phpstom false error when concatenated sql string

Hi there,

I may suggest this:

$sql = "INSERT INTO ..."
 . "VALUES (...)";

P.S. What is wrong with HEREDOC? The delimiter indent? As of PHP 7.3 you can have flexible indented delimiter (https://wiki.php.net/rfc/flexible_heredoc_nowdoc_syntaxes)

I'll take this as "there is none"
regarding HEREDOC backward compatibility 

Looks like it.

https://youtrack.jetbrains.com/issue/WI-18915 I guess