Alias (SQL): Difference between revisions

Revision as of 14:44, 31 January 2015

Revision as of 10:53, 7 January 2016

Line 1:

{{refimprove|date=October 2013}}

An '''alias''' is a feature of SQL that is supported by most, if not all, [[RDBMS|relational database management systems (RDBMSs)]]. Aliases provide [[database administrator]]s, as well as other database users, with the ability to reduce the amount of code required for a query, and to make queries generally simpler to understand. In addition, aliasing can be used as an [[Obfuscation (software)|obfuscation technique]] to protect the real names of database fields.

In SQL, you can alias both tables themselves,and which[[Column (database)|columns]]. A table alias is also called a Correlation'''correlation Name,name'''<ref>ANSI Standard SQL - Foundation Document - Date: 2010-10-14</ref> or [[Column (database)|columns]]. A programmer can use an alias temporarily assign another name to a table or column (for the duration of the a[[Select (SQL)|SELECT query]]). by usingAssigning an alias. In other words, it does not actually rename the column or table. This is often useful when either tables or their columns have very long or complex names. An alias name could be anything, but usually it is kept short. For example, it might be common to use a table alias such as "pi" for a table named "price_information".

The general syntax of an alias is <code>SELECT * FROM table_name [AS] alias_name</code>. Note that the AS keyword is completely optional and is usually kept for readability purposes. Here is some sample data that the queries below will be referencing: