If you have a variable say "class" or "package" when calling them via a script you will get weird results. I'd advise to avoid this list of names for columns.

Javascript Reserved Words

abstract arguments await boolean break byte case catch
char class const continue debugger default delete do
double else enum eval export extends false final
finally float for function goto if implements import
in instanceof int interface let long native new
null package private protected public return short static
super switch synchronized this throw throws transient true
try typeof var void volatile while with yield

Try it out. make a catalog item. make a variable, call it "class", try to use that variable in a refernce qualifer and observe weird things.

The docs also say, "you cannot use reserved words".

Other's have had issues using these terms for column names. If you can, avoid that so you don't have the same problem here as Detlef.

MysQL Reserved Words

Database view reserved words seems to be different and dependent on MysQL's list