Question

So I am working on a fairly small script for the company I work at the help us manage our servers better. I don’t use MySQL too often though so I am a bit confused on what would be the best path to take.

I am doing something like this…

$sql = "CREATE TABLE IF NOT EXISTS Servers
    (
        MachineID int NOT NULL AUTO_INCREMENT,
        PRIMARY KEY(MachineID),
        FirstName varchar(32),
        LastName varchar(32),
        Datacenter TINYINT(1),
        OperatingSystem TINYINT(1),
        HostType TINYINT(1)
    )";

$result = mysql_query($sql,$conn);
check ($result);

$sql = "CREATE TABLE IF NOT EXISTS Datacenter
    (
        DatacenterID int NOT NULL AUTO_INCREMENT,
        PRIMARY KEY(DatacenterID),
        Name varchar(32),
        Location varchar(32)
    )";

$result = mysql_query($sql,$conn);
check ($result);

Basically inside the Servers table, I will be storing the index of an entry in another table. My concern is that if we remove one of those entries, it will screw up the auto incremented indexes and potentially cause a lot of incorrect data.

To explain better, lets say the first server I add, the Datacenter value is 3 (which is the DatacenterID), and we remove the id 1 (DatacenterID) Datacenter at a later time.

Is there a good way to do this?

Answer 1

Auto increment only has an effect on inserting new rows into a table. So you insert three records into database and they get assigned ids of 1, 2, and 3. Later you delete id 1, but the records at id 2 and 3 are unchanged. This says nothing of any of the server records that might be trying to reference the database id 1 record though that is now missing.