In our last Selenium tutorial, we learned to troubleshoot some recurrent problems in Selenium scripts. We discussed some advanced concepts wherein we would deal with mouse and keyboard events, and accessing multiple links by implementing lists.

Moving ahead with our advanced topics in the Selenium training series, we will introduce you to the concept of Database testing using Selenium WebDriver.

We would discuss the basic processes like database connection, executing queries, fetching data disconnecting database instances, etc. We would also discuss various practical implications where we need database testing with automation testing to test the complete end-to-end scenarios.

Before moving ahead with the technical implications associated with Automated Database testing, let us discuss a few scenarios where we require performing Database testing along with Automation Testing.

Before moving forward, I want to clarify that Database testing is a specialized type of testing. Selenium WebDriver is a tool designed for simulating and automating user interactions with the Application UI. 

In essence, we’re not exactly conducting Database Testing, but testing our application and Database together to detect defects early. Absolutely all the web applications need a backend to store the Data. Databases like MySQL, Oracle, and SQL Server are reasonably popular these days.

Application of Database Testing and Automation Testing

Consider the following scenarios:

#1) At times, we need to ensure that the data entered from the UI consistently reflects in the database. Thus, we retrieve the information from the Database and verify the retrieved information against the information supplied from the UI.

For example, registration forms, user data, user profiles, updates, and deletes of user data. Thus, the test scenario to automate can be “To verify that the user’s information is successfully saved into the database as soon as the user registers in the application”.

#2) Another use case of performing database testing with Selenium WebDriver may arise when the user is directed to load the test data or expected data from the Database.

Thus, in such a case, the user would connect with the Database using a third-party API, execute queries to retrieve data from the dataset, and then assert the data fetched from the Database with the actual data that is populated on the Application UI.

#3) Another use case is to perform associative Database Testing. Assume that we performed an operation on the application’s UI, and we want to test the reflection in the Database. It may be a case that the impacted data resides in various tables of the database due to the association. Therefore, it is always advisable to test data reflection in all the impacted areas.

Selenium simulates the user interactions with the application under test. It can simulate keyboard events, mouse actions, etc. But if the user desires to automate anything outside the vicinity of browser-web application interactions, then selenium can’t be of much help. Thus, we require other tools or capabilities to perform end–to–end testing.

Thus, in all the above scenarios, we may be required to perform Database Testing along with UI Automation. We may check business logic by manipulating the data and verifying its reflection. We may also check the technical aspects of the Database itself, like soft delete, field validation, etc.

Let us now move ahead with the actual implementation. Before developing Selenium WebDriver scripts to extract data from the data source, let us create test data in the database. For this tutorial, we will use MySQL as a database.

Creation of Test Data in the Database

If you haven’t downloaded the database yet, download it using the link. The user is expected to follow some basic steps to download and install the database.

=>> Read this tutorial to download and install MySQL Database.

Once the database is installed, the user can open the MySQL Command Line Prompt, which will look like this screenshot. The application might ask the user to enter the password. The default password is “root”.

Note: Users can also find GUI-based clients over the internet to connect with the database. To name a few, the user can download and install the Query Browser or Work Bench.

Creation of a New Database

The next step is to create the test database with a few tables and records stored in those tables to connect with the database and execute queries.

Step #1: Type “show databases” to see all the already available databases

Step #2: Type “create database user;” to create a database named “user”.

Note, you’ll be able to see the database name in the list once the user is created.

Step #3: Type “use user;” to select the newly created database. Also, type “show tables;” to view all the tables available in the user database.

Take note that the Empty set is shown in the result of the “show tables;” query, as there were no tables available within the user database.

Let us now take a few tables and add records to them.

Step #4: Type the following command to create a table with 4 fields/columns (userId, userName, userAge, userAddress).

create table userinfo
(
userId int,
userName varchar(255),
userAge int,
userAddress varchar(255)
);

The next step is to add some data records to the “userinfo” table.

Step #5: Type the following command to insert data into the table a table for all four fields 4 fields/columns (userId, userName, userAge, userAddress).

insert into userinfo (userID, userName, userAge, userAddress) values ('1', 'shruti', '25', 'Noida');

To view the added data, type the following command:

Similarly, you can add more data to your table and can create other tables as well. Now, that we have created our database. We can move ahead and understand the implementation of automated queries to fetch the records from the database.

As we also iterated earlier, Selenium WebDriver is a tool for UI Automation. Thus, Selenium WebDriver alone is ineligible to perform database testing, but this can be done using Java Database Connectivity API (JDBC).

The API lets the user connect and interact with the data source and fetches the data with the help of automated queries. To exploit the JDBC API, it is required to have a Java Virtual Machine (JVM) running on the system.

JDBC Workflow

We would keep our focus aligned with the following processes:

1. Creating a connection with the database.
2. Executing queries and update statements to extract/fetch data (CRUD Operations).
3. Using and manipulating the data extracted from the Database as the result set. (Result set is a collection of data organized in rows and columns).
4. Disconnecting the database connection.

As said earlier, to test the database automatically from our Selenium WebDriver test scripts, we would connect with the Database via JDBC connectivity within our test scripts. Post to the connection, we can trigger as many CRUD (Create, Read, Update, and Delete) operations on the Database.

In this tutorial, we will discuss “Read operation and its variants” and their implementation in the Selenium WebDriver script. But before that, let us check the test scenario manually using the “MySQL command line”.

Scenario:

#1) Open the Database server and connect to the “user” database.

#2) List down all the records from the “userinfo” table.

Syntax: select * from userinfo;

#3) Close the Database connection.

Notice that the read query will list down all the user data present in the userinfo table. The table consists of the following columns.

• userId
• username
• userAge
• userAddress

The result also show that there is only a single data set present within the table.

Now, let us execute the same scenario using the Java Class.

To access the Database, the user is leveraged to choose amongst the diverse connector options available to connect with the Database. Most of the database connectors are freely distributed as “jar” files. As we are using MySQL as a data source, therefore we are required to download the jar file specific to MySQL.

The jar file can be downloaded from: here or here.

Step #1: The first and foremost step is to configure the project’s build path and add “mysql-connector-java-3.1.13-bin.jar” file as an external library.

Step #2: Create a java class named “DatabaseTesingDemo”.

Step #3: Copy and paste the below code into the class created in the above step.

Code Sample:

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
 
public class DatabaseTesingDemo {
       // Connection object
       static Connection con = null;
       // Statement object
       private static Statement stmt;
       // Constant for Database URL
       public static String DB_URL = "jdbc:mysql://localhost:3306/user";   
       // Constant for Database Username
       public static String DB_USER = "root";
       // Constant for Database Password
       public static String DB_PASSWORD = "root";
 
       @Before
       public void setUp() throws Exception {
              try{
                     // Make the database connection
                     String dbClass = "com.mysql.jdbc.Driver";
                     Class.forName(dbClass).newInstance();
                     // Get connection to DB
                     Connection con = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
                     // Statement object to send the SQL statement to the Database
                     stmt = con.createStatement();
                     }
                     catch (Exception e)
                     {
                           e.printStackTrace();
                     }
       }
 
       @Test
       public void test() {
              try{
              String query = "select * from userinfo";
              // Get the contents of userinfo table from DB
              ResultSet res = stmt.executeQuery(query);
              // Print the result untill all the records are printed
              // res.next() returns true if there is any next record else returns false
              while (res.next())
              {
                     System.out.print(res.getString(1));
              System.out.print("\t" + res.getString(2));
              System.out.print("\t" + res.getString(3));
              System.out.println("\t" + res.getString(4));
              }
              }
              catch(Exception e)
              {
                     e.printStackTrace();
              }     
       }
 
       @After
       public void tearDown() throws Exception {
              // Close DB connection
              if (con != null) {
              con.close();
              }
       }
}

The output of the above code is:

1      shruti 25     Noida
2      shrivastava   55     Mumbai

Read Statement Variants

Where clause with single condition

String query = "select * from userinfo where userId='" + 1 + "'";
ResultSet res = stmt.executeQuery(query);

Output:
1      shruti 25     Noida

Where clause with multiple conditions

String Address ="Mumbai";
String query = "select * from userinfo where userId='" + 2 + "' and userAddress='"+Address+"'";
ResultSet res = stmt.executeQuery(query);

Output:
2      shrivastava   55     Mumbai

Display userId

String query = "select userId from userinfo";
ResultSet res = stmt.executeQuery(query);

Output:
1
2

Display userId with where clause

String Address ="Noida";
String query = "select userId,userName from userinfo where userAddress='"+Address+"'";
ResultSet res = stmt.executeQuery(query);

Output:
2
shrivastava

Thus, in the same way, the user can execute various queries on the database.

With this, let us shed some light on result accessibility methods.

Result Accessibility Methods:

Result Navigation Methods:

Conclusion

Through this tutorial, we tried to make you acquainted with the concept of Automated Database Testing. We emphasized the technical implications and needs of Database Testing.

As our entire series was focused on Selenium, the reader may get misled and can create an impression that this tutorial would teach to perform Database testing using Selenium, but like I mentioned several times earlier, anything that lies outside the periphery of UI testing, cannot be handled by Selenium.

Therefore, we introduce Java Database Connectivity (JDBC) API to perform Database Testing by embedding the code within the Selenium WebDriver scripts.

JDBC makes it possible for the java class to connect to the Database, retrieve data from the database, or for a matter of fact, perform any of the CRUD operations, manipulate the resultant data, and close the connection.

Thus, the tutorial constitutes the basic sample implementation of the above-mentioned process.

Next Tutorial #29: We will move ahead with advanced Selenium topics. In the next tutorial, we will cover the Selenium GRID – which is used when you have to perform multi-browser testing and you have numerous test cases.