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<h1 align="center">SQL As Understood By SQLite</h1><p><a href="lang.html">[Top]</a></p><h2>CREATE VIRTUAL TABLE</h2><h4><a href="syntaxdiagrams.html#create-virtual-table-stmt">create-virtual-table-stmt:</a></h4><blockquote> <img alt="syntax diagram create-virtual-table-stmt" src="images/syntax/create-virtual-table-stmt.gif"></img> </blockquote>
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<p>A <a href="vtab.html">virtual table</a> is an interface to an external storage or computation
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engine that appears to be a table but does not actually store information
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in the database file.</p>
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<p>In general, you can do anything with a <a href="vtab.html">virtual table</a> that can be done
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with an ordinary table, except that you cannot create indices or triggers on a
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virtual table. Some virtual table implementations might impose additional
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restrictions. For example, many virtual tables are read-only.</p>
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<p>The <module-name> is the name of an object that implements
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the virtual table. The <module-name> must be registered with
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the SQLite database connection using
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<a href="c3ref/create_module.html">sqlite3_create_module()</a> or <a href="c3ref/create_module.html">sqlite3_create_module_v2()</a>
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prior to issuing the CREATE VIRTUAL TABLE statement.
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The module takes zero or more comma-separated arguments.
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The arguments can be just about any text as long as it has balanced
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parentheses. The argument syntax is sufficiently general that the
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arguments can be made to appear as <a href="lang_createtable.html#tablecoldef">column definitions</a> in a traditional
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<a href="lang_createtable.html">CREATE TABLE</a> statement.
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SQLite passes the module arguments directly
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to the <a href="vtab.html#xcreate">xCreate</a> and <a href="vtab.html#xconnect">xConnect</a> methods of the module implementation
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without any interpretation. It is the responsibility
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of the module implementation to parse and interpret its own arguments.</p>
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<p>A virtual table is destroyed using the ordinary
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<a href="lang_droptable.html">DROP TABLE</a> statement. There is no
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DROP VIRTUAL TABLE statement.</p>