Versuch mal folgendes:
Code:
 /Free
   Exec SQL
       update tabelle 
          set spalte = NULLIF(:hostvar, '');
oder

Code:
D HostVarInd      S            5I 0
 /Free
    If HostVar <= ' ';
       HostVarInd = -1;
    Else;
       HostVarInd = *Zeros;
    EndIf;

    Exec SQL Update Table
                Set Spalte = :HostVar :HostVarInd;
 /End-Free
Birgitta