How to call a REST API with PL/SQL

Answer:

Here are the general steps on how to call a REST API using PL/SQL:

1. Register the REST API: First thing you must do is to let Oracle know that a REST service exists and is available. You can define your REST service with Oracle using the APEX_WEB_SERVICE package.

2. Create a HTTP request to call the REST API: Once the REST API is registered in Oracle, you can use the UTL_HTTP package to create a HTTP request to call the REST API.

Here's a simple example of what code might look like:

DECLARE
l_url VARCHAR2(500);
l_response CLOB;
l_http_request UTL_HTTP.req;
l_http_response UTL_HTTP.resp;
BEGIN
--Define API url
l_url := 'http://<api_url>';

-- Make a HTTP request to the REST API
l_http_request := UTL_HTTP.begin_request(l_url, 'POST', 'HTTP/1.1');

-- Set Header parameters
UTL_HTTP.set_header(l_http_request, 'Content-Type', 'application/x-www-form-urlencoded');

-- Send Request and get Response
l_http_response := UTL_HTTP.get_response(l_http_request);

-- Get the JSON response
UTL_HTTP.read_text(l_http_response, l_response);

UTL_HTTP.end_response(l_http_response);
EXCEPTION
WHEN utl_http.end_of_body THEN
dbms_output.put_line('Response:'||l_response);
WHEN OTHERS THEN
dbms_output.put_line('Error in http request:'||SQLERRM);
END;
/


Disclaimer: You need to replace '<api_url>' with your actual REST API URL.
Also, error handling and security considerations like SSL certificate, handling sensitive information etc., should be properly implemented.

Keep in mind that network ACLs have to be properly configured so PL/SQL can reach network resources. Also, don't forget to handle any potential exceptions.

Please note, in Oracle 19c and above you can also use the DBMS_CLOUD package to send HTTP requests, which can simplify the code significantly if you are working in the Oracle Cloud.