Making API calls

You can make restful API calls from your triggers and stored procedures like this:

	CALL parasql_http(
		'POST', -- enum: GET, POST, PUT, DELETE
		'https://www.mydomain.com/endpoint?param1=value1...', -- request URL
		JSON_OBJECT(...your post data...), -- optional request body in JSON format
		'MyCallback', -- optional callback procedure
		NULL, -- optional metadata in JSON format
		NULL); -- optional http headers in JSON format
	

The http request will be made after the calling transaction commits.
Results, including any errors, will be logged in the parasql_http_request table (see below). You should query this table for diagnostic information.
If you specify a callback procedure it will called with the following parameters:

respCode INTEGER, respBody JSON, respHeaders JSON, optMetadata JSON

Working with JSON data

There are a large number of functions available for parsing and generating data in JSON format. See the documentation here.

The most heavily used JSON functions are JSON_OBJECT() to create a JSON object and JSON_VALUE() to extract a value from a JSON document. You may also need JSON_LENGTH() to get the length of a JSON array.

HTTP Request Table

This table logs all HTTP request/response data. You can query it for diagnostic purposes.

parasql_http_request
Column Name	Datatype	Comments
id	BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY	Unique request identifier.
request_timestamp	DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP	Timestamp of request.
request_method	ENUM ('GET','POST','PUT','DELETE') NOT NULL DEFAULT 'GET'	Request method.
request_url	VARCHAR(2048) NOT NULL	The request URL.
request_headers	JSON	Optional. HTTP request headers in JSON format.
post_data	MEDIUMTEXT	Optional. Should be called request_body. If this value is NOT NULL then 1) a Content-Length header will be computed and added automatically and 2) a Content-Type header will be added based upon the post_data_encoding column value.
post_data_encoding	VARCHAR(255)	Optional. The Content-Type header if post_data is NOT NULL. Default is application/x-www-form-urlencoded if not specified. application/json is the most common alternative and the default for requests made via the parasql_http() procedure.
response_status	INT	HTTP response status code or -1 if an exception is thrown before a response is received.
response_headers	JSON	HTTP response headers in JSON format.
response_body	MEDIUMTEXT	HTTP response body or the exception text if response_status = -1
callback_procedure	VARCHAR(64)	Optional. The name of the stored procedure to be called for handling the response.
callback_status	VARCHAR(1024)	Result of callback execution: either COMMIT or ROLLBACK with an associated error message.
opt_metadata	JSON	Optional. User defined metadata. Useful for linking request/response behavior and diagnostic purposes.
version	INT	Internal version number. Determines how request/response parameters are processed.