How can I insert data into a Room database using Android Kotlin?

If you’re looking to insert data into a Room database in Android using Kotlin, this guide is for you! Room is a popular SQLite-based database library that provides an easy-to-use and flexible solution for managing local data in your Android apps.

Let’s dive in!

Prerequisites

First, make sure you have the following prerequisites in place:

1. Familiarity with Kotlin programming language and basic Android development concepts.
2. Room library added to your project (you can add it via Gradle or Maven). For example, for Gradle, include this line in your build.gradle file:

   <h2>   implementation "androidx.room:room-runtime:2.3.0"</h2>
   <h2>   kapt "androidx.room:room-compiler:2.3.0"</h2>

Setting Up Your Data Model

Create a new Kotlin data class that represents the entity you want to store in your database. For instance, let’s assume we are going to create an AppDatabase and insert a User entity.

@Entity(tableName  "user")
data class User(
<h2>    @PrimaryKey(autoGenerate  true) val id: Int?,</h2>
<h2>    val name: String,</h2>
<h2>    val age: Int</h2>
)

Defining Your DAO (Data Access Object)

Create an interface for the Data Access Object (DAO), which will define methods to interact with the database. For our example, let’s create a UserDao.

<h2>@Dao</h2>
interface UserDao {
    @Insert(onConflict  OnConflictStrategy.<h2>REPLACE)</h2>
<h2>    suspend fun insertUser(user: User): Long</h2>
}

Creating Your Database and DAO Component

Create a companion object inside your AppDatabase class to instantiate the Room database using the Room.databaseBuilder() method, passing in your App’s context and your UserDao.

<h2>@Database(entities  [User::class], version  1)</h2>
abstract class AppDatabase : RoomDatabase() {
<h2>    abstract fun userDao(): UserDao</h2>

    companion object {
<h2>        @Volatile</h2>
<h2>        private var INSTANCE: AppDatabase?  </h2>null




<h2>        fun getDatabase(context: Context): AppDatabase {</h2>
<h2>            return INSTANCE ?: synchronized(this) {</h2>
                val instance  Room.databaseBuilder(
                    context.applicationContext,
<h2>                    AppDatabase::class.java,</h2>
                    "app_database"
                )
                    .build()
                INSTANCE  instance
                instance
            }
        }
    }
}

Inserting Data into Your Database

Finally, to insert data into your database, call the UserDao‘s insertUser() method and pass in an instance of your User class.

suspend fun insertUser(user: User) {
    val db  AppDatabase.getDatabase(context).also {
        it.open()
    }
    val userDao  it.userDao()
    userDao.insertUser(user)
}

Conclusion

In this guide, we learned how to insert data into a Room database using Android Kotlin. We covered the prerequisites, setting up our data model, defining a DAO, creating the database and DAO component, and finally, inserting data into the database.