$wpdb->prepare was called incorrectly when inserting multiple records

Question

This works:

$values = array();

foreach (  $_POST as $key => $value ) {
    $values[] = $wpdb->prepare( "(%d,%s,%s)", $post_id, $key, $value );
}

$query = "INSERT INTO {$table} (post_id, meta_key, meta_value) VALUES ";
$query .= implode( ",\n", $values );
$wpdb->query( $wpdb->prepare( "$query", $values ) );

But it throws this notice:

PHP Notice: wpdb::prepare was called incorrectly. The query does not contain the correct number of placeholders (0) for the number of arguments passed (3).

How can I avoid the Notice?

Answer 1

Well, you don't need the second $wpdb->prepare() and just do $wpdb->query( $query );. The reason is because the $query does not contain any placeholders just as stated in the notice; only the items in $values contain the placeholders, but you already prepared them in the foreach. Additionally, be sure to run the query() only if the array $values is not empty.