Question

I need to run a query on 2 legacy tables but both the join columns are not the primary key, by example is clearer:

The 2 one-to-one domain classes:

class DocumentStatus {
   String id
   String messageID

   static hasOne = [activity: Activity]

   static constraints = {
      activity unique: true
   }

   static mapping = {
       datasource 'messages'
       table 'DocumentStatus'
       cache usage: 'read-only'
       version false
       id column: 'UniqueID', generator: 'assigned'

       messageID column: 'MessageID', insertable: false, updateable: false
       activity column: 'MessageID', ignoreNotFound: true, cache: true, /*lazy: false, */fetch: 'join'
   }
}

and

class Activity {

   String id
   String messageId

   DocumentStatus documentStatus

   static belongsTo = [DocumentStatus]

   static mapping = {
      datasource 'messages'
      version false
      cache usage: 'read-only'
      table 'Activity'

      id column: 'aid', generator: 'assigned'

      messageId column: 'messageid', insertable: false, updateable: false

      documentStatus column: 'messageid', cache: true
   }

   static constraints = {
      documentStatus unique: true
   }
}

The SQL run is (only essential part shown here):

"inner join activity activity_a1_ on this_.uniqueid=activity_a1_.messageid " 

but what I need is to change the join column on DocumentStatus aka “this_” to be “messageId”.

The where clause basically is:

def query = DocumentStatus.where {
   dateTime >= dateFrom && dateTime <= dateTo &&
      status in docStatusList
}

if (buyerId) {
   query = query.where {
      activity.senderId == buyerId
   }
}
def results = query.list(sort: "dateTime", max: 100)

I’ve tried various combinations but can’t get the comparison to be messageId on both sides of the join.

Answer 1

This was resolved by adding a new domain class mapped to a table that has messageId as its PK, this then acts as the master which the other classes hang from:

class Content {
   String id
   String messageID

   static hasMany = [docStatus: DocumentStatus, activity: Activity]

   static mapping = {
    datasource 'messages' // If using multiple sources, specify
    table 'Content' // Table to map to
    cache usage: 'read-only' // If read-only
    version false  // no optimistic locking in these tables
    sort dateTime: "desc"

    // Map the ID column
    id column: 'MessageID', generator: 'assigned'
    // Map all other columns

    messageID column: 'MessageID', insertable: false, updateable: false

    docStatus column: 'MessageID', ignoreNotFound: true, cache: true, fetch: 'join'
    activity column: 'MessageID', ignoreNotFound: true, cache: true, fetch: 'join'
}

}

I’m still not sure why the original issue was there (perhaps this user is in error 🙂 ), surely I can join DomainA.FK = DomainB.FK. In the end this approach for my case actually was a better solution anyway by starting with the class with the PK and branching out on DomainA.PK = DomainB.FK

Hope that helps someone