批量插入原理以及案例

public function insertALl() {

    $length = 100;
        
    $sql = "select count(*) SALE,PRODUCT_ID from order_product group by PRODUCT_ID";

    $data = Db::query($sql);

    $data_length = count($data);

    $step_length = ceil($data_length / $length);

    for ($i=0; $i < $step_length ; $i++) {

        $sql_insert = "insert into order_product_sales(SALES, PRODUCT_ID) values";
        
        $start_index = $i * $length;
        $end_index =  ($i+1) * $length;

        if($end_index > $data_length) $end_index = $data_length;

        for ($j = $start_index; $j < $end_index ; $j++) {
            $sql_insert = $sql_insert. "(".$data[$j]['SALE'] . ',' . $data[$j]['PRODUCT_ID'] . '),';
        }

        $sql_insert = substr($sql_insert, 0, -1);

        Db::execute($sql_insert);
    }
}

先设置步长