How to add, delete and check existence with LINKSET in OrientDB?

Question

I am using OrientDB server side Javascript functions to define business logic. My query is how add, delete and check for existence with LINKSET in Javascript functions of OrientDB ?

Just for example, if my company.employees = [#4:1, #4:5, #4:3]

1. How can I add #4:6 to linkset ? After addition it should be [#4:1, #4:5, #4:3, #4:6]

2. How can I delete #4:5 from linkset ? After deletion it should be [#4:1, #4:3, #4:6]

3. If I add #4:1 again to linkset, will it check for duplicate and return error or do I need to check problematically before adding to linset ? If I need to do it, how to do it ?

I am sure there must be some methods to add, delete and check existence on linkset & linkmap, I am not just aware of those.

Any pointers will be helpful.

Answer 1

Look at the official documentation: https://github.com/orientechnologies/orientdb/wiki/SQL-Update#example-3-add-a-value-into-a-collection. So:

1) If your record has RID #13:33:

update #13:33 add company.employees = #4:6

2) The same (https://github.com/orientechnologies/orientdb/wiki/SQL-Update#example-4-remove-a-value-from-a-collection):

update #13:33 remove company.employees = #4:5

3) With set you cannot have duplicates, so if you add the same item multiple times, it's simply ignored with no errors.

Answer 2

The syntax has changed in OrientDB v3.0, according to this post:

Now, to add an element to the linkset you need to use the concatenation syntax which is here. http://orientdb.com/docs/3.0.x/sql/SQL-Syntax.html in Array concatenation

So your add example would be:

update #13:33 set company.employees= company.employees || #4:5

Remove has not changed so syntax is still:

update #13:33 remove company.employees = #4:5