sql update statement doesn't work

Question

I have to increment a field in my DB each time I execute this statement:

$sql="UPDATE `product` SET buyCount = buyCount+1 WHERE id=".$productID;

But it doesn't work. Any help ?

Answer 1

My best guess would be that BuyCount is initialized to NULL and not 0. Try:

set BuyCount = coalesce(BuyCount, 0) + 1

Alternatively, your where clause is failing. You might try setting a value in another column to see if it is working.

Answer 2

将结束 " 移动到查询的末尾并将变量括在单引号中。

$sql="UPDATE product SET buyCount = buyCount+1 WHERE id='$productID'";

Answer 3

试试这个

$sql="UPDATE product SET buyCount = buyCount+1 WHERE id= $productID";