Question about NULL's

<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> Hi, <br>I have the following problem: A table in my database has some constraint checks. There are also fields with only one space in it (' '). The output from dbschema is quite correct. <br>Output from dbschema: <br>... <br>&nbsp;&nbsp;&nbsp; check (benz IN ('N' ,'S' ,'D' ,'B' ,'P' ,' ' )), <br>&nbsp;&nbsp;&nbsp; check (kat IN ('G' ,'U' ,' ' )), <br>&nbsp;&nbsp;&nbsp; check (heck IN ('F' ,'S' ,'G' ,'W' ,' ' ,'L' )), <br>&nbsp;&nbsp;&nbsp; check (antr IN ('A' ,'V' ,'H' ,' ' )), <br>&nbsp;&nbsp;&nbsp; check (blei IN ('B' ,' ' )), <br>&nbsp;&nbsp;&nbsp; check (moto IN ('O' ,'D' ,'R' ,'Z' ,' ' )), <br>&nbsp;&nbsp;&nbsp; check (abga IN ('1' ,'2' ,'A' ,'B' ,'C' ,' ' )), <br>... <p>But - if I test the same table in dbaccess (Info - Constraint -Checks) I get the following: <br>Output from inside dbaccess: <br>Constraint name&nbsp;&nbsp;&nbsp; Value <br>c928_8451&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (benz IN ('N' ,'S' ,'D' ,'B' ,'P' ,' ' )) <br>c928_8453&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (kat IN ('G' ,'U' ,' ' )) <br>c928_8469&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (heck IN ('F' ,'S' ,'G' ,'W' ,'' ,'L' )) <br>c928_8477&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (antr IN ('A' ,'V' ,'H' ,' ' )) <br>c928_8482&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (blei IN ('B' ,' ' )) <br>c928_8484&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (moto IN ('O' ,'D' ,'R' ,'Z' ,'' )) <br>c928_8493&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (abga IN ('1' ,'2' ,'A' ,'B' ,'C' ,' ' )) <p>Note, that some fields have the ''-value - that's a NULL!!! But I don't want have NULLs in my tables! How can I correct this? <p>R. Heydenreich</html>