Web Driver cannot directly connect to Database. You can only interact with your Browser using Web Driver. For this we use JDBC("Java Database Connectivity").The JDBC API is a Java API for accessing virtually any kind of tabular data.The value of the JDBC API is that an application can access virtually any data source and run on any platform with a Java Virtual Machine.

In simplest terms, a JDBC technology-based driver ("JDBC driver") makes it possible to do three things:

1.Establish a connection with a data source
2.Send queries and update statements to the data source
3.Process the results

1.Establish a connection with a data source
The traditional way to establish a connection with a database is to call the method
DriverManager.getConnection(URL,  "username", "password" )
URL :   jdbc:<subprotocol>:<subname>
<subprotocol>-the name of the driver or the name of a database connectivity mechanism
<subname> - The point of a subname is to give enough information to locate the data source .(Includes IP address , Port number and exact name of DataSource)

For connecting to MYSQL URL will bejdbc:mysql://localhost:3306/hoale

2.Send queries and update statements to the data source
A Statement object is used to send SQL statements to a database over the created connection in Step 1.
Statement-created by the Connection.createStatement methods. A Statement object is used for sending SQL statements with no parameters.
PreparedStatement-created by the Connection.prepareStatement methods. A PreparedStatement object is used for precompiled SQL statements. These can take one or more parameters as input arguments (IN parameters).
CallableStatement-created by the Connection.prepareCall methods. CallableStatement objects are used to execute SQL stored procedures
In Short
createStatement methods-for a simple SQL statement (no parameters)
prepareStatement methods-for an SQL statement that is executed frequently
prepareCall methods-for a call to a stored procedure
3.Process the results
A ResultSet is a Java object that contains the results of executing an SQL query.We will have separate post on it.The JDBC API provides three interfaces for sending SQL statements to the database

Here is the code for it.
String url1 ="jdbc:mysql://localhost:3306/hoale";
           // Load Microsoft SQL Server JDBC driver
           String dbClass = "com.mysql.jdbc.Driver";
           Class.forName(dbClass).newInstance();
           //Get connection to DB
           Connection con = DriverManager.getConnection(url1,"root", "");
           //Create Statement
           Statement stmt = (Statement) con.createStatement();
           // method which returns the requested information as rows of data
           ResultSet result = (ResultSet) stmt.executeQuery("select * from employee");

The below example illustrates how to use/connect MySQL with Selenium using Java. 

Prerequisites:

-      mysql-connector-java-5.1.0-bin.jar  or above versions
-      Create table Employee in Navicat

This is example for connection DataBase(mysql) using Selenium WebDriver
package com;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;

import com.mysql.jdbc.ResultSet;
import com.mysql.jdbc.Statement;
import com.thoughtworks.selenium.SeleneseTestBase;

public class ConnectDB extends SeleneseTestBase{
     WebDriver driver;
     String url ="";
     @BeforeTest
public void setUp() throws Exception{
     driver = new FirefoxDriver();
     url ="file:///D:/ECLIPSE/workspace_eclipseclassic
             /ConnectDB/src/com/modules/HTML5Demo.html";
     driver.get(url);
}
     @Test
     public void CreateDB() throws InstantiationException,
 IllegalAccessException, ClassNotFoundException, SQLException{
           //Prepare connection
           String url1 ="jdbc:mysql://localhost:3306/hoale";
           // Load Microsoft SQL Server JDBC driver
           String dbClass = "com.mysql.jdbc.Driver";
           Class.forName(dbClass).newInstance();
           //Get connection to DB
           Connection con = DriverManager.getConnection(url1, "root", "");
           //Create Statement
           Statement stmt = (Statement) con.createStatement();
           // method which returns the requested information as rows of data
           ResultSet result = (ResultSet) stmt.executeQuery("select * from employee");
           if(result.next())
           {
                String id = result.getString("ID");
                String info = result.getString("Info");
                driver.getCurrentUrl();
                WebElement a = driver.findElement(By.id("txtID"));
                a.sendKeys(id);
                WebElement b = driver.findElement(By.id("txtInfo"));
                b.sendKeys(info);
                WebElemen btnclick= driver.findElement(By.id("btnclick"));
                btnclick.click();
                System.out.print("Passed");
           }
     }
    
     @AfterTest
public void tearDown(){
     driver.close();
}

}