Help with counting unique alphanumeric codes in same field
Hello Forum - I am Curator of archaeological collections. We have a box inventory, and sometimes artifacts from many different sites in the same box. One record per box. Site numbers are alphanumeric, e.g., 11MO80 or 11S2258 (two-digit number, one or two letters, then a number). If multiple site numbers are in the same field, how do I count the number of unique site numbers in the database? I don't want to count a site number twice. I assume some type of IF THEN operator is involved, but I don't know what to do. Any help is appreciated.