php - 如果列不为 NULL，如何更新表中的列？

Question

我有一个将数据提交到表格的表单。除了 received_date 和 gid 之外，其他用户可以编辑表格列。如何在 PHP 更新脚本期间跳过该列？

这是 default_table(简化):

gid     received_date     detail     max_number   status
1                NULL       NULL          NULL         1

第一次输入后:

gid     received_date         detail     max_number   status
1          2017-07-17       Swimsuit            100        1

经过秒等输入:

gid     received_date          detail     max_number   status
1          2017-07-17     Swimsuit XL            250        1

可能是这样的:

UPDATE t_goods 
IF(t_goods.received_date = NULL){
   SET received_dates = received_date(today_date), detail = detail, max_number = add_stock WHERE gid = gid
}
ELSE{
   SET detail = detail, max_number = add_stock WHERE gid = gid
}

注意:查询只是一个伪代码。

Answer 1

像那样尝试。

UPDATE t_goods 
SET 
detail = detail, 
max_number = add_stock,
received_date = IF(received_date IS NULL, received_dates,received_date)
WHERE  gid = gid;

IF(received_date IS NULL, received_dates,received_date) 如果 received_date 为 null，此等式更新新的 received_dates 值，否则它将 received_date 保持为旧值。