php - how to get next batch number corresponding to product code with php mysql

Question

Please help me to find next batch number corresponding to product code with using PHP and MySQL. My table is like below given image:

Table Screenshot

If I want to enter new batch of product RM-SO-070G then the PHP form must get new batch number accordingly.

Answer 1

创建一个额外的表，它将作为一个序列器 - 该表将只有一个列保存下一个批次值。每次将新产品添加到初始表时，您都会从排序器表中获取批号，并使用您希望添加的下一个产品的下一个批号更新排序器。

Answer 2

您的 SQL 应该看起来像这样......

SELECT `some_tbl`.`batch_no` FROM `some_tbl` WHERE `some_tbl`.`product_code` = ? ORDER BY `some_tbl`.`batch_no` DESC LIMIT 1

然后一旦你得到这些结果，你需要bt从前面删除batch_no

$next_batch_no = intval(substr($result_row['batch_no'], 2))++;

Answer 3

尝试这个：

$product = "RM-SO-070G";
$previous = "bt001";
$query = "SELECT batch_no FROM table WHERE product_code = '".$product."' 
              AND batch_no = (SELECT MIN(batch_no) FROM table 
                  WHERE batch_no > '".$previous."');";
$result = mysql_query($query);
...