Question

term_exists( int|string $term,  string $taxonomy = '',  int $parent = null )

Check if Term exists.

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description

Formerly is_term(), introduced in 2.3.0.

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参数

$term

(int|string) (Required) The term to check. Accepts term ID, slug, or name.

$taxonomy

(string) (Optional) The taxonomy name to use

Default value: ''

$parent

(int) (Optional) ID of parent term under which to confine the exists search.

Default value: null

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返回值

(mixed) Returns null if the term does not exist. Returns the term ID if no taxonomy is specified and the term ID exists. Returns an array of the term ID and the term taxonomy ID the taxonomy is specified and the pairing exists.

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源代码

File: wp-includes/taxonomy.php

function term_exists( $term, $taxonomy = '', $parent = null ) {
	global $wpdb;

	$select = "SELECT term_id FROM $wpdb->terms as t WHERE ";
	$tax_select = "SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE ";

	if ( is_int($term) ) {
		if ( 0 == $term )
			return 0;
		$where = 't.term_id = %d';
		if ( !empty($taxonomy) )
			return $wpdb->get_row( $wpdb->prepare( $tax_select . $where . " AND tt.taxonomy = %s", $term, $taxonomy ), ARRAY_A );
		else
			return $wpdb->get_var( $wpdb->prepare( $select . $where, $term ) );
	}

	$term = trim( wp_unslash( $term ) );
	$slug = sanitize_title( $term );

	$where = 't.slug = %s';
	$else_where = 't.name = %s';
	$where_fields = array($slug);
	$else_where_fields = array($term);
	$orderby = 'ORDER BY t.term_id ASC';
	$limit = 'LIMIT 1';
	if ( !empty($taxonomy) ) {
		if ( is_numeric( $parent ) ) {
			$parent = (int) $parent;
			$where_fields[] = $parent;
			$else_where_fields[] = $parent;
			$where .= ' AND tt.parent = %d';
			$else_where .= ' AND tt.parent = %d';
		}

		$where_fields[] = $taxonomy;
		$else_where_fields[] = $taxonomy;

		if ( $result = $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $where AND tt.taxonomy = %s $orderby $limit", $where_fields), ARRAY_A) )
			return $result;

		return $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $else_where AND tt.taxonomy = %s $orderby $limit", $else_where_fields), ARRAY_A);
	}

	if ( $result = $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $where $orderby $limit", $where_fields) ) )
		return $result;

	return $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $else_where $orderby $limit", $else_where_fields) );
}

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更新日志

Version	description
3.0.0	Introduced.

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相关函数

Uses

• wp-includes/formatting.php: wp_unslash()
• wp-includes/formatting.php: sanitize_title()
• wp-includes/wp-db.php: wpdb::get_row()
• wp-includes/wp-db.php: wpdb::get_var()
• wp-includes/wp-db.php: wpdb::prepare()

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Used By

• wp-admin/includes/class-wp-press-this.php: WP_Press_This::add_category()
• wp-admin/includes/export.php: export_wp()
• wp-admin/includes/taxonomy.php: category_exists()
• wp-admin/includes/taxonomy.php: wp_insert_category()
• wp-admin/includes/taxonomy.php: tag_exists()
• wp-admin/includes/taxonomy.php: wp_create_term()
• wp-includes/deprecated.php: is_term()
• wp-includes/taxonomy.php: wp_unique_term_slug()
• wp-includes/taxonomy.php: wp_update_term()
• wp-includes/taxonomy.php: wp_insert_term()
• wp-includes/taxonomy.php: wp_set_object_terms()
• wp-includes/taxonomy.php: wp_remove_object_terms()
• wp-includes/taxonomy.php: wp_delete_term()
Show 8 more used by Hide more used by

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User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 1You must log in to vote on the helpfulness of this note Contributed by Maje Media LLC

   The returned array of

   ['term_id' => ID, 'term_taxonomy_id' => ID]

   returns a string for the ID instead of ints. If you need int values you’ll need to convert them to ints.

Checks to see if ‘Uncategorized’ category exists
Check if the ‘Uncategorized’ category exists
Note: term_exists() runs a database query. get_term() can be used for the same purpose, except it uses the term cache.

$term = term_exists( 'Uncategorized', 'category' );
if ( $term !== 0 && $term !== null ) {
	echo __( "'Uncategorized' category exists!", "textdomain" );
}

Checks to see if ‘Untagged’ post_tag category exists
Note: term_exists() runs a database query. get_term() can be used for the same purpose, except it uses the term cache.

$term = term_exists( 'Untagged', 'post_tag' );
if ( $term !== 0 && $term !== null ) {
	echo __( "'Untagged' post_tag exists!", "textdomain" );
}