diff options
| author | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:39:39 +0200 |
|---|---|---|
| committer | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:39:39 +0200 |
| commit | f4fb1db458fab52d0493ead52c9ea7e01206eaa7 (patch) | |
| tree | c549600f342f4d3f0df75a2f2f7c265be0f1cc72 /user_guide/database/forge.html | |
| parent | c4dd200c1155a118afa32cd91d9bd67bc243f83a (diff) | |
Moved tutorial to new user guide directory.
Diffstat (limited to 'user_guide/database/forge.html')
| -rw-r--r-- | user_guide/database/forge.html | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/user_guide/database/forge.html b/user_guide/database/forge.html deleted file mode 100644 index 6b8709892..000000000 --- a/user_guide/database/forge.html +++ /dev/null @@ -1,234 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> -<head> - -<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> -<title>Database Forge Class : CodeIgniter User Guide</title> - -<style type='text/css' media='all'>@import url('../userguide.css');</style> -<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> - -<script type="text/javascript" src="../nav/nav.js"></script> -<script type="text/javascript" src="../nav/prototype.lite.js"></script> -<script type="text/javascript" src="../nav/moo.fx.js"></script> -<script type="text/javascript" src="../nav/user_guide_menu.js"></script> - -<meta http-equiv='expires' content='-1' /> -<meta http-equiv= 'pragma' content='no-cache' /> -<meta name='robots' content='all' /> -<meta name='author' content='ExpressionEngine Dev Team' /> -<meta name='description' content='CodeIgniter User Guide' /> - -</head> -<body> - -<!-- START NAVIGATION --> -<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> -<div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> -<div id="masthead"> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td><h1>CodeIgniter User Guide Version 2.0.3</h1></td> -<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> -</tr> -</table> -</div> -<!-- END NAVIGATION --> - - -<!-- START BREADCRUMB --> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td id="breadcrumb"> -<a href="http://codeigniter.com/">CodeIgniter Home</a> › -<a href="../index.html">User Guide Home</a> › -<a href="index.html">Database Library</a> › -Database Forge Class -</td> -<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> -</tr> -</table> -<!-- END BREADCRUMB --> - - -<br clear="all" /> - - -<!-- START CONTENT --> -<div id="content"> - -<h1>Database Forge Class</h1> - -<p>The Database Forge Class contains functions that help you manage your database.</p> - -<h3>Table of Contents</h3> - -<ul> -<li><a href="#init">Initializing the Forge Class</a></li> -<li><a href="#create">Creating a Database</a></li> -<li><a href="#drop">Dropping a Database</a></li> -<li><a href="#add_field">Adding Fields</a></li> -<li><a href="#add_key">Adding Keys</a></li> -<li><a href="#create_table">Creating a Table</a></li> -<li><a href="#drop_table">Dropping a Table</a></li> -<li><a href="#rename_table">Renaming a Table</a></li> -<li><a href="#modifying_tables">Modifying a Table</a></li> -</ul> - - -<h2><a name="init"></a>Initializing the Forge Class</h2> - -<p class="important"><strong>Important:</strong> In order to initialize the Forge class, your database driver must -already be running, since the forge class relies on it.</p> - -<p>Load the Forge Class as follows:</p> - -<code>$this->load->dbforge()</code> - -<p>Once initialized you will access the functions using the <dfn>$this->dbforge</dfn> object:</p> - -<code>$this->dbforge->some_function()</code> -<h2><a name="create"></a>$this->dbforge->create_database('db_name')</h2> - -<p>Permits you to create the database specified in the first parameter. Returns TRUE/FALSE based on success or failure:</p> - -<code>if ($this->dbforge->create_database('my_db'))<br /> -{<br /> - echo 'Database created!';<br /> -}</code> - - - - -<h2><a name="drop"></a>$this->dbforge->drop_database('db_name')</h2> - -<p>Permits you to drop the database specified in the first parameter. Returns TRUE/FALSE based on success or failure:</p> - -<code>if ($this->dbforge->drop_database('my_db'))<br /> -{<br /> - echo 'Database deleted!';<br /> -}</code> - - -<h1>Creating and Dropping Tables</h1> -<p>There are several things you may wish to do when creating tables. Add fields, add keys to the table, alter columns. CodeIgniter provides a mechanism for this.</p> -<h2><a name="add_field" id="add_field"></a>Adding fields</h2> -<p>Fields are created via an associative array. Within the array you must include a 'type' key that relates to the datatype of the field. For example, INT, VARCHAR, TEXT, etc. Many datatypes (for example VARCHAR) also require a 'constraint' key.</p> -<p><code>$fields = array(<br /> - 'users' => array(<br /> - 'type' => 'VARCHAR',<br /> - 'constraint' => '100',<br /> - ),<br /> - );<br /> - <br /> -// will translate to "users VARCHAR(100)" when the field is added.</code></p> -<p>Additionally, the following key/values can be used:</p> -<ul> - <li>unsigned/true : to generate "UNSIGNED" in the field definition.</li> - <li>default/value : to generate a default value in the field definition.</li> - <li>null/true : to generate "NULL" in the field definition. Without this, the field will default to "NOT NULL".</li> - <li>auto_increment/true : generates an auto_increment flag on the field. Note that the field type must be a type that supports this, such as integer.</li> - </ul> -<p><code>$fields = array(<br /> - 'blog_id' => array(<br /> - 'type' => 'INT',<br /> - 'constraint' => 5, <br /> - 'unsigned' => TRUE,<br /> - 'auto_increment' => TRUE<br /> - ),<br /> - 'blog_title' => array(<br /> - 'type' => 'VARCHAR',<br /> - 'constraint' => '100',<br /> - ),<br /> - 'blog_author' => array(<br /> - 'type' =>'VARCHAR',<br /> - 'constraint' => '100',<br /> - 'default' => 'King of Town',<br /> - ),<br /> - 'blog_description' => array(<br /> - 'type' => 'TEXT',<br /> - 'null' => TRUE,<br /> - ),<br /> - );<br /> -</code></p> -<p>After the fields have been defined, they can be added using <dfn>$this->dbforge->add_field($fields);</dfn> followed by a call to the <dfn>create_table()</dfn> function.</p> -<h3>$this->dbforge->add_field()</h3> -<p>The add fields function will accept the above array.</p> -<h3>Passing strings as fields</h3> -<p>If you know exactly how you want a field to be created, you can pass the string into the field definitions with add_field()</p> -<p><code>$this->dbforge->add_field("label varchar(100) NOT NULL DEFAULT 'default label'");</code></p> -<p class="important">Note: Multiple calls to <dfn>add_field()</dfn> are cumulative.</p> -<h3>Creating an id field</h3> -<p>There is a special exception for creating id fields. A field with type id will automatically be assinged as an INT(9) auto_incrementing Primary Key.</p> -<p><code>$this->dbforge->add_field('id');<br /> - // gives id INT(9) NOT NULL AUTO_INCREMENT</code></p> -<h2><a name="add_key" id="add_key"></a>Adding Keys</h2> -<p>Generally speaking, you'll want your table to have Keys. This is accomplished with <dfn>$this->dbforge->add_key('field')</dfn>. An optional second parameter set to TRUE will make it a primary key. Note that <dfn>add_key()</dfn> must be followed by a call to <dfn>create_table()</dfn>.</p> -<p>Multiple column non-primary keys must be sent as an array. Sample output below is for MySQL.</p> -<p><code>$this->dbforge->add_key('blog_id', TRUE);<br /> - // gives PRIMARY KEY `blog_id` (`blog_id`)<br /> - <br /> - $this->dbforge->add_key('blog_id', TRUE);<br /> - $this->dbforge->add_key('site_id', TRUE);<br /> - // gives PRIMARY KEY `blog_id_site_id` (`blog_id`, `site_id`)<br /> - <br /> - $this->dbforge->add_key('blog_name');<br /> - // gives KEY `blog_name` (`blog_name`)<br /> - <br /> - $this->dbforge->add_key(array('blog_name', 'blog_label'));<br /> - // gives KEY `blog_name_blog_label` (`blog_name`, `blog_label`)</code></p> -<h2><a name="create_table" id="create_table"></a>Creating a table</h2> -<p>After fields and keys have been declared, you can create a new table with</p> -<p><code>$this->dbforge->create_table('table_name');<br /> -// gives CREATE TABLE table_name</code></p> -<p>An optional second parameter set to TRUE adds an "IF NOT EXISTS" clause into the definition</p> -<p><code>$this->dbforge->create_table('table_name', TRUE);<br /> -// gives CREATE TABLE IF NOT EXISTS table_name</code></p> -<h2><a name="drop_table" id="drop_table"></a>Dropping a table</h2> -<p>Executes a DROP TABLE sql</p> -<p><code>$this->dbforge->drop_table('table_name');<br /> - // gives DROP TABLE IF EXISTS table_name</code></p> -<h2><a name="rename_table" id="rename_table"></a>Renaming a table</h2> -<p>Executes a TABLE rename</p> -<p><code>$this->dbforge->rename_table('old_table_name', 'new_table_name');<br /> - // gives ALTER TABLE old_table_name RENAME TO new_table_name</code></p> -<h1><a name="modifying_tables" id="modifying_tables"></a>Modifying Tables</h1> -<h2>$this->dbforge->add_column()</h2> -<p>The add_column() function is used to modify an existing table. It accepts the same field array as above, and can be used for an unlimited number of additional fields.</p> -<p><code>$fields = array(<br /> - 'preferences' => array('type' => 'TEXT')<br /> -);<br /> -$this->dbforge->add_column('table_name', $fields);<br /> -<br /> -// gives ALTER TABLE table_name ADD preferences TEXT</code></p> -<h2>$this->dbforge->drop_column()</h2> -<p>Used to remove a column from a table. </p> -<p><code>$this->dbforge->drop_column('table_name', 'column_to_drop');</code></p> -<h2>$this->dbforge->modify_column()</h2> -<p>The usage of this function is identical to add_column(), except it alters an existing column rather than adding a new one. In order to change the name you can add a "name" key into the field defining array.</p> -<p><code>$fields = array(<br /> - 'old_name' => array(<br /> - 'name' => 'new_name',<br /> - 'type' => 'TEXT',<br /> - ),<br /> -);<br /> -$this->dbforge->modify_column('table_name', $fields);<br /> - <br /> - // gives ALTER TABLE table_name CHANGE old_name new_name TEXT </code></p> -<p> </p> -</div> -<!-- END CONTENT --> - - -<div id="footer"> -<p> -Previous Topic: <a href="caching.html">DB Caching Class</a> - · -<a href="#top">Top of Page</a> · -<a href="../index.html">User Guide Home</a> · -Next Topic: <a href="utilities.html">Database Utilities Class</a><a href="../libraries/email.html"></a></p> -<p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006 - 2011 · <a href="http://ellislab.com/">EllisLab, Inc.</a></p> -</div> - -</body> -</html>
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