pjvds / electrodb

A DynamoDB library to ease the use of modeling complex hierarchical relationships and implementing a Single Table Design while keeping your query code readable.

ElectroDB

ElectroDB is a DynamoDB library to ease the use of having multiple entities and complex hierarchical relationships in a single DynamoDB table.

Please submit issues/feedback or reach out on Twitter @tinkertamper.

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New: Documentation now found at ElectroDB.dev

ElectroDB's new website for Documentation is now live at www.ElectroDB.dev.

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Introducing: The NEW ElectroDB Playground

Try out and share ElectroDB Models, Services, and Single Table Design at electrodb.fun

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Features

• Single-Table Entity Isolation - Entities created with ElectroDB will not conflict with other entities when using a single DynamoDB table.
• Attribute Schema Enforcement - Define a schema for your entities with enforced attribute validation, defaults, types, aliases, and more.
• Easily Compose Hierarchical Access Patterns - Plan and design hierarchical keys for your indexes to multiply your possible access patterns.
• Simplified Sort Key Condition Querying - Write efficient sort key queries by easily building compose keys.
• Simplified Filter Composition - Easily create complex readable filters for DynamoDB queries without worrying about the implementation of ExpressionAttributeNames, ExpressionAttributeValues, and FilterExpressions.
• Simplified Condition Composition - Use the same interface to casily create complex readable mutation conditions for DynamoDB queries without worrying about the implementation of ExpressionAttributeNames, ExpressionAttributeValues, and ConditionExpressions.
• Simplified Update Expression Composition - Easily compose type safe update operations without having to format tedious ExpressionAttributeNames, ExpressionAttributeValues, and UpdateExpressions.
• Easily Query Across Entities - Define "collections" to create powerful/idiomatic queries that return multiple entities in a single request.
• Automatic Index Selection - Use .find() or .match() methods to dynamically and efficiently query based on defined sort key structures.
• Simplified Pagination API - ElectroDB generates url safe cursors for pagination, allows for fine grain automated pagination, and supports async iteration.
• TypeScript Support - Strong TypeScript support for both Entities and Services now in Beta.
• Query Directly via the Terminal - Execute queries against your Entities, Services, Models directly from the command line.
• Stand Up Rest Server for Entities - Stand up a REST Server to interact with your Entities, Services, Models for easier prototyping.
• Use with your existing tables - ElectroDB simplifies building DocumentClient parameters, so you can use it with existing tables/data.

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Turn this

tasks
  .patch({ 
    team: "core",
    task: "45-662", 
    project: "backend"
  })
  .set({ status: "open" })
  .add({ points: 5 })
  .append({ 
    comments: [{
      user: "janet",
      body: "This seems half-baked."
    }] 
  })
  .where(( {status}, {eq} ) => eq(status, "in-progress"))
  .go();

Into This

{
    "UpdateExpression": "SET #status = :status_u0, #points = #points + :points_u0, #comments = list_append(#comments, :comments_u0), #updatedAt = :updatedAt_u0, #gsi1sk = :gsi1sk_u0",
    "ExpressionAttributeNames": {
        "#status": "status",
        "#points": "points",
        "#comments": "comments",
        "#updatedAt": "updatedAt",
        "#gsi1sk": "gsi1sk"
    },
    "ExpressionAttributeValues": {
        ":status0": "in-progress",
        ":status_u0": "open",
        ":points_u0": 5,
        ":comments_u0": [
            {
                "user": "janet",
                "body": "This seems half-baked."
            }
        ],
        ":updatedAt_u0": 1630977029015,
        ":gsi1sk_u0": "$assignments#tasks_1#status_open"
    },
    "TableName": "your_table_name",
    "Key": {
        "pk": "$taskapp#team_core",
        "sk": "$tasks_1#project_backend#task_45-662"
    },
    "ConditionExpression": "attribute_exists(pk) AND attribute_exists(sk) AND #status = :status0"
}