How to create a custom REST API connector for PowerShell

Learn how to quickly and efficiently connect Custom API with PowerShell for smooth data access.

Read / write Custom API data without coding. You can do it all using the high-performance Custom API ODBC Driver for PowerShell (often referred to as the Custom API Connector). We'll walk you through the entire setup.

Ready to dive in? Download the product to jump right in, or follow the step-by-step guide below to see how it works.

Create Custom API Connector

First of all, you will have to create your own API connector. For demonstration purposes, in this section we will create a simple Hello-World API connector that calls ZappySys Sandbox World API endpoint https://sandbox.zappysys.com/api/world/hello. When developing your Custom API Connector, just replace it with your real API method/endpoint. Let's dive in and follow these steps:

1. Search for odbc and open the ODBC Data Sources (64-bit):

   

2. Create a User data source (User DSN) based on the ZappySys JSON Driver driver:

   ZappySys JSON Driver

   

3. Once the data source configuration window opens, enter this URL into the text box:

   https://sandbox.zappysys.com/api/world/hello

   

4. Then go to the Preview tab and try to say "Hello!" to the World!

   

5. Since the test is successful, you are ready to create the Hello-World Connector:

   

6. The API Connector File Wizard opens, click Next:

   

7. Leave the default option, and click Next again:

   

8. Just click Next in the next window:

   

9. Let's give our new custom connector a name it deserves:

   

10. Then just click Next in the Connection Types window:

    

11. Let's name the hello endpoint (it deserves a name too!):

    

12. When the next window opens, delete the default table (we won't need it for now):

    

13. Finally, specify a path, where you want to save the newly created API Connector:

    

Create data source using Custom API ODBC Driver

Step-by-step instructions

To get data from Custom API using PowerShell, we first need to create an ODBC data source. We will later read this data in PowerShell. Perform these steps:

1. Download and install ODBC PowerPack (if you haven't already).

2. Search for odbc and open the ODBC Data Sources (64-bit):

   

3. Create a User data source (User DSN) based on the ZappySys API Driver driver:

   ZappySys API Driver

   

4. When the Configuration window appears give your data source a name if you haven't done that already. Then set the path to your created Custom API Connector (in the example below, we use Hello-World Connector). Finally, click Continue >> to proceed:

   

5. Now it's time to configure the Connection Manager. Select Authentication Type, e.g. Token Authentication. Then select API Base URL (in most cases, the default one is the right one). Check your Custom API reference for more information on how to authenticate.

   

6. Once the data source connection has been configured, it's time to configure the SQL query. Select the Preview tab and then click Query Builder button to configure the SQL query:

   

   ZappySys API Driver - Custom API

   Read / write Custom API data without coding.

   CustomApiDSN

   

7. Start by selecting the Table or Endpoint you are interested in and then configure the parameters. This will generate a query that we will use in PowerShell to retrieve data from Custom API. Hit OK button to use this query in the next step.

   SELECT * FROM Orders

   
   Some parameters configured in this window will be passed to the Custom API, e.g. filtering parameters. It means that filtering will be done on the server side (instead of the client side), enabling you to get only the meaningful data much faster.

8. Now hit Preview Data button to preview the data using the generated SQL query. If you are satisfied with the result, use this query in PowerShell:

   

   ZappySys API Driver - Custom API

   Read / write Custom API data without coding.

   CustomApiDSN

   SELECT * FROM Orders

   
   You can also access data quickly from the tables dropdown by selecting <Select table>.
   A WHERE clause, LIMIT keyword will be performed on the client side, meaning that the whole result set will be retrieved from the Custom API first, and only then the filtering will be applied to the data. If possible, it is recommended to use parameters in Query Builder to filter the data on the server side (in Custom API servers).

9. Click OK to finish creating the data source.

Video Tutorial

Read Custom API data in PowerShell

Sometimes, you need to quickly access and work with your Custom API data in PowerShell. Whether you need a quick data overview or the complete dataset, this article will guide you through the process. Here are some common scenarios:

• Quickly peek at Custom API data
• Monitor data constantly in your console

• Export data to a CSV file so that it can be sliced and diced in Excel
• Export data to a JSON file so that it can ingested by other processes
• Export data to an HTML file for user-friendly view and easy sharing
• Create a schedule to make it an automatic process

• Store data internally for analysis or for further ETL processes
• Create a schedule to make it an automatic process

• Integrate data with other systems via external APIs

In this article, we will delve deeper into how to quickly view the data in PowerShell terminal and how to save it to a file. But let's stop talking and get started!

Reading individual fields

1. Open your favorite PowerShell IDE (we are using Visual Studio Code).

2. Use this code snippet to read the data using CustomApiDSN data source:

   "DSN=CustomApiDSN"

   

   For your convenience, here is the whole PowerShell script:

   # Configure connection string and query
   $connectionString = "DSN=CustomApiDSN"
   $query = "SELECT * FROM Customers"
   
   # Instantiate OdbcDataAdapter and DataTable
   $adapter = New-Object System.Data.Odbc.OdbcDataAdapter($query, $connectionString)
   $table = New-Object System.Data.DataTable
   
   # Fill the table with data
   $adapter.Fill($table)
   
   # Since we know we will be reading just 4 columns, let's define format for those 4 columns, each separated by a tab
   $format = "{0}`t{1}`t{2}`t{3}"
   
   # Display data in the console
   foreach ($row in $table.Rows)
   {
       # Construct line based on the format and individual Custom API fields
       $line = $format -f ($row["CustomerId"], $row["CompanyName"], $row["Country"], $row["Phone"])
       Write-Host $line
   }
   

   Access specific Custom API table field using this code snippet:

   $field = $row["ColumnName"]

   You will find more info on how to manipulate DataTable.Rows property in Microsoft .NET reference.
   For demonstration purposes we are using sample tables which may not be available in Custom API.

3. To read values in a console, save the script to a file and then execute this command inside PowerShell terminal:

   
   You can also use even a simpler command inside the terminal, e.g.:

   . 'C:\Users\john\Documents\dsn.ps1'

Retrieving all fields

However, there might be case, when you want to retrieve all columns of a query. Here is how you do it:

"DSN=CustomApiDSN"

Again, for your convenience, here is the whole PowerShell script:

# Configure connection string and query
$connectionString = "DSN=CustomApiDSN"
$query = "SELECT CustomerId, CompanyName, Country, Phone FROM Customers"

# Instantiate OdbcDataAdapter and DataTable
$adapter = New-Object System.Data.Odbc.OdbcDataAdapter($query, $connectionString)
$table = New-Object System.Data.DataTable

# Fill the table with data
$adapter.Fill($table)

# Display data in the console
foreach ($row in $table.Rows) {
    $line = ""
    foreach ($column in $table.Columns) {
        $value = $row[$column.ColumnName]

        # Let's handle NULL values
        if ($value -is [DBNull])
        {
            $value = "(NULL)"
        }
        $line += $value + "`t"
    }
    Write-Host $line
}

SELECT * FROM Customers LIMIT 10

Using a full ODBC connection string

In the previous steps we used a very short format of ODBC connection string - a DSN. Yet sometimes you don't want a dependency on an ODBC data source (and an extra step). In those times, you can define a full connection string and skip creating an ODBC data source entirely. Let's see below how to accomplish that in the below steps:

1. Open ODBC data source configuration and click Copy settings:
   

   ZappySys API Driver - Configuration [Version: 2.0.1.10418]

   ZappySys API Driver - Custom API

   Read / write Custom API data without coding.

   CustomApiDSN

   
2. The window opens, telling us the connection string was successfully copied to the clipboard:
3. Then just paste the connection string into your script:
4. You are good to go! The script will execute the same way as using a DSN.

Handling limitations of using a full connection string

Despite using a full ODBC connection string may be very convenient it comes with a limitation: it's length is limited to 1024 symbols (or sometimes more). It usually happens when API provider generates a very long Refresh Token when OAuth is at play. If you are using such a long ODBC connection string, you may get this error:

"Connection string exceeds maximum allowed length of 1024"

But there is a solution to this by storing the full connection string in a file. Follow the steps below to achieve this:

1. Open your ODBC data source.
2. Click Copy settings button to copy a full connection string (see the previous section on how to accomplish that).
3. Then create a new file, let's say, in C:\temp\odbc-connection-string.txt.
4. Continue by pasting the copied connection string into a newly created file and save it.
5. Finally, the last step! Just construct a shorter ODBC connection string using this format:

   DRIVER={ZappySys API Driver};SettingsFile=C:\temp\odbc-connection-string.txt

6. Our troubles are over! Now you should be able to use this connection string in PowerShell with no problems.

Write Custom API data to a file in PowerShell

Save data to a CSV file

Export data to a CSV file so that it can be sliced and diced in Excel:

# Configure connection string and query
$connectionString = "DSN=CustomApiDSN"
$query = "SELECT * FROM Customers"

# Instantiate OdbcDataAdapter and DataTable
$adapter = New-Object System.Data.Odbc.OdbcDataAdapter($query, $connectionString)
$table = New-Object System.Data.DataTable

# Fill the table with data
$adapter.Fill($table)

# Export table data to a file
$table | ConvertTo-Csv -NoTypeInformation -Delimiter "`t" | Out-File "C:\Users\john\saved-data.csv" -Force

Save data to a JSON file

Export data to a JSON file so that it can ingested by other processes (use the above script, but change this part):

# Export table data to a file
$table | ConvertTo-Json | Out-File "C:\Users\john\saved-data.json" -Force

Save data to an HTML file

Export data to an HTML file for user-friendly view and easy sharing (use the above script, but change this part):

# Export table data to a file
$table | ConvertTo-Html | Out-File "C:\Users\john\saved-data.html" -Force

Optional: Centralized data access via ZappySys Data Gateway

In some situations, you may need to provide Custom API data access to multiple users or services. Configuring the data source on a Data Gateway creates a single, centralized connection point for this purpose.

This configuration provides two primary advantages:

• Centralized data access
  The data source is configured once on the gateway, eliminating the need to set it up individually on each user's machine or application. This significantly simplifies the management process.
• Centralized access control
  Since all connections route through the gateway, access can be governed or revoked from a single location for all users.

To achieve this, you must first create a data source in the Data Gateway (server-side) and then create an ODBC data source in PowerShell (client-side) to connect to it.

Let's not wait and get going!

Create Custom API data source in the gateway

In this section we will create a data source for Custom API in the Data Gateway. Let's follow these steps to accomplish that:

1. Search for gateway in the Windows Start Menu and open ZappySys Data Gateway Configuration:

   

2. Go to the Users tab and follow these steps to add a Data Gateway user:

   • Click the Add button
   • In the Login field enter a username, e.g., john
   • Then enter a Password
   • Check the Is Administrator checkbox
   • Click OK to save
   

3. Now we are ready to add a data source:

   • Click the Add button
   • Give the Data source a name (have it handy for later)
   • Then select Native - ZappySys API Driver
   • Finally, click OK
   CustomApiDSN

   ZappySys API Driver

   

4. When the ZappySys API Driver configuration window opens, go back to ODBC Data Source Administrator where you already have the Custom API ODBC data source created and configured, and follow these steps on how to Import data source configuration into the Gateway:

   • Open ODBC data source configuration and click Copy settings:
     

     ZappySys API Driver - Configuration [Version: 2.0.1.10418]

     ZappySys API Driver - Custom API

     Read / write Custom API data without coding.

     CustomApiDSN

     
   • The window opens, telling us the connection string was successfully copied to the clipboard:

   • Then go to Data Gateway configuration and in data source configuration window click Load settings:

     CustomApiDSN

     

     ZappySys API Driver - Configuration [Version: 2.0.1.10418]

     ZappySys API Driver - Custom API

     Read / write Custom API data without coding.

     CustomApiDSN

     
   • Once a window opens, just paste the settings by pressing CTRL+V or by clicking right mouse button and then Paste option.

5. Once done, go to the Network Settings tab and Add a firewall rule for inbound traffic:

   
   • This will initially allow all inbound traffic.
   • Click Edit IP filters to restrict access to specific IP addresses or ranges.

6. Crucial Step: After creating or modifying the data source, you must:

   • Click the Save button to persist your changes.
   • Hit Yes when prompted to restart the Data Gateway service.

   This ensures all changes are properly applied:

   
   Skipping this step may cause the new settings to fail, preventing you from connecting to the data source.

Create ODBC data source to connect to the gateway

In this part we will create an ODBC data source to connect to the ZappySys Data Gateway from PowerShell. To achieve that, let's perform these steps:

1. Search for odbc and open the ODBC Data Sources (64-bit):

   

2. Create a User data source (User DSN) based on the ODBC Driver 17 for SQL Server driver:

   ODBC Driver 17 for SQL Server

   
   If you don't see the ODBC Driver 17 for SQL Server driver in the list, choose a similar version.

3. Then set a Name for the data source (e.g. Gateway) and the address of the Data Gateway:

   ZappySysGatewayDSN

   localhost,5000

   
   Make sure you separate the hostname and port with a comma, e.g. localhost,5000.

4. Proceed with the authentication part:

   • Select SQL Server authentication
   • In the Login ID field enter the user name you created in the Data Gateway, e.g., john
   • Set Password to the one you configured in the Data Gateway
   

5. Then set the default database property to CustomApiDSN (the one we used in the Data Gateway):

   CustomApiDSN

   CustomApiDSN

   
   Make sure to type the data source name manually or copy/paste it directly into the field. Using the dropdown might fail because the Trust server certificate option is not enabled yet (next step).

6. Continue by checking the Trust server certificate option:

   

7. Once you do that, test the connection:

   

8. If the connection is successful, everything is good:

   

9. Done!

We are ready to move to the final step. Let's do it!

Access data in PowerShell via the gateway

Finally, we are ready to read data from Custom API in PowerShell via the Data Gateway. Follow these final steps:

1. Go back to PowerShell.

2. Use this code snippet to read the data using ZappySysGatewayDSN data source:

   "DSN=ZappySysGatewayDSN"

   

   For your convenience, here is the whole PowerShell script:

   # Configure connection string and query
   $connectionString = "DSN=ZappySysGatewayDSN"
   $query = "SELECT * FROM Customers"
   
   # Instantiate OdbcDataAdapter and DataTable
   $adapter = New-Object System.Data.Odbc.OdbcDataAdapter($query, $connectionString)
   $table = New-Object System.Data.DataTable
   
   # Fill the table with data
   $adapter.Fill($table)
   
   # Since we know we will be reading just 4 columns, let's define format for those 4 columns, each separated by a tab
   $format = "{0}`t{1}`t{2}`t{3}"
   
   # Display data in the console
   foreach ($row in $table.Rows)
   {
       # Construct line based on the format and individual Custom API fields
       $line = $format -f ($row["CustomerId"], $row["CompanyName"], $row["Country"], $row["Phone"])
       Write-Host $line
   }
   

   Access specific Custom API table field using this code snippet:

   $field = $row["ColumnName"]

   You will find more info on how to manipulate DataTable.Rows property in Microsoft .NET reference.
   For demonstration purposes we are using sample tables which may not be available in Custom API.

3. Read the data the same way we discussed at the beginning of this article.

4. That's it!

Now you can connect to Custom API data in PowerShell via the Data Gateway.

Conclusion

In this article we showed you how to connect to Custom API in PowerShell and integrate data without writing complex code — all of this was powered by Custom API ODBC Driver.

Download ODBC PowerPack now or ping us via chat if you have any questions or are looking for a specific feature (you can also reach out to us by submitting a ticket):

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