--- title: Introduction to CQRS using MongoDB | daily.dev description: A step-by-step tutorial implementing the CQRS (Command Query Responsibility Segregation) pattern using MongoDB, Java 21, Helidon MicroProfile, and Eclipse... canonical: https://daily.dev/posts/introduction-to-cqrs-using-mongodb-qdpqeqjeh twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Introduction to CQRS using MongoDB | daily.dev og:description: A step-by-step tutorial implementing the CQRS (Command Query Responsibility Segregation) pattern using MongoDB, Java 21, Helidon MicroProfile, and Eclipse... og:url: https://daily.dev/posts/introduction-to-cqrs-using-mongodb-qdpqeqjeh og:image: https://api.daily.dev/og/posts/QDpqEqjEH.png og:image:alt: Introduction to CQRS using MongoDB og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Introduction to CQRS using MongoDB **[Foojay.io](https://daily.dev/sources/foojayio)** · 10 min read · 1 upvotes · 0 comments ## Summary A step-by-step tutorial implementing the CQRS (Command Query Responsibility Segregation) pattern using MongoDB, Java 21, Helidon MicroProfile, and Eclipse JNoSQL. The example models a card authorization system, separating write operations (commands) from read operations (queries) into distinct entities and REST resources. The command side handles card authorization and records OperationResult documents, while the query side serves a denormalized TransactionView optimized for reads. The tutorial walks through entity creation, command handler implementation, and query resource setup with full code samples. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [CQRS in Java: Separating Reads and Writes Cleanly](https://daily.dev/posts/cqrs-in-java-separating-reads-and-writes-cleanly-2mdeyndjt) · Foojay.io · 0 upvotes · 0 comments - [Optimizing Search Performance with CQRS: Relational Writes and NoSQL Reads](https://daily.dev/posts/optimizing-search-performance-with-cqrs-relational-writes-and-nosql-reads-3zldezxon) · Sergio Lema · 9 upvotes · 0 comments --- Tags: [#java](https://daily.dev/tags/java), [#mongodb](https://daily.dev/tags/mongodb) [View this post on daily.dev](https://daily.dev/posts/introduction-to-cqrs-using-mongodb-qdpqeqjeh) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Introduction to CQRS using MongoDB","url":"https://daily.dev/posts/introduction-to-cqrs-using-mongodb-qdpqeqjeh","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/introduction-to-cqrs-using-mongodb-qdpqeqjeh"},"datePublished":"2026-06-09T10:02:25.679Z","dateModified":"2026-06-09T10:02:51.704Z","description":"A step-by-step tutorial implementing the CQRS (Command Query Responsibility Segregation) pattern using MongoDB, Java 21, Helidon MicroProfile, and Eclipse...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/b2bc2e20de7b965f644c9bb9b4fb7a8a?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/b2bc2e20de7b965f644c9bb9b4fb7a8a?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Foojay.io","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Foojay.io","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/1820f6a6ae944760aa322b67ed85f848","url":"https://daily.dev/sources/foojayio"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/introduction-to-cqrs-using-mongodb-qdpqeqjeh","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"java,mongodb","timeRequired":"PT10M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Foojay.io","item":"https://daily.dev/sources/foojayio"},{"@type":"ListItem","position":3,"name":"Introduction to CQRS using MongoDB"}]} ```