Compares its string (varchar) arguments a and
b, returning -1 if a is less than b, 0 if they
are equal, or 1 if a is greater than b:
stringcompare(a, b[, mode])
The strings are compared using the optional mode argument,
which is a string-folding mode in the same format as
<apicp stringcomparemode>; see the Vortex manual for details on
the syntax and default. If mode is unspecified, the current
apicp stringcomparemode setting is used. Function added
in version 6.00.1304108000 20110429.