fix sending json with execute

[hpoul]

I tried to bind a json value but couldn't get it to work. After further inspection it looks like json only works for query but not for execute.

Because of some reason query uses native binding, while execute uses sendSimple

postgresql-dart/lib/src/connection_fsm.dart

Lines 198 to 201 in 1d74c21

	if (q.onlyReturnAffectedRowCount) {
	q.sendSimple(connection!._socket!);
	return _PostgreSQLConnectionStateBusy(q);
	}

I don't understand at all why there is a difference? Why use sendSimple for execute?

This PR is only to reproduce the bug. Please advise how to fix it? Does it make sense to try to support json in sendSimple or should everything use sendExtended?

the error message is:

PostgreSQLSeverity.error 42601: syntax error at or near "{" 

(I assume the CI should show that as well)

[isoos]

I think it is a good idea to have a test for it, and this issue should be fixed, however, it may not be a good idea to commit a test to CI that always fails. Let's add a skip: true to the test method, and some comments on why this test should pass (basically the info is already in the PR, but maybe better to copy-paste it into the test).

[hpoul]

@isoos ok I think I found a pretty easy fix after all 😅️

but the only reason I could come up with the difference between query and execute is that "simple queries" don't support multiple queries in one message..

https://www.postgresql.org/docs/current/protocol-flow.html#:~:text=The%20query%20string%20contained,complicate%20the%20protocol%20unduly.

The query string contained in a Parse message cannot include more than one SQL statement; else a syntax error is reported. This restriction does not exist in the simple-query protocol, but it does exist in the extended protocol, because allowing prepared statements or portals to contain multiple commands would complicate the protocol unduly.

Since this is actually a use case I use myself, I think it makes sense to have both options 😅️ (Unless the client library itself parses the message good enough to split queries).

But maybe it would make sense to have the option to do it nonetheless.. I see no reason why execute statements can't be cached (ie. prepared statements). maybe we could add a allowReuse to the execute method which switches to extended queries? Anyway.. that's obviously a separate issue 😅️

[isoos]

Fantastic finding! Thanks!