Node.js からCSV Data をクエリ

API Server は、データを外部に公開します。CData API Server のOData エンドポイントを使って、Node.js からCSV data へのCRUD クエリを実行します。

CData API Server とADO.NET Provider for CSV(もしくは200+ の他のADO.NET Providers)を使って、CSV をOData エンドポイントして公開し、Node.js からシンプルなHTTP リクエストでクエリを実現します。本記事ではAPI Server を使ってJSON でフォーマットされたCSV データをNode.js でリクエストする方法を説明します。

Set Up the API Server

Follow the steps below to begin producing secure CSV OData services:

Deploy

The API Server runs on your own server. On Windows, you can deploy using the stand-alone server or IIS. On a Java servlet container, drop in the API Server WAR file. See the help documentation for more information and how-tos.

The API Server is also easy to deploy on Microsoft Azure, Amazon EC2, and Heroku.

Connect to CSV

After you deploy the API Server and the ADO.NET Provider for CSV, provide authentication values and other connection properties needed to connect to CSV by clicking Settings -> Connections and adding a new connection in the API Server administration console.

The DataSource property must be set to a valid local folder name.

Also, specify the IncludeFiles property to work with text files having extensions that differ from .csv, .tab, or .txt. Specify multiple file extensions in a comma-separated list. You can also set Extended Properties compatible with the Microsoft Jet OLE DB 4.0 driver. Alternatively, you can provide the format of text files in a Schema.ini file.

Set UseRowNumbers to true if you are deleting or updating in CSV. This will create a new column with the name RowNumber which will be used as key for that table.

You can then choose the CSV entities you want to allow the API Server access to by clicking Settings -> Resources.

Authorize API Server Users

After determining the OData services you want to produce, authorize users by clicking Settings -> Users. The API Server uses authtoken-based authentication and supports the major authentication schemes. Access can also be restricted based on IP address; all IP addresses except the local machine are restricted by default. You can authenticate as well as encrypt connections with SSL.

Consume CSV OData Feeds from Node.js

OData feeds are easy to work with in Node.js. You can use the HTTP client in Node.js to request JSON-formatted data from the API Server's OData endpoint. After making the request, you can construct the body of the response and call the JSON.parse() function to parse it into records.

The code below will make an authenticated request for Customer data. The example URL below applies a simple filter that searches for records with a value of Bob in the FirstName column.

var http = require('http'); http.get({ protocol: "http:", hostname: "MyServer.com", port: MyPort, path: "/api.rsc/Customer?$filter=" + encodeURIComponent("FirstName eq 'Bob'"), auth: 'MyUser:MyAuthtoken' }, function(res) { var body = ''; res.on('data', function(chunk) { body += chunk; }); res.on('end', function() { console.log(body); var jsonData = JSON.parse(body); }); }).on('error', function(e) { console.log("Error: ", e); });
 
 
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