Re: SQL COBOL to Consume REST APIs

[Roman Miklos <rmiklos.work@xxxxxxxxx>]

Hi Kelly Cookson,

Yes, we did it a few years ago: we called relatively simple REST GET APIs
via embedded SQL.

Recently, however, since we also program in Java, we prefer the following
option: write a SQL UDTF in Java and then call it from the COBOL program
via embedded SQL. Working with JSON from Java is much more comfortable than
with SQL JSON functions. Especially if something goes wrong, you can test
the SQL UDTFs separately and it is easier to find the error debugging Java
code of the UDTF. Finding a bug in ESQL is sometimes painful. It is often
necessary to first extract the SQL statements from the COBOL program and
elaborate with them to determine that in the REST API a field in the output
JSON has been renamed.
And if you need to call multiple REST APIs, I think the Java UDTF solution
is far superior. In ESQL with JSON Functions it would be very complicated.

Regards
Roman

On Wed, Feb 9, 2022 at 4:07 PM Kelly Cookson via COBOL400-L <
cobol400-l@xxxxxxxxxxxxxxxxxx> wrote:

> Hi,
>
> I am looking for a way to develop a REST API client with COBOL. I know it
> can be done with RPG. But I want to know if it can be done with COBOL.
>
> Is it possible for a COBOL program to use embedded SQL to do the following?
>
> 1. Use the new QSYS2 HTTP functions to consume a REST API. (Needs to be
> the new QSYS2 functions and not the old SYSTOOLS functions.)
>
> 2. Use the SQL function JSON_TABLE to get the data from the JSON returned
> by the REST API.
>
> I am not asking for examples. I just want to know if anyone has already
> done this, so I know it is possible. Or know if it is not possible and not
> waste my time trying.
>
> Thanks,
>
> Kelly Cookson
> Senior Software Engineer II
> Dot Foods, Inc.
> 1-217-773-4486  ext. 12676
> www.dotfoods.com<http://www.dotfoods.com>
>
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