📄 lang_attach.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"><html><head><title>SQLite Query Language: ATTACH DATABASE</title><style type="text/css">body { margin: auto; font-family: "Verdana" "sans-serif"; padding: 8px 1%;}a { color: #45735f }a:visited { color: #734559 }.logo { position:absolute; margin:3px; }.tagline { float:right; text-align:right; font-style:italic; width:240px; margin:12px; margin-top:58px;}.toolbar { font-variant: small-caps; text-align: center; line-height: 1.6em; margin: 0; padding:1px 8px;}.toolbar a { color: white; text-decoration: none; padding: 6px 12px; }.toolbar a:visited { color: white; }.toolbar a:hover { color: #80a796; background: white; }.content { margin: 5%; }.content dt { font-weight:bold; }.content dd { margin-bottom: 25px; margin-left:20%; }.content ul { padding:0px; padding-left: 15px; margin:0px; }/* rounded corners */.se { background: url(images/se.png) 100% 100% no-repeat #80a796}.sw { background: url(images/sw.png) 0% 100% no-repeat }.ne { background: url(images/ne.png) 100% 0% no-repeat }.nw { background: url(images/nw.png) 0% 0% no-repeat }</style><meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head><body><div><!-- container div to satisfy validator --><a href="index.html"><img class="logo" src="images/SQLite.gif" alt="SQLite Logo" border="0"></a><div><!-- IE hack to prevent disappearing logo--></div><div class="tagline">Small. Fast. Reliable.<br>Choose any three.</div><table width=100% style="clear:both"><tr><td> <div class="se"><div class="sw"><div class="ne"><div class="nw"> <div class="toolbar"> <a href="about.html">About</a> <a href="sitemap.html">Sitemap</a> <a href="docs.html">Documentation</a> <a href="download.html">Download</a> <a href="copyright.html">License</a> <a href="news.html">News</a> <a href="http://www.sqlite.org/cvstrac/index">Developers</a> <a href="support.html">Support</a> </div></div></div></div></div></td></tr></table> <a href="lang.html"><h2>SQL As Understood By SQLite</h2></a><h3>ATTACH DATABASE</h3><table cellpadding="10"><tr><td align="right" valign="top"><i><font color="#ff3434">sql-statement</font></i> ::=</td><td><b><font color="#2c2cf0">ATTACH </font></b>[<b><font color="#2c2cf0">DATABASE</font></b>]<b><font color="#2c2cf0"> </font></b><i><font color="#ff3434">database-filename</font></i><b><font color="#2c2cf0"> AS </font></b><i><font color="#ff3434">database-name</font></i><b><font color="#2c2cf0"></font></b></td></tr></table><p>The ATTACH DATABASE statement adds another database file to the current database connection. If the filename contains punctuation characters it must be quoted. The names 'main' and 'temp' refer to the main database and the database used for temporary tables. These cannot be detached. Attached databases are removed using the <a href="lang_detach.html">DETACH DATABASE</a> statement.</p><p>You can read from and write to an attached database and youcan modify the schema of the attached database. This is a newfeature of SQLite version 3.0. In SQLite 2.8, schema changesto attached databases were not allowed.</p><p>You cannot create a new table with the same name as a table in an attached database, but you can attach a database which containstables whose names are duplicates of tables in the main database. It is also permissible to attach the same database file multiple times.</p><p>Tables in an attached database can be referred to using the syntax <i>database-name.table-name</i>. If an attached table doesn't have a duplicate table name in the main database, it doesn't require a database name prefix. When a database is attached, all of its tables which don't have duplicate names become the default tableof that name. Any tables of that name attached afterwards require the table prefix. If the default table of a given name is detached, then the last table of that name attached becomes the new default.</p><p>Transactions involving multiple attached databases are atomic,assuming that the main database is not ":memory:". If the maindatabase is ":memory:" then transactions continue to be atomic within each individualdatabase file. But if the host computer crashes in the middleof a COMMIT where two or more database files are updated,some of those files might get the changes where othersmight not.Atomic commit of attached databases is a new feature of SQLite version 3.0.In SQLite version 2.8, all commits to attached databases behaved as ifthe main database were ":memory:".</p><p>There is a compile-time limit of 10 attached database files.</p><hr><small><i>This page last modified 2008/04/15 19:31:05 UTC</i></small></div></body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -