One very useful feature of spreadsheets is sorting. However, we have to be sure Sheets knows which data to sort and which data to leave in place.

To do thisDo this
Lock header rows in placeClick on the row, and choose View ⇒ Freeze ⇒ Up to current row.
Sort the whole sheetClick on the column, and choose Data ⇒ Sort sheet by column.
Sort part of the sheetSelect the region to sort, and choose Data ⇒ Sort range by column.
    ➜ Try it
  1. Lock the three header rows in place.
  2. Sort the table by purchaser, and then by date.