Database Testing

Database Testing Tutorial: Complete Guide, Checklist, Test Cases & Interview Questions (2026)

Database Testing is one of the most important parts of Software Testing. It verifies that data stored in a database is accurate, secure, consistent, and reliable.

Modern applications like Banking, E-Commerce, Healthcare, and Social Media depend on databases. A small database error can create major business problems.

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What is Database Testing?

Database Testing is the process of testing database objects, data, and operations to ensure that the application stores and retrieves correct information.

Database testing verifies:

• Data correctness
• Data integrity
• Database security
• Database performance
• Relationships between tables
• Stored procedures and triggers

Real Time Example of Database Testing

Suppose a user creates an account in an online shopping application.

User Registration:

Name: Rahul Sharma
Email: rahul@gmail.com
Password: 123456

Database should store:

UserId | Name          | Email
--------------------------------
1      | Rahul Sharma  | rahul@gmail.com

Tester verifies:

• User record created successfully
• Email stored correctly
• Duplicate email rejected
• Password is encrypted
• User can login successfully

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Why Database Testing is Important?

• Prevents data loss
• Improves application quality
• Finds database errors early
• Improves application performance
• Ensures data security

Types of Database Testing

1. Structural Database Testing

This testing checks database structure.

• Tables
• Columns
• Data Types
• Primary Keys
• Foreign Keys
• Constraints

Employee Table

EmployeeId INT PRIMARY KEY
Name VARCHAR(50)
Salary INT

2. Functional Database Testing

This verifies database functionality.

Example Login Query:

SELECT *
FROM Users
WHERE Email='test@gmail.com'
AND Password='12345'

Expected Result:

• Valid user should login
• Invalid user should be rejected

3. Data Integrity Testing

It verifies relationships between tables.

Customer Table

CustomerId
CustomerName


Order Table

OrderId
CustomerId
Amount

An order should not exist without a customer.

4. Database Performance Testing

Checks:

• Query execution time
• Database response time
• Index performance

5. Database Security Testing

Checks:

• User permissions
• Authentication
• Authorization
• SQL Injection

Input:

' OR 1=1 --

Expected:
Login should fail

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Database Testing Process

Step 1: Understand Database Design

• Database Schema
• ER Diagram
• Table Relationship
• Stored Procedures

Step 2: Prepare Test Data

CREATE TABLE Employee
(
EmployeeId INT PRIMARY KEY,
Name VARCHAR(50),
Salary INT
)

Insert Data:

INSERT INTO Employee
VALUES(1,'Amit',60000)

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Complete Database Testing Checklist

Table Testing Checklist

• ✓ Verify table exists
• ✓ Verify table name
• ✓ Verify columns
• ✓ Verify datatype
• ✓ Verify column size
• ✓ Verify default values
• ✓ Verify NULL values
• ✓ Verify constraints

Primary Key Testing

• Primary key exists
• Duplicate values not allowed
• NULL values not allowed

INSERT INTO Employee
VALUES(1,'John',50000)


Again:

INSERT INTO Employee
VALUES(1,'Alex',70000)

Expected: Duplicate Key Error

Foreign Key Testing

• Relationship exists
• Parent record required
• Delete rules working

NULL Value Testing

INSERT INTO Employee(Name)
VALUES(NULL)

Expected: Insert should fail

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Database CRUD Test Cases

Test Case 1: Insert Record

INSERT INTO Employee
VALUES(1,'Rahul',50000)

Expected: Record inserted successfully.

Test Case 2: Update Record

UPDATE Employee
SET Salary=70000
WHERE EmployeeId=1

Expected: Salary updated.

Test Case 3: Delete Record

DELETE FROM Employee
WHERE EmployeeId=1

Expected: Record deleted.

Test Case 4: Duplicate Record Testing

SELECT Email,COUNT(*)
FROM Users
GROUP BY Email
HAVING COUNT(*)>1

Expected: No duplicate records.

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Transaction Testing

Example: Bank Money Transfer

BEGIN TRANSACTION

UPDATE Account
SET Balance=Balance-1000
WHERE Id=1


UPDATE Account
SET Balance=Balance+1000
WHERE Id=2


COMMIT

Verify:

• Amount deducted once
• Amount added once
• Transaction completed

Rollback Testing

BEGIN TRANSACTION

UPDATE Account
SET Balance=Balance-5000

ROLLBACK

Expected: Previous data restored.

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Important SQL Queries for Testers

Find Duplicate Data

SELECT Email,COUNT(*)
FROM Users
GROUP BY Email
HAVING COUNT(*)>1

Find NULL Records

SELECT *
FROM Users
WHERE Email IS NULL

Count Records

SELECT COUNT(*)
FROM Users

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Database Testing Tools

• SQL Server Management Studio
• MySQL Workbench
• Oracle SQL Developer
• JMeter
• LoadRunner
• DBUnit

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Database Testing Interview Questions

1. What is Database Testing?

Database testing verifies data accuracy, integrity, security, and performance.

2. What is Primary Key?

A primary key uniquely identifies each record in a table.

3. What is Foreign Key?

A foreign key creates a relationship between two tables.

4. Explain ACID Properties

• Atomicity
• Consistency
• Isolation
• Durability

5. DELETE vs TRUNCATE

DELETE: Removes selected rows and supports rollback.

TRUNCATE: Removes all records and is faster.

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Final Database Testing Checklist

DATABASE TESTING CHECKLIST

✓ Table Verification
✓ Column Verification
✓ Data Type Validation
✓ Primary Key Testing
✓ Foreign Key Testing
✓ Constraint Testing
✓ NULL Testing
✓ Default Value Testing
✓ CRUD Testing
✓ Stored Procedure Testing
✓ Trigger Testing
✓ View Testing
✓ Index Testing
✓ Transaction Testing
✓ Rollback Testing
✓ Security Testing
✓ SQL Injection Testing
✓ Performance Testing
✓ Backup Testing
✓ Recovery Testing

Conclusion

Database Testing is a critical skill for every Software Tester. A strong understanding of SQL, database concepts, queries, and testing techniques helps testers identify defects and deliver reliable applications.

Labels: Database Testing, SQL Testing, Software Testing, QA Testing, Manual Testing