HasMany   RelationshipType = "has_many"     // HasManyRel has many relationship
	BelongsTo RelationshipType = "belongs_to"   // BelongsToRel belongs to relationship
	Many2Many RelationshipType = "many_to_many" // Many2ManyRel many to many relationship
	has       RelationshipType = "has"
)

type Relationships struct {
	HasOne    []*Relationship
	BelongsTo []*Relationship
	HasMany   []*Relationship
	Many2Many []*Relationship

		reflectValue := association.DB.Statement.ReflectValue
		rel := association.Relationship

		var oldBelongsToExpr clause.Expression
		// we have to record the old BelongsTo value
		if association.Unscope && rel.Type == schema.BelongsTo {
			var foreignFields []*schema.Field
			for _, ref := range rel.References {
				if !ref.OwnPrimaryKey {
					foreignFields = append(foreignFields, ref.ForeignKey)
				}
			}

			return assocDB.Updates(fkNil).Error
		case clause.OpDelete:
			return assocDB.Delete(assocModel).Error
		case clause.OpUpdate:
			return assocDB.Updates(setMap).Error
		}
	case schema.BelongsTo:
		switch op.Type {
		case clause.OpDelete:
			return base.Transaction(func(tx *DB) error {
				assocDB.Statement.ConnPool = tx.Statement.ConnPool
				base.Statement.ConnPool = tx.Statement.ConnPool