for idx, foreignField := range foreignFields {
		// use same data type for foreign keys
		schema.Relationships.Mux.Lock()
		if schema != foreignField.Schema {
			foreignField.Schema.Relationships.Mux.Lock()
		}
		if copyableDataType(primaryFields[idx].DataType) {
			foreignField.DataType = primaryFields[idx].DataType
		}
		foreignField.GORMDataType = primaryFields[idx].GORMDataType
		if foreignField.Size == 0 {