How to update specific records in database using PHP? - php

Question

I have one drop down and lists are aMan, bMan, cMan.I am selecting any one of them from drop down. So whatever I am selecting from drop down I want to update that records according to list. Below update query is updating all my records because i added '$action_points' for each.
For example. If I selected bMan from the drop down then in update table will update only bMan records according to user_id.If I select aMan then update table it will update only aMan with 10.It will not effect on other.
I am getting the issue on update query.Would you help me with update query?
$result = $conn->query($sql_user);
if (isset($result->num_rows) > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
$action_type=$row['action_type'];// Value will be aMan,bMan, cMan
$action_points=$row['action_points']; //10, 20, 30
}
}
$sql = "UPDATE man SET aMan='$action_points',bMan='$action_points', cMan='$action_points' where user_id='$user_id'";
$result = $conn->query($sql);
Update table

Answer 1

You are selecting from select drop down it means it will pass the value, that you have either aMan, bMan or cMan.
so you can do it like this,
$action_type = $_GET['action_type'];
$sql = "update man set `$action_type` = '$action_value' where id = $user_id";
Above is an example.

Answer 2

Firstly, you should replace if (isset($result -> num_rows) >0 ) with if(isset($result)) && ($result->num_rows>0)) .The first condition returns the number of rows (which at the least is 0) and then checks if it is set. Thus, isset will always return true, even when $result is not set. The second condition solves this problem
You have the type of list to update, why don't you use it?
For eg:
$result = $conn->query($sql_user);
if(isset($result)) && ($result->num_rows>0)) {
// output data of each row
while($row = $result->fetch_assoc()) {
$action_type=$row['action_type'];// Value will be aMan,bMan, cMan
$action_points=$row['action_points']; //10, 20, 30
}
}
$sql = "UPDATE man SET $action_type = $action_points WHERE user_id='$user_id'";
$result = $conn->query($sql);
This shall automatically update the required column

Answer 3

U should use AND in your query
UPDATE man SET aMan='$action_points' AND bMan='$action_points' AND cMan='$action_points' where user_id='$user_id'"
Or use several update query it means once update aMan row then a query for bMan row and so on.

Answer 4

The issue is because you are updating the three column at a time, you have to make it conditional like:
$action_type=$row['action_type'];// Value will be aMan,bMan, cMan
$action_points=$row['action_points']; //10, 20, 30
$column = '';
if($action_type == 'aMan'){
$column = 'aMan';
}
else if($action_type == 'bMan'){
$column = 'bMan';
}
else if($action_type == 'cMan'){
$column = 'cMan';
}
$sql = "UPDATE man SET ".$column." = '".$action_points."' where user_id='$user_id'";