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wpdb::get_col( string|null $query = null, int $x ): array

Retrieves one column from the database.

Description

Executes a SQL query and returns the column from the SQL result.
If the SQL result contains more than one column, the column specified is returned.
If $query is null, the specified column from the previous SQL result is returned.

Parameters

$query string|null Optional
SQL query. Defaults to previous query.

Default: null

$x int Optional
Column to return. Indexed from 0.

Return

array Database query result. Array indexed from 0 by SQL result row number.

Source

File: wp-includes/class-wpdb.php. View all references

public function get_col( $query = null, $x = 0 ) {
	if ( $query ) {
		if ( $this->check_current_query && $this->check_safe_collation( $query ) ) {
			$this->check_current_query = false;
		}

		$this->query( $query );
	}

	$new_array = array();
	// Extract the column values.
	if ( $this->last_result ) {
		for ( $i = 0, $j = count( $this->last_result ); $i < $j; $i++ ) {
			$new_array[ $i ] = $this->get_var( null, $x, $i );
		}
	}
	return $new_array;
}

Uses

Uses Description
wpdb::check_safe_collation() wp-includes/class-wpdb.php

Checks if the query is accessing a collation considered safe on the current version of MySQL.
wpdb::query() wp-includes/class-wpdb.php

Performs a database query, using current database connection.
wpdb::get_var() wp-includes/class-wpdb.php

Retrieves one variable from the database.

Used By

Used By Description
_wp_batch_update_comment_type() wp-includes/comment.php

Updates the comment type for a batch of comments.
wp_delete_site() wp-includes/ms-site.php

Deletes a site from the database.
WP_Network_Query::get_network_ids() wp-includes/class-wp-network-query.php

Used internally to get a list of network IDs matching the query vars.
WP_Site_Query::get_site_ids() wp-includes/class-wp-site-query.php

Used internally to get a list of site IDs matching the query vars.
wp_get_users_with_no_role() wp-includes/user.php

Gets the user IDs of all users with no role on this site.
WP_Comment_Query::get_comment_ids() wp-includes/class-wp-comment-query.php

Used internally to get a list of comment IDs matching the query vars.
maybe_drop_column() wp-admin/install-helper.php

Drops column from database table, if it exists.
export_wp() wp-admin/includes/export.php

Generates the WXR export file for download.
WP_User_Search::query() wp-admin/includes/deprecated.php

Executes the user search query.
get_author_user_ids() wp-admin/includes/deprecated.php

Get all user IDs.
get_editable_user_ids() wp-admin/includes/deprecated.php

Gets the IDs of any users who can edit posts.
get_nonauthor_user_ids() wp-admin/includes/deprecated.php

Gets all users who are not authors.
wpmu_delete_user() wp-admin/includes/ms.php

Delete a user from the network and remove from all sites.
populate_options() wp-admin/includes/schema.php

Create WordPress options and set the default values.
maybe_create_table() wp-admin/includes/upgrade.php

Creates a table in the database, if it doesn’t already exist.
maybe_add_column() wp-admin/includes/upgrade.php

Adds column to a database table, if it doesn’t already exist.
wp_delete_user() wp-admin/includes/user.php

Remove user and optionally reassign posts and links to another user.
meta_form() wp-admin/includes/template.php

Prints the form in the Custom Fields meta box.
WP_MS_Sites_List_Table::prepare_items() wp-admin/includes/class-wp-ms-sites-list-table.php

Prepares the list of sites for display.
get_meta_keys() wp-admin/includes/post.php

Returns a list of previously defined keys.
get_available_post_mime_types() wp-includes/post.php

Gets all available post MIME types for a given post type.
_wp_delete_orphaned_draft_menu_items() wp-admin/includes/nav-menu.php

Deletes orphaned draft menu items
get_usermeta() wp-includes/deprecated.php

Retrieve user metadata.
WP_Query::get_posts() wp-includes/class-wp-query.php

Retrieves an array of posts based on query variables.
do_enclose() wp-includes/functions.php

Checks content for video and audio links to add as enclosures.
wp_set_object_terms() wp-includes/taxonomy.php

Creates term and taxonomy relationships.
wp_delete_term() wp-includes/taxonomy.php

Removes a term from the database.
get_objects_in_term() wp-includes/taxonomy.php

Retrieves object IDs of valid taxonomy and term.
WP_User_Query::query() wp-includes/class-wp-user-query.php

Executes the query, with the current variables.
count_users() wp-includes/user.php

Counts number of users who have each of the user roles.
wp_delete_auto_drafts() wp-includes/post.php

Deletes auto-drafts for new posts that are > 7 days old.
wp_delete_attachment() wp-includes/post.php

Trashes or deletes an attachment.
get_all_page_ids() wp-includes/post.php

Gets a list of page IDs.
wp_delete_post() wp-includes/post.php

Trashes or deletes a post or page.
remove_user_from_blog() wp-includes/ms-functions.php

Removes a user from a blog.
is_multi_author() wp-includes/author-template.php

Determines whether this site has more than one author.
wp_delete_comment() wp-includes/comment.php

Trashes or deletes a comment.
delete_metadata() wp-includes/meta.php

Deletes metadata for the specified object.
update_metadata() wp-includes/meta.php

Updates metadata for the specified object. If no value already exists for the specified object ID and metadata key, the metadata will be added.

Changelog

Version Description
0.71 Introduced.

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Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/classes/wpdb/get_col