Importance of SQL for testers

A Test Engineer may or may not require SQL specialization it depends on the project requirement

If the projects of database where the data has to be tested then the sql knowledge is must . If the testers is hired for only front end testing then there is no requirement of SQL knowledge and if the testers is hired for the backend testing then sql knowledge is must.

If a tester is having and additional knowledge of SQL queries this will make him stand out of the crowd.and knowledge of database and sql will also help them in

• Recognition of different types of databases.

• Connecting databases using sql connection.

• Understanding the relationship between database tables,keys and indices

• Writing simple to complex join sql queries

• Interpreting complex queries.

SQL statements that are frequently used in testing are:

• DML (Data Manipulation Language):Used to store,modify,retriever,delete,insert and update values in database. Examples: SELECT, UPDATE and INSERT statements.

• DDL(Data Definition Language): Used to modify and create the structure of objects in databases. Examples: CREATE, ALTER and DROP statements.

• TCL(Transactional Control Language): Manages different transactions occurring within the database.

• Inner Join: Retrieves the common records from tables

• Distinct: This operator is used to get the different values from one or more fields.

• In: This operator is widely used to determine the value lies in the given range or not

• Between: This retrieves the values that lies within the defined range.

• Order By Clause:This operator is used to manage the data in ascending or descending order as required

• Group By: Use Group By statements with the aggregate function to group the result set with one or more columns.

Some projects where the sql skills is less required

• Testing the application from the user perspective or black box testing

• Mobile testing when the focus is totally on the UI,user-friendly,usability and accessibility.

• Cross browser compatibility testing

Some projects where SQL skills are mandatory

• Database upgrades

• Data warehouse or business intelligence projects

• Data migrations or conversions

SQL skills are like other skills that one can gain easily with lots of practice- once done it will benefit in many ways.

• It will help you to find additional work

• It may be helpful in a project where you need to check the values

Learning basic SQL skills and having good understanding of how relational databases work is a valuable knowledge to acquire. I would like to suggest testers to acquire basic knowledge of sql to become ‘all around’ versatile tester that clients need and value.