DynamoDB CRUD Lite

JavaScript library for simplified CRUD operations on DynamoDB tables.

Table of Contents

• Installation
• Usage
• Contributing
• License

Installation

To install the DynamoDB CRUD Lite, you can use npm:

npm install @shimoku/dynamodb-crud-lite

Usage

To use the DynamoDB CRUD Lite, import the functions you need from the library:

import { createItem, updateItem, deleteItem, query, scan } from '@shimoku/dynamodb-crud-lite';

Creating an Item

The createItem function allows you to create an item in a DynamoDB table. It takes in the table name and an object containing the attributes of the item to be created as its parameters. Attributes id, createdAt, and updatedAt are automatically added to the item with the following values: id is set to a new UUID v4, createdAt and updatedAt are set to the current timestamp in format yyyy-MM-ddTHH:mm:ss.sssZ.

const item = await createItem('tableName', { attribute1: 'value1', attribute2: 'value2' });

Updating an Item

The updateItem function allows you to update an item in a DynamoDB table. It takes in the table name, the hash key value of the item to be updated (assuming that a id attribute is the hash key of the table), and an object containing the attributes to be updated as its parameters. The updatedAt attribute is automatically updated with the current timestamp in format yyyy-MM-ddTHH:mm:ss.sssZ.

const item = await updateItem('tableName', 'id', { attribute1: 'value1', attribute2: 'value2' });

Deleting an Item

The deleteItem function allows you to delete an item from a DynamoDB table. It takes in the table name and the id of the item to be deleted as its parameters.

const item = await deleteItem('tableName', 'id');

Querying Items

The query function allows you to retrieve items from a DynamoDB table by either their id or by using an indexName. The function takes in the table name and a query object as its parameters.

The query object can contain the following properties to specify the search criteria:

• id: Retrieves the item with the specific id.
• indexName: The name of the index to be used in querying the table (if the table has global secondary indexes).
• hashKeyName and hashKeyValue: The name and value of the hash key to be used in querying the table.
• rangeKeyName and rangeKeyValue: The name and value of the range key to be used in querying the table.
• filterExpression: A filter expression used to filter the items returned from the query.
• filterNames: An object that maps the names of attributes in the filter expression to their corresponding attribute names in the DynamoDB table.
• filterValues: An object that maps the names of the attribute values in the filter expression to their corresponding values.
• limit: A limit on the number of items returned by the query.
• exclusiveStartKey: The exclusive start key to be used in querying the table.

The function returns a promise that resolves to the following object:

• If the query is performed by id, the item with the matching id is returned.
• If the query is performed by indexName, an object containing an array of items (items) and a LastEvaluatedKey property. The LastEvaluatedKey property is a base64 encoded string that can be used as the exclusiveStartKey in the next query.

Note: If the query is performed by id and no item is found, the promise is rejected with an error message "Item not found".

const item = await query('tableName', { id: 'id' });

const items = await query('tableName', { indexName: 'indexName', hashKeyName: 'hashKeyName', hashKeyValue: 'hashKeyValue' });

Scanning Items

The scan function allows you to retrieve data from a DynamoDB table by scanning the entire table. It takes in the table name and an optional query object as its parameters.

• filterExpression: A string that represents the filter to be applied to the scan operation.
• filterNames: An object that maps the attribute names in filterExpression to their respective attribute names in the table.
• filterValues: An object that maps the placeholders in filterExpression to their respective values.
• limit: The maximum number of items to be retrieved by the scan operation.
• exclusiveStartKey: A base64 encoded string that represents the primary key of the item after which the scan operation is to begin.

The function returns a promise that resolves to an object containing the following properties:

• items: An array of items retrieved by the scan operation.
• LastEvaluatedKey: A base64 encoded string that represents the primary key of the last item evaluated in the scan operation. This can be used as the exclusiveStartKey in the next query.

Note: If there are no more items to retrieve in the table, LastEvaluatedKey will be undefined.

const items = await scan('tableName', { filterExpression: 'attribute1 = :value1', filterValues: { ':value1': 'value1' } });

Contributing

We welcome contributions to the DynamoDB CRUD Lite. To contribute, please fork the repository and create a pull request with your changes.

License

The DynamoDB CRUD Lite is released under the MIT License.