Create LineNum by HdrNum in a conversion effort

[feinj]

I am in desperate need of some help here.

I have a situation where I must convert data in an existing access database for use in a new database. The existing data has multiple line entries for the same header number, but has not identified each of those line entries with a line number.

I need to create a query that will automatically create the line number for each line entry, to restart at number 1 each time the header number changes.

I would greatly appreciate any help with this problem.

I have uploaded a small example of the data.

Thanks in advance for your help.

 

[pbaldy]

Search on "ranking" and you should find two general techniques: subquery or DCount. Either would use a criteria that matched HdrNum and counted ID <= the current value.