Secondary keys and SumIndexFields

The Playlist Line table default primary key was the one field Document No. In order for the primary key to be unique for each record, another field is needed. For a line table, the additional field is the Line No. field, which is incremented through C/AL code for each record. So, we'll change the key for table 50003 accordingly:

We know a lot of reporting will be done based on the data in the Radio Show Ledger. We also know we want to do reporting on data by Radio Show and by the type of entry (indpidual song, specific ad, and so on). So, we will add secondary keys for each of those, including a Date field so we can rapidly filter the data by Date. The reporting that is financial in nature will need totals of the Fee Amount field, so we'll put that in the SumIndexFields column for our new keys:

We know that to do the necessary listenership analysis, the listenership ledger needs an additional key combined with SumIndexFields for totaling listener statistics:

To utilize the SumIndexFields we have just defined, we will need to define corresponding FlowFields in other tables. We will leave that part of the development effort for the next chapter, where we are going to discuss Fields, FlowFields, and FlowFilters in detail.