Differences

This shows you the differences between the selected revision and the current version of the page.

punbb13:database_helpers 2010/04/12 06:45 punbb13:database_helpers 2020/02/06 11:04 current
Line 23: Line 23:
Let's discuss how to use the query builder. Let's discuss how to use the query builder.
-===== Data Manipulation in query builder ====== +===== Query Builder: Data Manipulation ======
- +
-First consider the DML (Data Manipulation Language) part of the PunBB database layer class.+
==== SELECT ==== ==== SELECT ====
Line 136: Line 134:
$forum_db->query_build($query) or error(__FILE__, __LINE__);</code> $forum_db->query_build($query) or error(__FILE__, __LINE__);</code>
-===== Data Definition in query builder ======+===== Data Definition ======
Now let's consider the DDL (Data Definition Language) part of the PunBB database layer class. Now let's consider the DDL (Data Definition Language) part of the PunBB database layer class.
Line 216: Line 214:
<code php>function drop_field($table_name, $field_name, $no_prefix = false)</code> <code php>function drop_field($table_name, $field_name, $no_prefix = false)</code>
-Deletes the ''$field_name'' field from the ''$table_name'' table.+Removes the ''$field_name'' field from the ''$table_name'' table.
-Here are some examples of the fields manipulation.+Here are examples of the fields manipulation.
-<code php>// Taken from db_update.php+<code php>// Taken from admin/db_update.php
$forum_db->alter_field('posts', 'poster_ip', 'VARCHAR(39)', true); $forum_db->alter_field('posts', 'poster_ip', 'VARCHAR(39)', true);
$forum_db->alter_field('users', 'registration_ip', 'VARCHAR(39)', false, '0.0.0.0');</code> $forum_db->alter_field('users', 'registration_ip', 'VARCHAR(39)', false, '0.0.0.0');</code>
Line 233: Line 231:
==== Indexes ==== ==== Indexes ====
-FIXME 
 +<code php>function index_exists($table_name, $index_name, $no_prefix = false)</code>
 +
 +Checks if the index ''$index_name'' is present in the table ''$table_name''.
 +
 +<code php>function add_index($table_name, $index_name, $index_fields, $unique = false, $no_prefix = false)</code>
 +
 +Adds an index to the ''$table_name'' table. ''$index_fields'' is the array of fields to be added to the index.
 +
 +<code php>function drop_index($table_name, $index_name, $no_prefix = false)</code>
 +
 +Removes the ''$index_name'' index from the ''$table_name'' table.
 +
 +Here are examples of the indexes manipulation.
 +
 +<code php>// Taken from admin/db_update.php
 +if (!$forum_db->index_exists('online', 'user_id_ident_idx'))
 +{
 +  ...
 +  $forum_db->add_index('online', 'user_id_ident_idx', array('user_id', 'ident'), true);
 +  ...
 +}
 +
 +$forum_db->drop_index('online', 'user_id_idx');</code>

Personal Tools