SQL datatype comparison help

[rh71]

field used to be comparing varchar to char such as this and it worked ok:
WHERE firstname = username

now the field is comparing long varchar vs. char:
WHERE thefullname = username

and it's returning this error:
Improper use of a string column, host variable, constant, or
function "". SQLSTATE=42907

Is there any way I can still compare these two fields ? It must be these fields so maybe some kind of conversion function on either of them would work ?

Thanks

 

[Lint21]

Did you try casting the char as a varchar?

where thefullname = cast(username as varchar)

I don't know if that's the problem, though. This could be something different, but I'm not sure what.

 

[rh71]

thanks but the cast function created the following error:

SQL0604N The length, precision, or scale attribute for column, distinct type,
structured type, attribute of structured type, function, or type mapping "" is
not valid. SQLSTATE=42611

 

[stndn]

i believe you need to quote the value in strings?
WHERE thefullname = 'username'

don't think the varchar or char matters....