How to apply constraints to whole grades

Let's take a case, when you wish to specify constraints, that all "Music" lessons from each grade must be placed on the same day in the week. It means that all classes from 5th grade (5A, 5B, ...) must have these lessons in the same day. Similar for all classes from 6th, 7th and 8th grade.

You have two options:

1. Several relations - one for each grade

Create advanced card relationships - "Max days per week" with these parameters:
- set maximum to "1" - it means max day per week
- apply globally - because you want the software to include all lessons from the all selected classes
- select all classes from the same grade - e.g. 8.A, 8.B and 8C. for 8th grade.
- select subject "Music"

Then you would need to add same card relationships also for other classes. Use "Copy" button and just adjust selected classes.

Note
- use this solution, if each grade has different number of music lessons per week, or if setting grades for each class is more complicated for you than creating more similar relations.

2. One relation - for all classes at once

At first you have to specify grade for each class. Please, see this article: How to specify class grade

Then create similar advanced card relationship as mentioned above - "Max days per week" with following parameters.
- set maximum to "1"
- apply to grades of selected classes - then the software will internally break the selected cards into groups for each grade and apply the constraint to each group (so for each grade):
- select all classes - so just leave default setting
- select subject "Music"

Note
- The advantage of this second approach is that you just need to input one card relationship instead of possible 10 (one for each grade). If you have special requirements that need 2-3 card relationships for each grade, this can be even more helpful. Not to mention the possible errors in inputting 30 card relationships.
- if you select only some classes the software first builds a group of cards and only then divides it by grades. So if you omit one class, its cards will simply not be affected by this card relationship.