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

Retrieve one column from the database.

Description Description

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

Parameters Parameters


(string|null) (Optional) SQL query. Defaults to previous query.

Default value: null


(int) (Optional) Column to return. Indexed from 0.

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Return Return

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

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Source Source

File: wp-includes/wp-db.php

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

		if ( $query ) {
			$this->query( $query );

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

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Changelog Changelog

Version Description
0.71 Introduced.

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User Contributed Notes User Contributed Notes

  1. Skip to note content
    Contributed by Big-Erny
    global $wpdb;
    $table_name = $wpdb->prefix . 'some_custom_table_name';
    $field_name = 'some_field';
    $user_id = get_current_user_id();
    $prepared_statement = $wpdb->prepare( "SELECT {$field_name} FROM {$table_name} WHERE  user_id = %d", $user_id );
    $values = $wpdb->get_col( $prepared_statement );

    Returns an array of $field_name values in the $table_name that match the $user_id

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