Testing mode

All qa.cafe features are currently free. Features and test data can change before launch.

qa.cafe
Sign in
BeginnerData

SQL for QA Engineers

Learn database foundations and practical SQL through disposable SQLite labs designed for QA work. SQLite keeps every exercise safely in your browser. lessons clearly identify concepts or syntax that differ in PostgreSQL, SQL Server, MySQL, Oracle, and other database engines.

SQLiteSQLData validationJoinsTest dataDatabase investigation
Learning outcomes

What you’ll be able to do.

01

Explain tables, keys, relationships, constraints, schemas, and indexes

02

Write useful filters, joins, aggregations, and data-quality queries

03

Prepare and change test data safely with transactions

04

Compare UI and API behavior with persisted database evidence

Curriculum

8 focused modules.

32 lessons total
01Why SQL matters and what this course will teach youUnderstand why SQL matters in QA work. Preview the knowledge, practical skills, and outcomes that you will build.
  1. ↳What a database is and why QA caresLesson
  2. ↳Tables, rows, columns, and data typesLesson
  3. ↳Keys, relationships, and constraintsLesson
  4. ↳Database engines, schemas, and SQL dialectsLesson
02Reading evidence with SELECTAsk precise read-only questions before changing data.
  1. ↳Understanding the QA sample databaseLesson
  2. ↳Selecting columns and creating aliasesLesson
  3. ↳Removing duplicates with DISTINCTLesson
  4. ↳Sorting and limiting resultsLesson
03Filtering real application statesTurn test questions into deliberate predicates.
  1. ↳WHERE and comparison operatorsLesson
  2. ↳AND, OR, NOT, and precedenceLesson
  3. ↳IN, BETWEEN, and LIKELesson
  4. ↳NULL and three-valued logicLesson
04Shaping and inspecting dataTransform raw values into useful QA evidence.
  1. ↳Text functionsLesson
  2. ↳Numeric and date functions in SQLiteLesson
  3. ↳Conditional output with CASELesson
  4. ↳Missing, malformed, and duplicated dataLesson
05Connecting related recordsValidate workflows that span tables.
  1. ↳Reasoning about foreign keysLesson
  2. ↳INNER JOINLesson
  3. ↳LEFT JOIN and missing relationshipsLesson
  4. ↳Multi-table joins and accidental duplicatesLesson
06Aggregating evidenceSummarize behavior without losing meaning.
  1. ↳COUNT, SUM, AVG, MIN, and MAXLesson
  2. ↳GROUP BYLesson
  3. ↳Filtering groups with HAVINGLesson
  4. ↳Building QA metrics and duplicate checksLesson
07Preparing test data safelyPractice writes in a disposable lab and build safe habits.
  1. ↳Creating fixtures with INSERTLesson
  2. ↳Safe UPDATE statementsLesson
  3. ↳DELETE, constraints, and referential integrityLesson
  4. ↳Transactions, rollback, and environment safetyLesson
08QA investigations and capstoneConnect SQL evidence to product decisions.
  1. ↳Validating UI and API results against stored dataLesson
  2. ↳Tracing a defect across related recordsLesson
  3. ↳SQLite, other engines, indexes, and investigation habitsLesson
  4. ↳Capstone: investigate a broken order workflowLesson
Continue exploring

Related courses

All courses →
Manual testing Beginner

API Testing for Manual QA

Learn how modern applications communicate and test REST, SOAP, GraphQL, gRPC, and WebSockets with practical tools.

HTTP and REST curl and Postman Swagger and OpenAPI
48 lessons36 hours
Foundations Beginner

IT Fundamentals for Digital Teams

Learn how software, networks, web applications, APIs, databases, cloud systems, delivery, testing, and security fit together—without needing a technical background.

Technical literacy Systems thinking Web and API fundamentals
64 lessons48 hours
Test automation Beginner

JavaScript for QA Automation

Learn JavaScript from the beginning and use it to create clear data checks, assertions, and asynchronous QA workflows.

JavaScript values and control flow Functions and scope Arrays, objects, and JSON
48 lessons36 hours