Oooops sorry,

That'll teach me to cut and paste!!! ;)

It should read as I suspect you already know....

UPDATE [TableName] SET
[fieldname1] = CASE WHEN [fieldname1] IS NULL THEN 0 ELSE [fieldname1] END,
[fieldname2] = CASE WHEN [fieldname2] IS NULL THEN '' ELSE [fieldname2] END

Where fieldname1 is a numeric field and fieldname2 is a character field.

Regards

Ian