You can add SQL functions, WHERE, and JOIN statements to a view and present the data as if the data were coming from one single table.If you have the Northwind database you can see that it has several views installed by default.
Performance Tuning When You CAN Fix the Queries – Your users are frustrated because the app is too slow, and you can change the SQL queries – but how?
However, it is common to see them misued, or neglected.
Joe Celko tackles an introduction to the subject, but there is something about the topic that makes it likely that even the experienced developer will find out something new from reading it.
The most common offender is the “Volkswagen” coder who prefixes or suffixes the _” in violation of ISO-11179 rules. This is as silly as prefixing every noun in a novel with “n_” so the reader will know that the word is a noun in English grammar.
The ANSI Standard SQL syntax for the statement instead of a list of column declarations throws their mindset in the wrong direction.