How can I get the auto incrementing field name or the primary key fieldname from a mysql table?

auto-increment, mysql, php, primary-key

Solution

You can get the table information using the `SHOW COLUMNS FROM table`. Something like this:

$res = $mysqli->query('SHOW COLUMNS FROM tablename');

while($row = $res->fetch_assoc()) {
  if ($row['Extra'] == 'auto_increment')
    echo 'Field with auto_increment = '.$row['Field'];
  if ($row['Key'] == 'PRI')
    echo 'Field with primary key = '.$row['Field'];
}

Problem

In PHP, how do I get the field name of the field that's been set as to auto increment when a new rec is added to it? In most cases, it's the same as the PRIMARY_KEY of the table but not necessarily always. So this question has 2 parts with the second one branching into a 3rd part. 1- How to get the name of the auto-incrementing field name... 2- How to get the name of the primary_key field name... 2.1 How to get the primary_key(s) info when a table uses more than one field as its primary key...

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