77.4 Creating the Data Access Object
With the product entity defined, the next step is to create the DAO interface. Referring once again to the Project tool window, right-click on the app -> java -> com.ebookfrenzy.roomdemo entry and select the New -> Kotlin File/Class menu option. In the new class dialog, enter ProductDao into the Name field and select Interface from the list as highlighted in Figure 77-1:
Figure 77-1
Click on OK to generate the new interface and, with the ProductDao.kt file loaded into the code editor, make the following changes:
package com.ebookfrenzy.roomdemo
import androidx.lifecycle.LiveData
import androidx.room.Dao
import androidx.room.Insert
import androidx.room.Query
@Dao
interface ProductDao {
@Insert
fun insertProduct(product: Product)
@Query("SELECT * FROM products WHERE productName = :name...