How to "put" LocalDate into SQLite DataBase

Question

I need to insert a Date Field into an SQLite Database.

I am using Kotlin and I chose LocalDate class to handle Date.

I've created a class which has a field LocalDate:

data class Pillola(..., val startDay: LocalDate = LocalDate.now())

Then I've tried to put data into the db using ContentValues as below:

    val values = ContentValues().apply{
        put(COLUMN_START_DAY, pillola.startDay)
    }

But I get error:

How can I fix or what other way can I use?

Answer 1

Use LocalDate without Room

You can use the LocalDate.toString() method.

It will store the date in a ISO-8601 format as mentioned in the documentation

In your exemple, it will be the following

val values = ContentValues().apply{
        put(COLUMN_START_DAY, pillola.startDay.toString())
    }

ContentValues cannot have other types as mentioned in your error (Boolean, Byte, ByteArray, Double, Float, Int, Long, Short, String)

When retrieving the string from your database you can simply use LocalDate.parse(String) to instantiate the string back to the LocalDate.

Use LocalDate with Room

Assuming you are using the Android ORM Room

If you have an entity having a LocalDate

@Entity(tableName = "my_entity")
data class MyEntity(
    val date: LocalDate
)

You can use a LocalDate only if you registered a Converter that will automatically store it as a string and retrieving it as a LocalDate

class LocalDateConverter {
    @TypeConverter
    fun localDateToString(localDate: LocalDate): String = localDate.toString()

    @TypeConverter
    fun stringToDateTime(localDate: String): LocalDate = LocalDate.parse(localDate)
}

Don't forget to register the convert using the @TypeConvertersannotation

@TypeConverters(LocalDateConverter::class)
abstract class MyDatabase : RoomDatabase()