This is for sake of others... I just spent a long time in rabbit holes to figure this out. I was upgrading an old system, including newer versions of PHP, MySQL, and shifting to Xataface 3.x. I had two different databases, each with its own interface, etc. Both had some challenges to overcome for proper CSS and display. Then I went to log in to make some edits. One worked fine, the other threw errors with the login.
"Exception: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '('myPassword')' at line 3 in /...../xataface-3.0.4/Dataface/AuthenticationTool.php:446\nStack trace:\n#0 /....../xataface-3.0.4/Dataface/AuthenticationTool.php(619)"
[password]
encryption=[your choice of function]
Rather, it was in my /tables/Users/fields.ini as
[my password field]
encryption=[your choice of function]
and one database had that set as PASSWORD for my choice. But that is no longer a viable option.
I haven't done much work with Xataface coding lately (or SQL), so it took me a while to find that.
Have a great day!