I wish to be able to enforce uniqueness on a per-u...
# prisma-whats-newv
valein
09/06/2017, 9:22 AMI wish to be able to enforce uniqueness on a per-user basis. For example; I have a company type with a name field. Each logged user may have several companies related to them. The name of the company is set by the user on company creation. When running the createCompany mutation I want to check that a name with the specified name has not already been created by that user. In an SQL database I would’ve used a composite primary key to make this kind of uniqueness but in graphcool I don’t know how to do it. Suggestions?
d
dankent
09/06/2017, 9:33 AMThere are two options for this. Right now, you can use a Request Pipeline function to apply the constraint. You'd want to use the Transform_Argument pipeline step, as this is triggered before anything is written to the database
dankent
09/06/2017, 9:33 AMWhen schema extensions come out of beta (or if you join the beta) you could write your own custom mutation that includes the logic that you want.
v
valein
09/06/2017, 9:34 AMHow can I join beta? 🙂
d
dankent
09/06/2017, 9:34 AMI'd recommend a pipeline function for this use case though, as you are only adding a constraint on the existing mutation rather than changing the bahviour of it whokesale
dankent
09/06/2017, 9:34 AMyou need to ask @nilan for access to the schema extensions beta
dankent
09/06/2017, 9:36 AMThinking about it, you may also be able to use a permission query to prevent users from adding a company with a name that they have already added. That would be more efficient than using either kind of function.
dankent
09/06/2017, 9:37 AMYour permission query (on create of Company and requiring authentication) would look something like this:
dankent
09/06/2017, 9:37 AMquery ($input_name: String!, $user_id: ID!) {
SomeUserExists(
filter: {
id: $user_id,
companies_none:{
name: $input_name
}
}
)
}
v
valein
09/06/2017, 9:37 AMa create permission query, right. Need to refresh my memory of how those work
valein
09/06/2017, 9:38 AMaha!
d
dankent
09/06/2017, 9:38 AMSo bascially we are saying that for a company to be added, there must exist a user with the same Id as the current user who has no company with a matching name
v
valein
09/06/2017, 9:39 AMYup, I’m testing right away. Brb 🙂
valein
09/06/2017, 9:40 AMYay, that seems to do it!! Much easier than I believed it to be! Thanks a lot dankent!
d
dankent
09/06/2017, 9:40 AMno worries