Use Azure Table Storage

This How to is based on the Medium article by Andrew Varnon

The implementation is done using a Smart Collection and a CRUD service that will wrap the Azure Table Storage API.

The Table Storage Definition

You can use the new Azure Data Explorer to create and populate a Table Storage in your Azure Storage account.

In our example, we are going to use the Table Customers with the fields:

  • Id: PartitionKey + RowKey

  • Timestamp (updated at)

  • Email as String

  • FirstName as String

  • LastName as String

Install Azure data-tables package

npm install @azure/data-tables --save

Smart Collection definition

const { collection } = require('forest-express-sequelize');
collection('customers', {
fields: [{
field: 'id',
type: 'String',
get: (customer) => `${customer.partitionKey}|${customer.rowKey}`,
}, {
field: 'partitionKey',
type: 'String',
}, {
field: 'rowKey',
type: 'String',
}, {
field: 'timestamp',
type: 'Date',
}, {
field: 'Email',
type: 'String',
}, {
field: 'LastName',
type: 'String',
}, {
field: 'FirstName',
type: 'String',
}, ],
});

The Azure Data Tables Service Wrapper

const { TableClient } = require('@azure/data-tables');
const getClient = (tableName) => {
const client = TableClient.fromConnectionString(
process.env.AZURE_STORAGE_CONNECTION_STRING,
tableName);
return client;
}
const azureTableStorageService = {
deleteEntityAsync: async (tableName, partitionKey, rowKey) => {
const client = getClient(tableName);
await client.deleteEntity(partitionKey, rowKey);
},
getEntityAsync: async (tableName, partitionKey, rowKey) => {
const client = getClient(tableName);
return client.getEntity(partitionKey, rowKey);
},
listEntitiesAsync: async (tableName, options) => {
const client = getClient(tableName);
var azureResponse = await client.listEntities();
let iterator = await azureResponse.byPage({maxPageSize: options.pageSize});
for (let i = 1; i < options.pageNumber; i++) iterator.next(); // Skip pages
let entities = await iterator.next();
let records = entities.value.filter(entity => entity.etag);
// Load an extra page if we need to allow (Next Page)
const entitiesNextPage = await iterator.next();
let nbNextPage = 0;
if (entitiesNextPage && entitiesNextPage.value) {
nbNextPage = entitiesNextPage.value.filter(entity => entity.etag).length;
}
// Azure Data Tables does not provide a row count.
// We just inform the user there is a new page with at least x items
const minimumRowEstimated = (options.pageNumber-1) * options.pageSize + records.length + nbNextPage;
return {records, count: minimumRowEstimated};
},
createEntityAsync: async (tableName, entity) => {
const client = getClient(tableName);
delete entity['__meta__'];
await client.createEntity(entity);
return client.getEntity(entity.partitionKey, entity.rowKey);
},
udpateEntityAsync: async (tableName, entity) => {
const client = getClient(tableName);
await client.updateEntity(entity, "Replace");
return client.getEntity(entity.partitionKey, entity.rowKey);
},
};
module.exports = azureTableStorageService;

Routes definition

const express = require('express');
const { PermissionMiddlewareCreator, RecordCreator, RecordUpdater } = require('forest-express');
const { RecordSerializer } = require('forest-express');
const router = express.Router();
const COLLECTION_NAME = 'customers';
const permissionMiddlewareCreator = new PermissionMiddlewareCreator(COLLECTION_NAME);
const recordSerializer = new RecordSerializer({ name: COLLECTION_NAME });
const azureTableStorageService = require("../services/azure-table-storage-service");
// Get a list of Customers
router.get(`/${COLLECTION_NAME}`, permissionMiddlewareCreator.list(), async (request, response, next) => {
const pageSize = parseInt(request.query.page.size) || 15;
const pageNumber = parseInt(request.query.page.number);
azureTableStorageService.listEntitiesAsync(COLLECTION_NAME, {pageSize, pageNumber})
.then( async ({records, count}) => {
const recordsSerialized = await recordSerializer.serialize(records);
response.send({ ...recordsSerialized, meta: { count }});
})
.catch ( (e) => {
console.error(e);
next(e);
});
});
// Get a Customer
router.get(`/${COLLECTION_NAME}/:recordId`, permissionMiddlewareCreator.details(), async (request, response, next) => {
const parts = request.params.recordId.split('|');
azureTableStorageService.getEntityAsync(COLLECTION_NAME, parts[0], parts[1])
.then( (record) => recordSerializer.serialize(record))
.then( (recordSerialized) => response.send(recordSerialized))
.catch ( (e) => {
console.error(e);
next(e);
});
});
// Create a Customer
router.post(`/${COLLECTION_NAME}`, permissionMiddlewareCreator.create(), async (request, response, next) => {
const recordCreator = new RecordCreator({name: COLLECTION_NAME});
recordCreator.deserialize(request.body)
.then( (recordToCreate) => {
return azureTableStorageService.createEntityAsync(COLLECTION_NAME, recordToCreate);
})
.then((record) => recordSerializer.serialize(record))
.then((recordSerialized) => response.send(recordSerialized))
.catch ( (e) => {
console.error(e);
next(e);
});
});
// Update a Customer
router.put(`/${COLLECTION_NAME}/:recordId`, permissionMiddlewareCreator.update(), async (request, response, next) => {
const parts = request.params.recordId.split('|');
const recordUpdater = new RecordUpdater({name: COLLECTION_NAME});
recordUpdater.deserialize(request.body)
.then( (recordToUpdate) => {
recordToUpdate.partitionKey = parts[0];
recordToUpdate.rowKey = parts[1];
return azureTableStorageService.udpateEntityAsync(COLLECTION_NAME, recordToUpdate);
})
.then( (record) => recordSerializer.serialize(record) )
.then( (recordSerialized) => response.send(recordSerialized) )
.catch ( (e) => {
console.error(e);
next(e);
});
});
// Delete a list of Customers
router.delete(`/${COLLECTION_NAME}`, permissionMiddlewareCreator.delete(), async (request, response, next) => {
try {
for (const key of request.body.data.attributes.ids) {
const parts = key.split('|');
await azureTableStorageService.deleteEntityAsync(COLLECTION_NAME, parts[0], parts[1]);
}
response.status(204).send()
} catch (e) {
console.error(e);
next(e);
}
});
module.exports = router;

Result