Update query to fill in multiple blank fields

[speedracer1971]

I am having problems trying to structure an update query to look at 4 fields in a table and when a blank space is found in any of the fields to update that blank field and not overwrite any fields that currently have data in that record. Please help show me how to set the criteria to accomplish this.

 

[Pat Hartman]

Don't use any criteria. For each of the four fields, use an IIf() to set their values:

IIf(IsNull(fld1), "something", fld1)

IIf(IsNull(fld2), "something", fld2)