Each row has the same random number being inserted - php

Question

I'm looking to insert random numbers into each column in a database.
The issue that is occuring is that each column for some reason has the same random generated value being passed inside.
$sql = "SELECT * FROM players";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
$targScore = 3;
while($row = $result->fetch_assoc()) {
$target = 3; // The target number the sequence is adding up to
$n = 4; // Max numbers within sequence
while ($n) {
if (1 < $n--) {
$addend = rand(0, $target - ($n - 1));
$target -= $addend;
$num[] = $addend;
} else {
$num[] = $target;
}
}
/* Rows to update */
/* Output looks like:
[0] = 1
[1] = 2
[0] = 0
[0] = 1
*/
$changeScore = "UPDATE players SET doja='$num[0]' WHERE score='$targScore'";
$conn->query($changeScore);
$changeScore = "UPDATE players SET 7acres='$num[1]' WHERE score='$targScore'";
$conn->query($changeScore);
$changeScore = "UPDATE players SET tweed='$num[2]' WHERE score='$targScore'";
$conn->query($changeScore);
$changeScore = "UPDATE players SET bickel='$num[3]' WHERE score='$targScore'";
$conn->query($changeScore);
}
}
The data looks like: https://imgur.com/a/nhhZDVo
What I need is that each loop, it will run the randomizer again but change the numbers its inserting so that each row will have different numbers.

Answer 1

You need to first get a list of all the rows that meet the score condition. Then you have to update them one by one, so you can set different random values in each.
$select_stmt = $conn->prepare("SELECT id FROM players WHERE score = ?");
$select_stmt->bind_param("i", $targScore);
$select_stmt->execute();
$res = $select_stmt->get_result();
$update_stmt = $conn->prepare("UPDATE players SET doja = ?, 7acres = ?, tweed = ?, bickel = ? WHERE id = ?");
$update_stmt->bind_param("iiiii", $doja, $acres, $tweed, $bickel, $id);
$target = 3;
while ($row = $res->fetch_assoc()) {
$n = 4;
$num = [];
while ($n) {
if (1 < $n--) {
$addend = rand(0, $target - ($n - 1));
$target -= $addend;
$num[] = $addend;
} else {
$num[] = $target;
}
}
[$doja, $acres, $tweed, $bickel] = $num;
$id = $row['id'];
$update_stmt->execute();
}
There's also no need to use four UPDATE statements to update 4 columns in the same rows.

Answer 2

MySQL has a rand() function https://dev.mysql.com/doc/refman/5.7/en/mathematical-functions.html#function_rand
(Note the warning that it's not perfectly random / security secure, but nor is PHPs rand()).
If you do not need to know what the values are, you can simply do UPDATE myCol=FLOOR(RAND() * 200) WHERE myConditionalField=MyCondition
This will allocate a random number from 0 to 199; examples in the MySQL manual (linked above) as to how to set a range, e.g. FLOOR(7 + (RAND() * 5)) gives an integer from 7 to 11.