Solution for Fixing Binding Issues with Array in JSON Field in HasManyRelation

[UnRealSKY]

When relation: Model.HasManyRelation is used and join.from is a JSON field with its content being an array, I observed that withGraphFetch using builder.toKnexQuery().toString() can actually query the correct rows. However, it fails to bind back to own. To address this, I modified the onAfter2 method in RelationFindOperation.js.

import _ from 'lodash'

class RelationFindOperation extends FindOperation {
  /** ... */
  getOwnKeys(ownerProp, own) {
    const ownerKeysHandlers = [
      {
        match: (ownerProp, own) => ownerProp.props.length > 1,
        handler: (ownerProp, own) => ownerProp.propKey(own)
      },
      {
        match: (ownerProp, own) => _.isArray(own[ownerProp.props[0]]),
        handler: (ownerProp, own) =>
          _.map(own[ownerProp.props[0]], (ownProp) =>
            ownerProp.propKey({ own, [ownerProp.props[0]]: ownProp })
          )
      },
      {
        match: () => true,
        handler: (ownerProp, own) => ownerProp.propKey(own)
      }
    ]
    for (const { match, handler } of ownerKeysHandlers) {
      const matched = match(ownerProp, own)
      if (!matched) {
        continue
      }
      return handler(ownerProp, own)
    }
  }

  onAfter2(_, related) {
    const isOneToOne = this.relation.isOneToOne()

    if (this.assignResultToOwner && this.owner.isModels) {
      const owners = this.owner.modelArray
      const relatedByOwnerId = new Map()

      for (let i = 0, l = related.length; i < l; ++i) {
        const rel = related[i]
        const key = this.relation.relatedProp.propKey(rel)
        let arr = relatedByOwnerId.get(key)

        if (!arr) {
          arr = []
          relatedByOwnerId.set(key, arr)
        }

        arr.push(rel)
      }
    }

    for (let i = 0, l = owners.length; i < l; ++i) {
      const own = owners[i]
      const keys = this.getOwnKeys(this.relation.ownerProp, own)

      for (const key of keys) {
        const related = relatedByOwnerId.get(key)

        if (isOneToOne) {
          own[this.relationProperty] = (related && related[0]) || null
        } else {
          own[this.relationProperty] = [].concat(
            own[this.relationProperty] || [],
            related || []
          )
        }
      }
    }

    return related
  }
  
  /** ... */
}

[kapouer]

It would be great to make a PR that references this issue.