Advanced filter is really fast and neat.
Here's a slower method, but it trains you in
logic and the use of conditional formulas.
If the data is in a table, first sort it by the
data column to be deduped (call it column D).
Let's say row 1 is field header and row 2 is
the first record. Use an If/Then statement:
[=IF(D3=D2,"Dupe","Okay")]
in the first available column (give it a field
header name, like "Dupe," to make it part
of the Table). Copy the formula all the way
down the column to the last record in the
table. Highlight the entire column (click the
gray cell in the column heading at the top)
and [Copy | Paste Special | Value].
If there are three dupes, the first will say:
Okay; the other two will say Dupe. Sort
the table by this new column and delete
all of the "Dupe" records.
If there are other considerations in other
parts of the record for determining which
record should be retained, then use a
nested If/Then statement to consider other
criteria. (You might have date fields and
need to retain the earliest customer contact.)
