cassaflow

A Clojure library for working with Apache Cassandra, providing idiomatic Clojure interfaces with named parameter support and automatic result conversion.

Features

• 🔌 Simple connection management
• 📝 Named parameter support (:param style)
• 🗺️ Automatic conversion of results to Clojure maps
• 🎯 Flexible query execution with options
• 🧪 Full integration test suite with Testcontainers
• ⚡ Built on DataStax Java Driver 4.x

Installation

Add the following dependency to your project.clj:

[io.github.caioclavico/cassaflow "0.1.0"]

Or in deps.edn:

{:deps {io.github.caioclavico/cassaflow {:mvn/version "0.1.0"}}}

Quick Start

(require '[cassaflow.client :as client])
(require '[cassaflow.core :as cass])

;; Connect to Cassandra
(def session (client/connect {:host "127.0.0.1" :port 9042}))

;; Execute queries with automatic map conversion
(cass/execute session "SELECT * FROM users")
;; => ({:id "1" :name "Alice" :age 30} {:id "2" :name "Bob" :age 25})

;; Use named parameters
(cass/execute session 
              "SELECT * FROM users WHERE id = :id" 
              {:id "1"})
;; => ({:id "1" :name "Alice" :age 30})

;; Get a single result
(cass/execute session 
              "SELECT * FROM users WHERE id = :id" 
              {:id "1"}
              {:one? true})
;; => {:id "1" :name "Alice" :age 30}

;; Clean up
(.close session)

Usage

Connecting to Cassandra

(require '[cassaflow.client :as client])

;; Connect with default settings (localhost:9042)
(def session (client/connect))

;; Connect to a specific host and port
(def session (client/connect {:host "cassandra.example.com" 
                              :port 9042}))

;; Don't forget to close the session when done
(.close session)

Executing Queries

(require '[cassaflow.core :as cass])

;; Simple SELECT - returns sequence of maps
(cass/execute session "SELECT * FROM users")
;; => ({:id "1" :name "Alice" :age 30} {:id "2" :name "Bob" :age 25})

;; SELECT with named parameters
(cass/execute session 
              "SELECT * FROM users WHERE id = :id" 
              {:id "1"})
;; => ({:id "1" :name "Alice" :age 30})

;; Get single result with :one? option
(cass/execute session 
              "SELECT * FROM users WHERE id = :id" 
              {:id "1"}
              {:one? true})
;; => {:id "1" :name "Alice" :age 30}

;; INSERT with named parameters
(cass/execute session
              "INSERT INTO users (id, name, age) VALUES (:id, :name, :age)"
              {:id "3" :name "Charlie" :age 35})

;; UPDATE with named parameters
(cass/execute session
              "UPDATE users SET age = :age WHERE id = :id"
              {:id "1" :age 31})

;; DELETE with named parameters
(cass/execute session
              "DELETE FROM users WHERE id = :id"
              {:id "3"})

;; Get raw ResultSet if needed
(cass/execute session 
              "SELECT * FROM users"
              nil
              {:raw? true})
;; => #<ResultSet ...>

Working with Results

Results are automatically converted to Clojure maps with keyword keys:

(let [users (cass/execute session "SELECT * FROM users")]
  (doseq [user users]
    (println (:name user) "is" (:age user) "years old")))

Query Options

The execute function accepts an optional map of options:

• :raw? - Returns the raw ResultSet instead of converted maps (default: false)
• :one? - Returns a single map instead of a sequence (default: false)

Development

Running Tests

# Run all tests
lein test

# Run only unit tests
lein test cassaflow.core-test cassaflow.query-test

# Run only integration tests (requires Docker)
lein test :integration

Integration Tests

Integration tests use Testcontainers to spin up a real Cassandra instance in Docker. Make sure Docker is running before executing integration tests.

License

Copyright © 2024

This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.

This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.

Contributing

Contributions are welcome! Please visit the GitHub repository.