At the record level, delete is the opposite of insert. It is used to
delete records in a table.
The other thing you'll want to do to a record -- change some of the
information in it! Update is used to update, or rewrite, a record.
The select instruction picks a record, or records, from a table or tables.
Select is the command that provides the real "query" in SQL. the select
command enables you to, for example, select all addresses where the city is
Atlanta and the TV Brand Installed is Sony. In this manner you are
querying the database for all records that match some specific criteria.
You will spend lots of time writing select queries. Options in select
commands allow you to create a special view of the information in a database and
sequence the record however you wish.
These few simple commands provide the basis of all the power that a database
management system can bring to your application. It seems too simple to be
true, but it is that very simplicity which makes the Structured Query Language
such a valuable tool. There are other commands available, especially in
some DBMS implementations, but these basic commands are always available.
Remembering these few command will help you very much as you progress with your
DBMS coding education.