Teradata UDF to Call External RESTful API? - sql

Question

We have a RESTful API which performs some rather sophisticated encryption functions. Our customer is using Teradata and they want to implement this API natively in their database.
The goal is to not store unencrypted values in the database but to make the unencrypted values available when queried.
There are more controls which will be wrapped around this process but in its simplest form, one way to use it is to create Teradata UDFs and use them in:
An After Insert trigger which takes the unencrypted value from the new row, passes it to the API, then takes the result and replaces the unencrypted value with the encrypted value returned by the API.
A view which takes the encrypted value, passes it to our API, and returns the decrypted value in the view result set.
Both the API payload and the returned values are formatted Json and the SQL/UDF will need to get an authentication token to access the API.
We are able to use the API in any number of applications outside of Teradata, including SQL Server, but cannot find documentation to show us how to do this in Teradata. Does anyone have any leads or examples of calling RESTful APIs from within a Teradata UDF?
ALTER FUNCTION [dbo].[GetProfile]
(
#maskProfile tinyint ,
#PolyId nvarchar(50)
)
RETURNS
#profileTable TABLE
(
SourceSystemKey nvarchar(100),
PolyId nvarchar(50),
FirstName nvarchar(100),
LastName nvarchar(100),
DateOfBirth datetime,
Gender nvarchar(10),
EmailAddress nvarchar(100),
PhoneNumber nvarchar(50),
KeyType nvarchar(100),
KeyValue nvarchar(100),
StreetAddress1 nvarchar(100),
StreetAddress2 nvarchar(100),
StreetAddress3 nvarchar(100),
StreetAddress4 nvarchar(100),
City nvarchar(100),
StateCode nvarchar(10),
PostalCode nvarchar(10),
County nvarchar(100),
Country nvarchar(100)
)
AS
BEGIN
DECLARE #method varchar(5)
DECLARE #url varchar(1000)
DECLARE #token nvarchar(2000)
DECLARE #params nvarchar(2000)
DECLARE #tokenResponse nvarchar(max)
DECLARE #profileResponse nvarchar(max)
DECLARE #profileJson nvarchar(max)
DECLARE #vaultUri nvarchar(100) = 'http://xxxxx'
SET #method='POST';
SET #url = #vaultUri + '/passthrough/api/auth/login';
SET #token=''
SET #params = '{"AccountId": "<account id>",' +
' "ApiKey": "<api key>"}';
select #tokenResponse = dbo.GetPostAPI(#method,#url,#token,#params)
set #token =
(SELECT * FROM OPENJSON(#tokenResponse, N'$.Data')
WITH (
[token] nvarchar(max) N'$.Token'
))
set #method = 'PUT';
set #url = #vaultUri + '/piivault/api/profiles/GetProfile';
set #params = '{
"Seed": 0,
"Ids": [
{ "Index": 0,
"PolyId": "' + #PolyId + '" } ]
}';
set #profileResponse = dbo.GetPostAPI(#method,#url,#token,#params) ;
select #profileJson = JSON_QUERY (#profileResponse, '$.Data.Profiles')
select #profileJson = SUBSTRING(#profileJson, 2, len(#profileJson) - 2)
insert into #profileTable
select top 1 *
from GetProfileAttributes(#profileJson)
RETURN
END
GO
```
```
ALTER function [dbo].[GetPostAPI]
(
#method varchar(5),
#url varchar(8000),
#token NVARCHAR(2000),
#params NVARCHAR(2000)
)
returns varchar(8000)
as
BEGIN
DECLARE #authHeader NVARCHAR(2000);
DECLARE #contentType NVARCHAR(64);
DECLARE #postData NVARCHAR(2000);
DECLARE #responseText NVARCHAR(2000);
DECLARE #responseXML NVARCHAR(2000);
DECLARE #ret INT;
DECLARE #status NVARCHAR(32);
DECLARE #statusText NVARCHAR(32);
DECLARE #internalToken INT;
SET #authHeader= 'Bearer ' + #token;
SET #contentType = 'application/json';
EXEC #ret = sp_OACreate 'WinHttp.WinHttpRequest.5.1', #internalToken OUT;
-- Send the request.
EXEC #ret = sp_OAMethod #internalToken, 'open', NULL, #method, #url, 'false';
EXEC #ret = sp_OAMethod #internalToken, 'setRequestHeader', NULL, 'Authorization', #authHeader;
if #ret <> 0
begin
set #ret = 'sp_OAMethod setRequestHeader failed'
end
EXEC #ret = sp_OAMethod #internalToken, 'setRequestHeader', NULL, 'Content-type', #contentType;
EXEC #ret = sp_OAMethod #internalToken, 'send', NULL, #params;
-- Handle the response.
EXEC #ret = sp_OAGetProperty #internalToken, 'status', #status OUT;
EXEC #ret = sp_OAGetProperty #internalToken, 'statusText', #statusText OUT;
EXEC #ret = sp_OAGetProperty #internalToken, 'responseText', #responseText OUT;
-- Close the connection.
EXEC #ret = sp_OADestroy #internalToken;
return #responseText
END
GO
```
```
ALTER view [dbo].[v_xxx]
as
select ff.*, profile.FirstName, profile.LastName, profile.EmailAddress
from ff_flights_Anonymized ff
cross apply GetProfile(0, ff.mileageplus_number_PolyId) profile
GO
`
```