Kotlin: Listen to database changes

Return real-time data from your table as a Flow.

• Realtime is disabled by default for new tables. You can turn it on by managing replication.
• selectAsFlow and selectSingleValueAsFlow will emit the initial data and then listen for changes.
• Takes in a filter parameter to filter the data and a primaryKey parameter to cache the data by the primary key.
• This method requires both the Realtime and Postgrest plugins to be installed.
• The type parameter T must be a serializable class.
• If you want more control over the realtime updates, you can use the Realtime plugin directly.

Parameters

• primaryKey

  (Required)

  The primary key to cache the data by. Can be a property reference or a custom primary key.

• channelName

  (Optional)

  The name of the channel to use for the realtime updates. If null, a channel name following the format "schema:table:id" will be used

• filter

  (Optional)

  The filter to apply to the data.

Examples

Listen for changes in multiple rows

val flow: Flow<List<Country>> = supabase.from("countries").selectAsFlow(Country::id)
flow.collect \{
    for (country in it) \{
        println(country.name)
    \}
\}

Listen for changes in multiple rows with a filter

val flow: Flow<List<Country>> = supabase.from("countries").selectAsFlow(
    Country::id,
    filter = FilterOperation("name", FilterOperator.ILIKE, "a%")
)
flow.collect \{
    for (country in it) \{
        println(country.name)
    \}
\}

Listen for changes in a single row

val flow: Flow<Country> = supabase.from("countries").selectSingleValueAsFlow(Country::id) \{
    //You can use the same filter methods as in the `select` method, but the result is limited to a single row
    Country::id eq 1
    //or
    eq("id", 1)
\}
flow.collect \{
    println("My country is $it")
\}