In the previous JDBC tutorial named as types of jdbc drivers in java we learned about what is JDBC in java and JDBC drivers in java .

In this JDBC tutorial we will learn how to create jdbc connection in java or java database connectivity  with mysql or jdbc connection in java with oracle.

JDBC Connection Steps

All these  java database connectivity or jdbc drivers in java steps are explained here with their code .

Class.forName (“sun.jdbc.odbc.JdbcOdbcDriver”); //for JDBC-ODBC Bridge

Parameter passed in forName() method to connect with different database are as follows:

To connect with MySql – Class.forName (“org.gjt.mm.mysql.Driver”);

Step 3 – Create a Connection

Once the Driver has been loaded after that we need to established the connection using Connection Class object. The syntax is given below –

Connection conn = DriverManager.getConnection(“jdbcURL”,”username”,”password”);

Three types of statement can be used  Statement, PreparedStatement and CallableStatement. Here we are explaining syntax for each type.

Java Syntax for all three types of Statement are given below –

The while will execute until the rows are found in the table record will retrieved from table  and result will be displayed

This is important to note that prepared statement java PreparedStatement is better as compare to Statement.

Some differences between prepared statement java PreparedStatement and Statement are explained here

In case of  PreparedStatement it means prepared statement java query remains in the parsed form.

Generally SQL statements can belong to any one of the two categories: static or dynamic.

With a static query the string does not change you create it once then call it over and over again.

In contrast  with a dynamic query you create a new SQL command by concatenating strings and variables after that instantiating a new Statement object and executing that command.

Either way each time we execute a new command the database must compile the SQL code.

This compilation can include various activities such as costly syntax checking, name validation, and pseudo code generation.

From the database performance point of view we should use prepared statement java PreparedStatement.

A PreparedStatement is provide the Java encapsulation of a parameterized query in which the SQL statement compiles a single time but it can execute many times.

If we want to change the query conditions then we employ placeholders (?) within the statement to indicate bind variables.

After such bind variables (parameters to the query) are set the query executes.

JDBC Connection Steps Example

In the following program we are connecting our application program to Database named CS1 through JDBC connection Steps.

All the jdbc conncetion steps explained above are implemented in this program

import java.sql.*;

class MysqlCon
{

public static void main(String args[])
{

try
{
Class.forName(“com.mysql.jdbc.Driver”);

Connection con = DriverManager.getConnection(“jdbc:mysql://localhost:3306/cs1″,”root”,”roo”);

//here cs1 is database name, root is username and password

Statement stmt=con.createStatement();

ResultSet rs = stmt.executeQuery(“select * from student”);

while(rs.next())
{
System.out.println( rs.getInt(1)+” “+ rs.getString(2) +” “+ rs.getString(3));
}

con.close();
}
catch(Exception e)
{
System.out.println(e);
}
}
}