Microsoft Office

Using Microsoft Query with
External Database Files
Excel has some great analysis and presentation tools, but these tools require
data. In many cases, the data that you need is available in an external
database. For example, your company may have a database that contains
customer information, sales data, and so on. This chapter is an introduction to
retrieving data from external database files for use in Excel.
Understanding External
Database Files
IN THIS CHAPTER
Understanding external database
files
Getting started using Microsoft
Query
Working with external data
When you work with an Excel workbook, the entire workbook must be loaded
into memory before you can begin working. Although loading all the data provides
you with immediate access to the entire file and all the data it contains, it
also means that you can’t work with extremely large amounts of data. Although
Excel 2007 supports more than a million rows, actually using that many rows
can slow your system to a crawl — even if your system has plenty of memory.
When you access an external database file using Excel, you can perform a query
to load just a subset of the data into your workbook.
Accessing external database files from Excel is useful in the following situations:
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You need to work with a subset of a very large database.
You share the database with others; that is, other users have access to
the database and may need to work with the data at the same time.
The database is in a format that Excel can’t import, or the database may
be too large to import.
The database contains multiple tables with relationships between those
tables.
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