What kind of structure optimizes the use of a Link?
Field type Label is recommended to be used only in the cycle table to quickly fetch data from fields within the cycle.
It is highly recommended to avoid using labels anywhere else.
If you do not use a label, the code looks like this:
=: select(table: 'table_in_cycle'; field: 'field_in_cycle')
Why should we be careful with Link fields?
It is very easy to loop the scheme.
Why is it better not to use a Llink for Select fields with "individual calculation for each row"?
In this case, the select will be calculated for each row, which will result in a heavy load on the server.
Does the change in the Link cause the change in the main field?
No.
For this, an appropriate type (not a label) is taken and a binding of code and action code is made. The code is as described above, and the action code is as follows:
a1=: set(table: 'table_in_cycle'; field: 'field' = $#nfv)
a2=: clear(table: $#ntn; field: $#nf; where: 'id' = #id)
The logic is that when a change occurs, set is triggered, but the field goes into manual value mode, so clear is used to detach it.