Subject UDF argument can't be query-parameter
Author Jeges Endre

I use the Firebird 1.0 release under Win2k with Delphi.

I tried something like this with TIBQuery in Delphi:

select myudf(:P0) from mytable

The SQL statement is generated runtime. The myudf has a CSTRING(20) input
argument and a float output returned by value, and works fine with
constants and table field values.

The Firebird returned with error Data Type unknown.

I tried the same on IB 6.01 and got the same result. Then I downloaded the
latest Firebird snapshot because I saw that this is a closed bug
(409769) on the sourceforge. Still nothing. Then I tried to set the
paramdatatype TIBQuery.ParambyName('P0').Datatype := ftString, but that
did'nt work also. Is there a solution?