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=== Overview ===
<code>SELECT</code> is the most common operation in SQL, called "the query". <code>SELECT</code> retrieves data from one or more [[Table (database)|table]]s, or expressions. Standard <code>SELECT</code> statements have no persistent effects on the database. Some non-standard implementations of <code>SELECT</code> can have persistent effects, such as the <code>SELECT INTO</code> syntax provided in some databases.<ref name="ms-sql-select-into">{{ cite book | chapter = Transact-SQL Reference | title = SQL Server Language Reference | series = SQL Server 2005 Books Online | publisher = Microsoft | date = 2007-09-15 | url = http://msdn.microsoft.com/en-us/library/ms188029.aspx | accessdate = 2007-06-17 }}</ref>
Queries allow the user to describe desired data, leaving the [[Database management system|database management system (DBMS)]] to carry out [[query plan|planning]], [[query optimizer|optimizing]], and performing the physical operations necessary to produce that result as it chooses.
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