I don't quite understand why queries are important in databases. Could
someone explain?
Thanks.
That's a bit like asking why expressions are important in
spreadsheets, or why saws are important in carpentry. Queries are THE
basis for any productive use of databases!
Tables store raw data, usually in a normalized structure of multiple
related tables.
If you want to:
- select a subset of the fields in a Table
- select a subset of the rows in a Table
- Combine data from two or more tables
- sort data
- modify data (more than one record at a time)
- create new data from old
- create new tables
- export data to an external file
then the first tool to consider is a Query. There are (usually) other
ways to do any of these but all of these can be done with a Query, and
generally a Query is in fact the appropriate tool.
John W. Vinson[MVP]
