通过PHP更新多个MYSQL行

Question

I am fairly new to PHP, I know the basics but not sure how to update multiple rows at once in PHP? form is similar to this:

<form action="sortorder.php" id="sortorder">

<input style='width:20px;' type='text' name='photo' value='1'>
<input style='width:20px;' type='text' name='sortorder' value='1'>

<input style='width:20px;' type='text' name='photo' value='2'>
<input style='width:20px;' type='text' name='sortorder' value='2'>

<input style='width:20px;' type='text' name='photo' value='3'>       
<input style='width:20px;' type='text' name='sortorder' value='3'>

</form>

I need to apply similar code to the following to each

UPDATE photos SET sortorder = <input> WHERE id = '1';
UPDATE photos SET sortorder = <input> WHERE id = '2';      

I just have no idea how to take multiple bits of dynamic data and update them all. Can someone point me in the right direction? I realise I need to put them into an array, but I just don't know how.

Thank you in advance.

Answer 1

Let's say you have the Ids 1,2,3,4. You could do something like this:

UPDATE photos SET sortorder = <yourvalue> WHERE id IN (1,2,3,4);

Now instead of explicitly writing IN (1,2,3,4) you can dynamically generate the values you want to be updated. That could be through PHP or via SQL:

UPDATE photos SET sortorder = <yourvalue> 
WHERE id IN 
(SELECT id from anotherTable WHERE otherattribute = someotherValue);

You should note that only text must be in ' - numbers must be written without! For your example I assumed that id is a number and not a text - if it is indeed a text (or char/varchar), you need to write ... IN ('1','2','3','4') . But I would advise you to use integer for your ids.

Update: To get the specific values of your inputs, you can do the following:

<input ... name='photo[]' value='1' />
<input ... name='sortorder[]' value='1' />

This way you will get two arrays when you send your form: $_POST[photo] and $_POST[sortorder] .

Now iterate through both of them (sorry if the syntax isn't correct, didn't use PHP for a long time, but the idea should be clear):

for($i = 0; $i < photo.length; $i++){
    // your query here
    // something like:
    UPDATE photos SET sortorder = sortorder[i] WHERE id = photo[i];
    // of course you have to sanitize your input!
}

As I said: I'm not sure if that's exactly how you would write this in PHP, but the idea is to go through the arrays and take those values into your query.

Answer 2

As per your query

UPDATE photos SET sortorder = WHERE id = '1';
UPDATE photos SET sortorder = WHERE id = '2';

id column is varchar and not int and also you have not specified what to store in sortorder.

I am giving solution considering following queries

UPDATE photos SET sortorder = '1' WHERE id = '1';
UPDATE photos SET sortorder = '2' WHERE id = '2';

in that case you should query like :

UPDATE photos SET sortorder = id;

if sortorder is int and id is varchar then query should be

UPDATE photos SET sortorder = CAST(id as unsigned);

and if you want to update for some specific values only then it should be like

UPDATE photos SET sortorder = CAST(id as unsigned) where id in ('1','2','3');

Answer 3

It seams you wanna make the insert sql more effective. But actualy, update one row by id per time will shorten the lock time and helps improving concurrence ability. On the other hand, there is no way to update different rows by different conditions in one sql.