Before relationships, a repository had a level that is single of. All calculations that are constant that standard of information. As an example SUM(1) came back the total number of documents when you look at the dining table.
In a data that are multi-table with relationships, there are lots of degrees of information. A constant calculation such as SUM(1) features its own degree of information, really an individual line, and returns “1”.
The constant adopts the level of detail of that field’s table if a constant is used in a calculation that contains a field.
As an example, the following calculation, if summed within the view, matters the amount of fiction publications (due to the fact genre field is through the guide dining table).
Considering that the known amount of information with this calculation is Book, it’s put appropriately when you look at the information pane.
Trick: replace the degree of information of a continuing with a non-null real condition from a far https://datingranking.net/escort-directory/augusta/ more table that is granular
Aside from the # of Fiction Books, assume we wished to determine the # of Fiction Books Sold. While Harry Potter together with Philosopher’s rock is a book that is single it is offered 120 copies. The cardinality with this relationship is numerous product sales for one book.
We are able to calculate # of Fiction Books Sold with the addition of the illness ISBN (product sales) = ISBN (product sales) to your calculation that is previous.
Although this condition does not replace the worth of the line as it is constantly real, it changes the degree of information regarding the calculation.
Due to the one-to-many relationship between Books and product sales, the degree of information regarding the joined dining table is product sales. The level of detail of the joined table, the meaning of “1” changes from a book to a book sold since the constant adopts. (더 보기…)