mysql question... So I would like to auto populate a number, but I would like it to be based on another field. I'm not sure how to explain it other than using this example:

```
Field 1 | Field 2 (auto populate)
   1    |   1
   2    |   1
   2    |   2
   2    |   3
   3    |   1
   3    |   2
   2    |   4
   2    |   5

```

Is there a mysql function expression that can be added to the column?

I know I could do this in my Python script that is feeding the values, but I have to assume it will be faster if the function is baked into mysql.

**UPDATE:** 
Let me add some clarification...

Field 1 will get filled with a value from a script. 

There will be multiple entries of Field 1 that are the same number. 

I would like Field 2 to auto populate to have a unique number WITHIN that Field 1 number.