The Utils\run_mysql_command() function currently just lets the mysql binary dump its output into STDOUT by default.

Although it allows for providing an alternative set of descriptors, it doesn't provide the means to get a hold of the pipes before the process is closed again, thus making this useless. I assume that having the $descriptors as an argument in the first place was an oversight, as they can't actually be used in that form.

It would be preferable to have a simple method of getting access to $stdout and $stderr streams if needed, and just dump to STDOU /STDERR` if not.

This is required for:

• Output single column from db query without formatting db-command#145
• Adapt SQL mode to account for WordPress incompatibilities db-command#168