple times with same or
different values.
• PreparedStatement object represents this
precompiled query.
• When to use Statement object and
PreparedStatement object ?

27. Steps to work with
PreparedStatement
• Prepare the query having positional parameters.
String query=“insert into item values(?,?,?,?)”;
• Positional parameter indicates value to that query
will be set afterwards.
• Create PreparedStatement object.

28. • PreparedStatement ps=con.prepareStatement(query);
• Set the values for positional paremeters using
setType(-,-) methods.
–ps.setInt(-,-), ps.setString(-,-)
• Execute the query
–int result = ps.executeUpdate();
• For more executions repeat step 3 & 4.
• Close PreparedStatement object
–ps.close()

29. • PreparedStatement ps = con.prepareStatement ("insert
into emp values(?,?,?)");
• ps.setInt(1,23);
• ps.setString(2,"Roshan");
• ps.setString(3, "CEO");
• ps.executeUpdate();
• ps.close()

30. JDBC Object Classes
• DriverManager
– Loads, chooses drivers
• Driver
– connects to actual database
• Connection
– a series of SQL statements to and from the DB
• Statement
– a single SQL statement
• ResultSet
– the records returned from a Statement

31. JDBC Class Usage
DriverManager
Driver
Connection
Statement
ResultSet

32. Thank you!