Microsoft Office Tutorials and References
In Depth Information
Finding Duplicate Records in the Table (and Removing Them)
available; in Figure 7–33, in which we’ve clicked in a text field, we’ll be able to tally a
count of the number of last names in the table column. Click the down arrow by Salary
and you can select a different calculation—say, an average. If you decide you need to
add additional records to the table, you can click the Total Row check box a second time
to remove it. You can then continue adding records.
Finding Duplicate Records in the Table (and Removing
A classic data entry problem, one particularly besetting large databases, is the specter
of duplicate records. It’s not uncommon to discover the same names appearing
repeatedly in large lists, and if you’re the person charged with maintaining the database,
you’ll need to do something about it. Excel’s tables are equipped with a Remove
Duplicates feature, which speeds the task of winnowing those doubles from the data.
The first order of business in removing duplicates is deciding exactly what constitutes a
duplicate. After all, Jane Walsh and John Walsh share a last name, but you’re not likely
to declare them duplicate entries. What you usually want to sift out are entire records
that are identical—that is, two John Walshes—although it always isn’t that simple. J.
Walsh and John Walsh, both of whom record an address of 123 Broadway, might very
well qualify as duplicates, too.
To see how Excel helps you with
this task, pick out an empty area of
the worksheet and enter the simple
database shown in Figure 7–34.
Remember that the size of the
database is irrelevant. The Remove
Duplicates options works the same
way in every case.
Figure 7–34. Double take: Searching for duplicates
Then convert the database to a table. Note that the “My table has
headers” check box won't be checked, and that’s because all the data
in the database, including that in the top row, is text, so Excel can’t tell if
there’s anything special or different about that top row. We thus need to
tick the check box in order to let Excel know that we do want a header