Import REST API in MS Access (Load JSON / SOAP XML)

Contents

Introduction

json to access logo

In this post, we will learn how to import REST API in MS Access (JSON or SOAP XML data).  We will use ODBC PowerPack to connect and query a JSON file / URL.

JSON stands for JavaScript Object Notation and it is an Open and Standard format to read an object with attributes and values.  JSON is replacing XML because it is faster to read data, it is easier to parse data, it does not require end tags, it is shorter and it can use arrays.

We will load the data using the ZappySys JSON / REST API driver and then import the data in Access. You can use similar techniques to load SOAP Data using XML / SOAP Driver.

 

Requirements

This article assumes the following requirements are met before you can follow the steps listed in this article.

  1. Make sure that Microsoft Access installed
  2. Also, the driver ODBC PowerPack installed

An introduction to Rest API and OData

In this example, we will use OData (Open Data Protocol) to consume REST API. REST API (Representational State Transfer Application Program Interface) allows handling the interoperability between computers and the internet.

In REST API we can handle web services in different formats. In this example, we will work with the Northwind example. The Northwind example is available in this URL:

  1. By default, the data is displayed in XML format. To show the data in JSON use this URL:
  2. There are collections of data like Categories, CustomerDemographic, Customers, Invoices, etc. For example, the following URL will show the data of the categories collection:
  3. In the next steps, we will use ZappySys drivers to connect to this URL and query using OData.

Configure ODBC DSN for ZappySys JSON Driver

ODBC driver can be accessed in two modes.

  1. Using DSN
  2. Without DSN (Supply direct Connection String e.g. DRIVER={ZappySys JSON Driver}; …….. )

In this article, we will use the DSN approach (User DSN). We will first add the ZappySys JSON Driver in the ODBC Data Source Administrator.

Follow these steps to accomplish the task:

  1. First, Windows search, write ODBC and select the ODBC Data sources (32 bits)
    Open ODBC Data source

    Open ODBC Data Source

  2. As a second step, in ODBC Data source Administrator press the Add button.
    Add ZappySys

    Add ZappySys

  3. In this step, create the new data source, select ZappySys ODBC Driver.
    add new zappysys

    Add new zappysys json driver

  4. Here we have several properties, write a data source name. In this example, the name will be ZappySys JSON to Excel.
  5. The Data Source (URL or file path) can specify the URL of the source or if it is a local file, you can specify the local path. In this example, the URL is:
    You can also specify a local file path as Data SourceFor a single file:  c:\data\myfile_1.json
    For multiple files: c:\data\myfile_*.json
  6. Configure the ODBC JSON Driver like this:
    Configure JSON Driver for REST API Call

    Configure JSON Driver for REST API Call

How to import REST API data to Access

  1. In MS Access, go to External Data Ribbon and select New Data Source and select From Other Sources and ODBC Database.
    Configuration in MS Access: Import Data From REST API

    A configuration in MS Access: Import Data From REST API

  2. Select the Source and destination of the data, select Import the source data into a new table in the current database and press OK.
    Get External Data - ODBC Database

    Get External Data – ODBC Database

  3. Select your newly created JSON Driver from the Machine Data Source and click OK.

    Get External Data - Select your newly created ODBC Data Source (JSON Driver)

    Get External Data – Select your newly created ODBC Data Source (JSON Driver)

     

     

  4. Select tables from the list of tables in the Import Objects screen and click OK.

    Get External Data - Select tables from Import Objects Screen

    Get External Data – Select tables from Import Objects Screen

  5. Select Save Import Steps from the screen and click on Save Import button.
    Get External Data - Select Save Import Steps

    Get External Data – Select Save Import Steps

  6. If everything is OK, you will be able to see the data.
    Data Imported Successfully in MS Access DB Table

    Data Imported Successfully in MS Access DB Table

How to link REST API data to Access

The linking process is very similar to importing data into the Access table. Follow steps of the previous paragraph – How to import REST API data to Access – but on step 2 select the second option to create a linked table instead. Then once asked to select a unique record identifier, don’t select anything:

Link table approach - don't select unique record identifier

Linked table approach – Don’t select a unique record identifier

REST API / XML SOAP Pagination Settings for MS Access

Even we set up ODBC Data Source to get the data, it may not be enough. Usually, if you are getting a huge data set from API provider, it won't give it to you in one HTTP response. Instead, it gives back only a subset of data and provides a mechanism for data pagination. The good news is that ZappySys ODBC Driver includes many options to cover virtually any pagination method.
Below you will find a few examples of API pagination. If you need something more sophisticated check the below link (the article was written for SSIS PowerPack but UI options and concepts apply to ODBC Driver too):

Paginate by Response Attribute

This example shows how to paginate API calls where you need to paginate until the last page detected. In this example, next page is indicated by some attribute called nextlink (found in response). If this attribute is missing or null then it stops fetching the next page.
SELECT * FROM $
WITH(
SRC=@'https://zappysys.com/downloads/files/test/pagination_nextlink_inarray_1.json'
,NextUrlAttributeOrExpr = '$.nextlink'  --keep reading until this attribute is missing. If attribute name contains dot then use brackets like this $.['my.attr.name']
)

Paginate by URL Parameter (Loop until certain StatusCode)

This example shows how to paginate API calls where you need to pass page number via URL. The driver keeps incrementing page number and calls next URL until the last page detected (401 error). There are few ways to indicate the last page (e.g. By status code, By row count, By response size). If you don't specify end detection then it will use the default (i.e. No records found).
SELECT * FROM $
WITH (
SRC=@'https://zappysys.com/downloads/files/test/page-xml.aspx?page=1&mode=DetectBasedOnResponseStatusCode'
,PagingMode='ByUrlParameter'
,PagingByUrlAttributeName='page'
,PagingByUrlEndStrategy='DetectBasedOnResponseStatusCode'
,PagingByUrlCheckResponseStatusCode=401
,IncrementBy=1
)

Paginate by URL Path (Loop until no record)

This example shows how to paginate API calls where you need to pass page number via URL Path. The driver keeps incrementing page number and calls next URL until the last page is detected. There are few ways to indicate the last page (e.g. By status code, By row count, By response size). If you don't specify end detection then it will use the default (i.e. No records found).
SELECT * FROM $
WITH (
SRC=@'https://zappysys.com/downloads/files/test/cust-<%page%>.xml'
,PagingMode='ByUrlPath'
,PagingByUrlAttributeName='<%page%>'
,PagingByUrlEndStrategy='DetectBasedOnRecordCount'
,IncrementBy=1
)

Paginate by Header Link (RFC 5988)

API like GitHub / Wordpress use Next link in Headers (RFC 5988)
SELECT * FROM $
LIMIT 25
WITH(
	 Src='https://wordpress.org/news/wp-json/wp/v2/categories?per_page=10'
	,PagingMode='ByResponseHeaderRfc5988'
	,WaitTimeMs='200' --//wait 200 ms after each request
)
 

REST API / SOAP Web Service Connection Settings for MS Access

If you need to authenticate or authorize your user to access a web resource, you will need to use one of the Connections:
  • HTTP
  • OAuth
ZappySys XML Driver - HTTP and OAuth Connection Types

HTTP Connection

Use HTTP Connection for simple Windows, Basic, NTLM or Kerberos authentication. Just fill in a username and a password and you are good to go!
You can also use HTTP Connection for more sophisticated authentication like:
  • SOAP WSS (when accessing a SOAP WebService)
  • Static Token / API Key (when need to pass an API key in HTTP header)
  • Dynamic Token (same as Static Token method except that each time you need to log in and retrieve a fresh API key)
  • JWT Token (As per RFC 7519)

OAuth

If you are trying to access REST API resource, it is a huge chance, you will need to use OAuth Connection. Read this article to understand how OAuth authentication and authorization works and how to use it (article originally was written for SSIS PowerPack, but the concepts and UI stay the same): https://zappysys.com/blog/rest-api-authentication-with-oauth-2-0-using-ssis

Other settings for REST API / SOAP XML Call in MS Access

There are few settings you can coder while calling Web API

API Limit / Throttling

While calling public API or other external web services one important aspect you have to check,  how many requests are allowed by your API. Especially when you use API pagination options to pull many records you have to slow down based on API limits. For example, your API may allow you only 5 requests per second. Use Throttling Tab on Driver UI to set delay after each request.

2D Array Transformation

If you are using JSON or XML API Driver then possible you may have to transform your data using 2D array transformation feature. Check this link for more information.  

REST API / XML SOAP Performance Tips for MS Access

While calling APIs you may face some performance issues. There are a few tips you can consider to speed up things.

Use Server-side filtering if possible in URL or Body Parameters

Many API supports filtering your data by URL parameters or via Body. Whenever possible try to use such features.  Here is an example of odata API, In the below query the first query is faster than the second query because in the first query we filter at the server.
SELECT * FROM value
WITH(
	 Src='http://services.odata.org/V3/Northwind/Northwind.svc/Customers?$format=json&$filter=Country eq ''USA'''
	,DataFormat='Odata'
)

-- Slow query - Client-side filtering
SELECT * FROM value
WHERE Country ='USA'
WITH(
	 Src='http://services.odata.org/V3/Northwind/Northwind.svc/Customers?$format=json'
	,DataFormat='Odata'
)

Avoid Special features in SQL Query (e.g. WHERE, Group By, Order By)

ZappySys API engine triggers client-side processing if special features are used in Query. Following SQL Features will trigger Client-Side processing which is several times slower than server-side processing. So always try to use simple query (Select col1, col2 .... from mytable )
  • WHERE Clause
  • GROUP BY Clause
  • HAVING Clause
  • ORDER BY
  • FUNCTIONS (e.g. Math, String, DateTime, Regex... )
LIMIT clause does not trigger client-side processing.

Consider using pre-generated Metadata / Cache File

Use META option in WITH Clause to use static metadata (Pre-Generated)There are two more options to speedup query processing time. Check this article for details.
  1. select * from value WITH( meta='c:\temp\meta.txt' )
    --OR--
    select * from value WITH( meta='my-meta-name' )
    --OR--
    select * from value WITH( meta='[ {"Name": "col1",&nbsp;"Type": "String", Length: 100},&nbsp;{"Name": "col2",&nbsp;"Type": "Int32"} ...... ]' )
  2. Enable Data Caching Options (Found on Property Grid > Advanced Mode Only )

Consider using Metadata / Data Caching Option

ZappySys API drivers support Caching Metadata and Data rows to speed up query processing. If your data doesn't change often then you can enable this option to speed up processing significantly. Check this article for details how to enable Data cache / metadata cache feature for datasource level or query level. To define cache option at query level you can use like below.
SELECT * FROM $
WITH 
(  SRC='https://myhost.com/some-api'
  ,CachingMode='All'  --cache metadata and data rows both
  ,CacheStorage='File' --or Memory
  ,CacheFileLocation='c:\temp\myquery.cache'
  ,CacheEntryTtl=300 --cache for 300 seconds
)
   

Use --FAST Option to enable Stream Mode

ZappySys JSON / XML drivers support --FAST suffix for Filter. By using this suffix after Filter driver enables Stream Mode, Read this article to understand how this works.
SELECT * FROM $ 
LIMIT 10 --//add this just to test how fast you can get 10 rows
WITH(
  Filter='$.LargeArray[*]--FAST' --//Adding --FAST option turn on STREAM mode (large files)
 ,SRC='https://zappysys.com/downloads/files/test/large_file_100k_largearray_prop.json.gz'
 --,SRC='c:\data\large_file.json.gz'
 ,IncludeParentColumns='False'  --//This Must be OFF for STREAM mode (read very large files)
 ,FileCompressionType='GZip' --Zip or None (Zip format only available for Local files)
)
 

Calling SOAP Web Service in MS Access

To call SOAP API you need to know Request XML Body Structure. If you are not sure how to create SOAP Request body then no worries. Check this article to learn how to generate SOAP Request body using the Free tool SoapUI. Basically, you have to use SoapUI to generate Request XML and after that, you can replace parameters as needed in the generated body.

What is SOAP Web Service?

If you are new to SOAP Web Service sometimes referred as XML Web Service then please read some concept about SOAP Web service standard from this link There are two important aspects in SOAP Web service.
  1. Getting WSDL file or URL
  2. Knowing exact Web Service URL

What is WSDL

In very simple term WSDL (often pronounced as whiz-dull) is nothing but a document which describes Service metadata (e.g. Functions you can call, Request parameters, response structure etc). Some service simply give you WSDL as xml file you can download on local machine and then analyze or sometimes you may get direct URL (e.g. http://api.mycompany.com/hr-soap-service/?wsdl )

Example SQL Query for SOAP API call using ZappySys XML Driver

Here is an example SQL query you can write to call SOAP API. If you not sure about many details then check next few sections on how to use XML Driver User Interface to build desired SQL query to POST data to XML SOAP Web Service without any coding.
SELECT * FROM $
WITH(
	 Src='http://www.holidaywebservice.com/HolidayService_v2/HolidayService2.asmx'
	,DataConnectionType='HTTP'
	,CredentialType='Basic' --OR SoapWss
	,SoapWssPasswordType='PasswordText'
	,UserName='myuser'
	,Password='pass$$w123'
	,Filter='$.soap:Envelope.soap:Body.GetHolidaysAvailableResponse.GetHolidaysAvailableResult.HolidayCode[*]'
	,ElementsToTreatAsArray='HolidayCode'	
	,RequestMethod='POST'	
	,Header='Content-Type: text/xml;charset=UTF-8 || SOAPAction: "http://www.holidaywebservice.com/HolidayService_v2/GetHolidaysAvailable"'
	,RequestData='
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:hol="http://www.holidaywebservice.com/HolidayService_v2/">
   <soapenv:Header/>
   <soapenv:Body>
      <hol:GetHolidaysAvailable>
         <!--type: Country - enumeration: [Canada,GreatBritain,IrelandNorthern,IrelandRepublicOf,Scotland,UnitedStates]-->
         <hol:countryCode>UnitedStates</hol:countryCode>
      </hol:GetHolidaysAvailable>
   </soapenv:Body>
</soapenv:Envelope>'
)
Now let's look at steps to create SQL query to call SOAP API. Later we will see how to generate code for your desired programming language (e.g. C# or SQL Server)

Video Tutorial - Introduction to SOAP Web Service and SoapUI tool

Before we dive into details about calling SOAP API using ZappySys XML Driver, lets first understand what is SOAP API and how to create SOAP requests using SoapUI tool. You will learn more about this process in the later section. The video contains some fragment about using SOAP API in SSIS but just ignore that part because we will be calling Soap API using ZappySys ODBC Driver rather than SSIS Components.  

Using SoapUI to test SOAP API call / Create Request Body XML

Assuming you have downloaded and installed SoapUI from here, now we are ready to use WSDL for your SOAP Web Service Calls. If you do not have WSDL file or URL handy then contact your API provider (sometimes you just have to add ?wsdl at the end of your Service URL to get WSDL so try that. Example: http://mycompany/myservice?wsdl ). If you don't know what is WSDL then in short, WSDL is Web service Description Language (i.e. XML file which describes your SOAP Service). WSDL helps to craft SOAP API request Body for ZappySys XML Driver. So Let's get started.
  1. Open SoapUI and click SOAP button to create new SOAP Project
  2. Enter WSDL URL or File Path of WSDLFor example WSDL for our sample service can be accessed via this URL
    http://www.holidaywebservice.com/HolidayService_v2/HolidayService2.asmx?wsdl
    Create new SOAP API Project in SoapUI tool for SOAP API Testing
    Create new SOAP API Project in SoapUI tool for SOAP API Testing
  3. Once WSDL is loaded you will see possible operations you can call for your SOAP Web Service.
  4. If your web service requires credentials then you have to configure it. There are two common credential types for public services (SOAP WSS or BASIC )
    1. To use SOAP WSS Credentials select request node and enter UserId, Password, and WSS-PasswordType (PasswordText or PasswordHash)
      Configure SOAP WSS Credentials for SoapUI (SOAP API Testing Tool)
      Configure SOAP WSS Credentials for SoapUI (SOAP API Testing Tool)
    2. To use BASIC Auth Credentials select request node and double-click it. At the bottom click on Auth (Basic) and From Authorization dropdown click Add New and Select Basic.Configure Basic Authorization for SoapUI (SOAP API Testing Tool)
      Configure Basic Authorization for SoapUI (SOAP API Testing Tool)
  5. Now you can test your request first Double-click on the request node to open request editor.
  6. Change necessary parameters, remove optional or unwanted parameters. If you want to regenerate request you can click on Recreate default request toolbar icon. Create SOAP Request XML (With Optional Parameters)
    Create SOAP Request XML (With Optional Parameters)
  7. Once your SOAP Request XML is ready, Click the Play button in the toolbar to execute SOAP API Request and Response will appear in Right side panel. Test SOAP API using SoapUI Tool (Change Default XML Body / Parameters, Execute and See Response) Test SOAP API using SoapUI Tool (Change Default XML Body / Parameters, Execute and See Response)

Create DSN using ZappySys XML Driver to call SOAP API

Once you have tested your SOAP API in SoapUI tool, we are ready to use ZappySys XML driver to call SOAP API in your preferred BI tool or Programming language.
  1. First open ODBC Data Sources (search ODBC in your start menu or go under ZappySys > ODBC PowerPack > ODBC 64 bit)
  2. Goto System DSN Tab (or User DSN which is not used by Service account)
  3. Click Add and Select ZappySys XML Driver ZappySys ODBC Driver for XML / SOAP API ZappySys ODBC Driver for XML / SOAP API
  4. Configure API URL, Request Method and Request Body as below ZappySys XML Driver - Calling SOAP API - Configure URL, Method, Body ZappySys XML Driver - Calling SOAP API - Configure URL, Method, Body
  5. (This step is Optional) If your SOAP API requires credentials then Select Connection Type to HTTP and configure as below. ZappySys XML Driver - Configure SOAP WSS Credentials or Basic Authorization (Userid, Password)
    ZappySys XML Driver - Configure SOAP WSS Credentials or Basic Authorization (Userid, Password)
  6. Configure-Request Headers as below (You can get it from Request > Raw tab from SoapUI after you test the request by clicking the Play button) Configure SOAP API Request Headers - ZappySys XML Driver Configure SOAP API Request Headers - ZappySys XML Driver
  7. Once credentials entered you can select Filter to extract data from the desired node. Make sure to select array node (see special icon) or select the node which contains all necessary columns if you don't have array node. Select Filter - Extract data from nested XML / SOAP API Response (Denormalize Hierarchy) Select Filter - Extract data from nested XML / SOAP API Response (Denormalize Hierarchy)
  8. If prompted select yes to treat selected node as Array (This is helpful when you expect one or more record for selected node) Treat selected node as XML Array Option for SOAP API Response XML Treat selected node as XML Array Option for SOAP API Response XML

Preview SOAP API Response / Generate SQL Code for SOAP API Call

Once you configure settings for XML Driver now you can preview data or generate example code for desired language (e.g. C#, Python, Java, SQL Server). Go to Preview tab and you will see default query generated based on settings you entered in previous sections. Attributes listed in WITH clause are optional. If you omit attribute in WITH clause it will use it from Properties tab.

Preview Data

Preview SOAP API Response in ZappySys XML Driver Preview SOAP API Response in ZappySys XML Driver

Generate Code Option

Generate Example Code for ZappySys Driver
Generate Example Code for ZappySys Driver

Conclusion

In this article, we learned how to use the ZappySys ODBC PowerPack to import JSON to Access. We used the OData protocol for Import data to Access.  With ZappySys ODBC Power Pack, you can query REST API information or JSON files using SQL and filter the information or write custom queries according to your needs.

References

Posted in JSON File / REST API Driver, ODBC Drivers, ODBC PowerPack, Reporting - Microsoft Access, XML File / SOAP API Driver and tagged , , , , , .