PHP MySQL Table loop

[waddledoo]

I am trying to place a unique number into a mysql table.

 

Currently, my code generates a random number, then is supposed to scan through the table for that number.

If the code finds that number already in the table, it generates a new random number and repeats the process.

I have commented my code for the purpose of this help forum:

 

        $result = mysqli_query($link,"SELECT * FROM testTable");

do
{
	$end = true; //prepares end of loop
	$idNum = rand(1,10); //rand(1,999999);  <-- for testing purposes I have reduced the number generated
	$idNumTx = (string)$idNum;

                //loop through the rows
	while ($row = mysqli_fetch_assoc($result))
	{
		if ($row['idNum'] = $idNum) //check if the random number equal to this row
		{
			$end = false; //prep end of loop repeat
			echo $idNumTx; //display rand number that failed for testing purposes
			echo " NO! "; //display error for testing purposes
		}
	}
} while(!$end);

 

I know I must be doing something wrong, as when I run this, it runs the if statement within the while loop always executes, and I get an output like:

1 NO! 1 NO! 1 NO! 1 NO! 1 NO! 1 NO! 5 Win

 

Win is when it places the value before it, in this case 5, into the table. However, the value of 5 might already be in the table and it doesn't seem to matter.

I execute the code multiple times, and it seems to increase the number of "# NO!" almost (but not every) time. However, each time ALL of the "# NO!" are the same #, and the "# Win" just seems to be random (as it should be, but not unique).

 

Checking the table after shows me random numbers between 1 and 10 (as it should) in the correct field, but the are not unique. (Ex/ Both row 1 and 5 could have the same value, say 6)

 

I'm hopefully doing something simple wrong, so someone please point it out to me

[waddledoo]

I found a better way to accomplish what I wanted. I still don't understand what was wrong with my previous code, but the new code works perfectly:

 

        do
{
	$end = true;
	$idNum = rand(1,10);//rand(1,999999);
	$idNumTx = (string)$idNum;

	$testExists = mysqli_query($link,"SELECT idNum FROM test3 where idNum='$idNum'");
	$num = mysqli_num_rows($testExists);
	if ($num!=0)
	{
		$end = false;
	}
} while(!$end);

 

This code now queries the random number directly from the table, and will only complete the loop if the query returns nothing (if the #ofrows returned is 0)

 

This thread can be marked as solved, or deleted.

[PFMaBiSmAd]

Two == signs is a comparison operator. One = sign is an assignment operator. Your first code was assigning $idNum to $row['idNum'] in the if(){} statement, and then testing if the value that was assigned evaluated to a true or false.

[waddledoo]

Ah thankyou. More and more I see PHP is like C++. I was used to coding in python hehe