--- title: "SQL: Query Fundamentals & Database Concepts" lang: "en" author: "Mohammad Abu Mattar" canonical: https://mkabumattar.com/post/sql-query-fundamentals-quiz --- [Home](/)›[Quizzes](/quizzes)›[All Categories](/quizzes/categories)›[SQL](/quizzes/categories/sql) Quizzes [SQL](/quizzes/categories/sql)[Databases](/quizzes/categories/databases)[Quizzes](/quizzes/categories/quizzes) # SQL: Query Fundamentals & Database Concepts [Mohammad Abu Mattar](/authors/mohammad-abu-mattar)20 QuestionsBeginnerPublished: 21 Feb 2026 [Markdown for AI(opens in a new tab)](/post/sql-query-fundamentals-quiz/index.md "Open the plain-Markdown version of this page, for pasting into an AI tool") Series [Databases & Data Persistence](/series/databases--data-persistence)1/4 [NextMongoDB: NoSQL Database Fundamentals](/quizzes/post/mongodb-nosql-fundamentals-quiz) All posts in this series (4) Quizzes4 1. [SQL: Query Fundamentals & Database ConceptsYou are here](/quizzes/post/sql-query-fundamentals-quiz) 2. [MongoDB: NoSQL Database Fundamentals](/quizzes/post/mongodb-nosql-fundamentals-quiz) 3. [Elasticsearch: Full-Text Search Engine Fundamentals](/quizzes/post/elasticsearch-search-engine-fundamentals-quiz) 4. [Database Design & Patterns](/quizzes/post/database-design-patterns-quiz) ## SQL: Query Fundamentals & Database Concepts Up to 20 questions, shuffled on every run Quiz Configuration Enterto start Welcome to the SQL Basics Quiz! Relational databases hold the data behind most modern applications. Whether you’re a developer writing queries or a DevOps engineer maintaining a production cluster, mastering SQL is essential for data integrity and system performance. This quiz will test your knowledge from basic selection to complex joins and database management. Good luck! Answer key and explanations20 questions The quiz above draws 20 questions at random from these 30, so a second attempt will not be the same run. Everything in the pool is listed here. 1. What does "SQL" stand for? AnswerStructured Query Language 2. Which SQL statement is used to extract data from a database? AnswerSELECT 3. Which clause is used to filter records based on a specific condition? AnswerWHERE 4. What is the purpose of the "INNER JOIN" keyword? AnswerTo return records that have matching values in both tables 5. Which SQL command is used to update existing data in a table? AnswerUPDATE 6. What is a "Primary Key"? AnswerA column that uniquely identifies each row in a table 7. What is a "Foreign Key"? AnswerA column that establishes a relationship between two tables 8. How do you sort the result set in SQL? AnswerORDER BY 9. What is the "LEFT JOIN" keyword used for? AnswerTo return all records from the left table and matched records from the right 10. What is "Database Normalization"? AnswerOrganizing data to minimize redundancy and maximize data integrity 11. Which SQL command is used to remove a table from a database? AnswerDROP 12. What is the "GROUP BY" clause used for? AnswerTo arrange rows with identical values into summary rows 13. Which aggregate function finds the number of rows in a table? AnswerCOUNT() 14. What is the "HAVING" clause used for? AnswerTo filter groups based on a condition after aggregation 15. What does "NULL" represent in SQL? AnswerThe state of a value being missing or unknown 16. Which keyword is used to return only unique values? AnswerDISTINCT 17. What is the purpose of the "LIKE" operator? AnswerTo search for a specified pattern within a string column 18. What is a "Transaction" in SQL? AnswerA unit of work that succeeds or fails as a complete set 19. What is an "Index" used for? AnswerTo provide a faster lookup path for retrieving data rows 20. Which SQL command is used to add new rows to a table? AnswerINSERT INTO 21. What is a "View" in SQL? AnswerA virtual table based on the results of a stored query 22. What does the "AS" keyword do? AnswerIt creates a temporary alias for a column or table in a query 23. What is a "Constraint" in SQL? AnswerA rule enforced on columns to ensure data accuracy and reliability 24. Which command changes the structure of an existing table? AnswerALTER TABLE 25. What is "Referential Integrity"? AnswerThe consistency between tables maintained via foreign key constraints 26. What does the "UNION" operator do? AnswerIt combines the results of two SELECT statements into one set 27. What is a "Stored Procedure"? AnswerA group of SQL statements that can be saved and reused 28. What is the "TRUNCATE" command? AnswerIt removes all records from a table while keeping the structure 29. What does "ACID" stand for in database terms? AnswerAtomicity, Consistency, Isolation, Durability 30. What is the difference between "DELETE" and "TRUNCATE"? AnswerDELETE can remove specific rows, whereas TRUNCATE empties the whole table ## Tags [#Sql](/quizzes/tags/sql)[#Sql fundamentals](/quizzes/tags/sql-fundamentals)[#Relational databases](/quizzes/tags/relational-databases)[#Queries](/quizzes/tags/queries)[#Joins](/quizzes/tags/joins)[#Database design](/quizzes/tags/database-design)[#Normalization](/quizzes/tags/normalization)[#Indexes](/quizzes/tags/indexes)[#Transactions](/quizzes/tags/transactions)[#Acid properties](/quizzes/tags/acid-properties)[#Data integrity](/quizzes/tags/data-integrity)[#Sql quiz](/quizzes/tags/sql-quiz)[#Database concepts](/quizzes/tags/database-concepts) ## Share [Facebook](https://facebook.com/sharer/sharer.php?u=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz "Share on Facebook")[Twitter](https://twitter.com/intent/tweet/?text=SQL%3A%20Query%20Fundamentals%20%26%20Database%20Concepts&url=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz "Share on Twitter")[LinkedIn](https://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz&title=SQL%3A%20Query%20Fundamentals%20%26%20Database%20Concepts&summary=Master%20the%20fundamentals%20of%20Relational%20Databases%2C%20from%20basic%20SELECT%20statements%20to%20complex%20JOIN%20operations%20and%20database%20normalization.&source=https://mkabumattar.com "Share on LinkedIn")[WhatsApp](https://wa.me/?text=SQL%3A%20Query%20Fundamentals%20%26%20Database%20Concepts%20https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz "Share on WhatsApp")[Telegram](https://t.me/share/url?url=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz&text=SQL%3A%20Query%20Fundamentals%20%26%20Database%20Concepts "Share on Telegram")[Reddit](https://www.reddit.com/submit?url=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz&title=SQL%3A%20Query%20Fundamentals%20%26%20Database%20Concepts "Share on Reddit")[Hacker News](http://news.ycombinator.com/submitlink?u=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz&t=SQL%3A%20Query%20Fundamentals%20%26%20Database%20Concepts "Share on Hacker News")[Pinterest](https://pinterest.com/pin/create/button/?url=https%3A%2F%2Fmkabumattar.com%2Fquizzes%2Fpost%2Fsql-query-fundamentals-quiz&media=&description=Master%20the%20fundamentals%20of%20Relational%20Databases%2C%20from%20basic%20SELECT%20statements%20to%20complex%20JOIN%20operations%20and%20database%20normalization. "Share on Pinterest")[Email]() ## Comments Was this useful? ## You might also enjoy More posts on similar topics [![MongoDB: NoSQL Database Fundamentals](/_astro/hero.CicgKvnW_2qJCIK.webp)](/quizzes/post/mongodb-nosql-fundamentals-quiz) ## [MongoDB: NoSQL Database Fundamentals](/quizzes/post/mongodb-nosql-fundamentals-quiz) - [Mohammad Abu Mattar](/authors/mohammad-abu-mattar) - [NoSQL](/quizzes/categories/nosql) - [MongoDB](/quizzes/categories/mongodb) - [Quizzes](/quizzes/categories/quizzes) Welcome to the MongoDB Basics Quiz! NoSQL databases changed the way we handle modern web scale data. Understanding the document model, the flexibility of BSON, and the aggregation pipeline matters for [#Mongodb](/quizzes/tags/mongodb)[#Nosql](/quizzes/tags/nosql)[#Document database](/quizzes/tags/document-database)+10 tags [read more](/quizzes/post/mongodb-nosql-fundamentals-quiz) [![Elasticsearch: Full-Text Search Engine Fundamentals](/_astro/hero.1OsSVxzV_1XbYRD.webp)](/quizzes/post/elasticsearch-search-engine-fundamentals-quiz) ## [Elasticsearch: Full-Text Search Engine Fundamentals](/quizzes/post/elasticsearch-search-engine-fundamentals-quiz) - [Mohammad Abu Mattar](/authors/mohammad-abu-mattar) - [Elasticsearch](/quizzes/categories/elasticsearch) - [Search](/quizzes/categories/search) - [Quizzes](/quizzes/categories/quizzes) Welcome to the Elasticsearch Basics Quiz! Elasticsearch sits behind a large share of log analysis and real-time search. Whether you are troubleshooting a production crash by digging through Filebeat l [#Elasticsearch](/quizzes/tags/elasticsearch)[#Full text search](/quizzes/tags/full-text-search)[#Search engines](/quizzes/tags/search-engines)+11 tags [read more](/quizzes/post/elasticsearch-search-engine-fundamentals-quiz) [![Database Design & Patterns](/_astro/hero.C_gmtZ96_ZtTczJ.webp)](/quizzes/post/database-design-patterns-quiz) ## [Database Design & Patterns](/quizzes/post/database-design-patterns-quiz) - [Mohammad Abu Mattar](/authors/mohammad-abu-mattar) - [Backend](/quizzes/categories/backend) - [Database](/quizzes/categories/database) Welcome to the Database Design & Patterns Quiz! Test your knowledge on database normalization, indexing, query optimization, ACID properties, sharding, replication, and more. Each question has a hint [#Database](/quizzes/tags/database)[#Design](/quizzes/tags/design)[#Performance](/quizzes/tags/performance) [read more](/quizzes/post/database-design-patterns-quiz) [![GraphQL Fundamentals: Queries, Mutations & Schema Design](/_astro/hero.D7HMB0_s_1Ij4Vw.webp)](/quizzes/post/graphql-fundamentals-quiz) ## [GraphQL Fundamentals: Queries, Mutations & Schema Design](/quizzes/post/graphql-fundamentals-quiz) - [Mohammad Abu Mattar](/authors/mohammad-abu-mattar) - [GraphQL](/quizzes/categories/graphql) - [API Development](/quizzes/categories/api-development) - [Quizzes](/quizzes/categories/quizzes) Welcome to the GraphQL Basics Quiz! Learning GraphQL well matters for building efficient, flexible APIs that let clients request exactly what they need. This quiz will test your understanding of core [#Graphql](/quizzes/tags/graphql)[#Graphql fundamentals](/quizzes/tags/graphql-fundamentals)[#Api development](/quizzes/tags/api-development)+11 tags [read more](/quizzes/post/graphql-fundamentals-quiz) [![Redis: In-Memory Caching & Data Structures](/_astro/hero.DnN4-uPB_Z1uPLOl.webp)](/quizzes/post/redis-caching-fundamentals-quiz) ## [Redis: In-Memory Caching & Data Structures](/quizzes/post/redis-caching-fundamentals-quiz) - [Mohammad Abu Mattar](/authors/mohammad-abu-mattar) - [Databases](/quizzes/categories/databases) - [DevOps](/quizzes/categories/devops) - [Caching](/quizzes/categories/caching) Welcome to the Redis Basics Quiz! Redis serves data from memory, which is why it sits in front of so many databases. Whether it is used as a simple cache, a data structure store, or a real-time messag [#Redis](/quizzes/tags/redis)[#NoSQL](/quizzes/tags/nosql)[#In Memory](/quizzes/tags/in-memory)+1 tags [read more](/quizzes/post/redis-caching-fundamentals-quiz) [![Istio: Service Mesh Fundamentals](/_astro/hero.ic-MS8aq_Z8sHT8.webp)](/quizzes/post/istio-service-mesh-fundamentals-quiz) ## [Istio: Service Mesh Fundamentals](/quizzes/post/istio-service-mesh-fundamentals-quiz) - [Mohammad Abu Mattar](/authors/mohammad-abu-mattar) - [Istio](/quizzes/categories/istio) - [Service Mesh](/quizzes/categories/service-mesh) - [Quizzes](/quizzes/categories/quizzes) Welcome to the Istio Basics Quiz! Istio is often the "final boss" of Kubernetes infrastructure. It adds traffic control and security that production-grade microservices depend on. This quiz will test [#Istio](/quizzes/tags/istio)[#Service mesh](/quizzes/tags/service-mesh)[#Kubernetes](/quizzes/tags/kubernetes)+11 tags [read more](/quizzes/post/istio-service-mesh-fundamentals-quiz) 6 related posts