firebase-database/dev.gitlive.firebase.database/DatabaseReference

DatabaseReference

A Firebase reference represents a particular location in your Database and can be used for reading or writing data to that Database location.

This class is the starting point for all Database operations. After you've initialized it with a URL, you can use it to read data, write data, and to create new DatabaseReferences.

Properties

android

val DatabaseReference.android: DatabaseReference

val Query.android: Query

val DatabaseReference.android: DatabaseReference

val Query.android: Query

ios

val DatabaseReference.ios: FIRDatabaseReference

val Query.ios: FIRDatabaseQuery

val Query.js: Query

key

val key: String?

valueEvents

expect val valueEvents: Flow<DataSnapshot>

Functions

child

fun child(path: String): DatabaseReference

Get a reference to location relative to this one

childEvents

expect fun childEvents(vararg types: ChildEvent.Type = arrayOf(ADDED, CHANGED, MOVED, REMOVED)): Flow<ChildEvent>

endAt

expect fun endAt(value: Boolean, key: String? = null): Query

expect fun endAt(value: Double, key: String? = null): Query

expect fun endAt(value: String, key: String? = null): Query

Creates a query constrained to only return child nodes with a value less than or equal to the given value, using the given orderBy directive or priority as default.

equalTo

expect fun equalTo(value: Boolean, key: String? = null): Query

expect fun equalTo(value: Double, key: String? = null): Query

expect fun equalTo(value: String, key: String? = null): Query

Creates a query constrained to only return child nodes with the given value.

limitToFirst

expect fun limitToFirst(limit: Int): Query

Creates a query with limit and anchor it to the start of the window.

limitToLast

expect fun limitToLast(limit: Int): Query

Creates a query with limit and anchor it to the end of the window.

onDisconnect

fun onDisconnect(): OnDisconnect

Provides access to disconnect operations at this location

orderByChild

expect fun orderByChild(path: String): Query

Creates a query in which child nodes are ordered by the values of the specified path.

orderByKey

expect fun orderByKey(): Query

Creates a query in which child nodes are ordered by their keys.

orderByValue

expect fun orderByValue(): Query

Creates a query in which nodes are ordered by their value

push

fun push(): DatabaseReference

Create a reference to an auto-generated child location. The child key is generated client-side and incorporates an estimate of the server's time for sorting purposes. Locations generated on a single client will be sorted in the order that they are created, and will be sorted approximately in order across all clients.

removeValue

suspend fun removeValue()

Set the value at this location to 'null'

runTransaction

suspend fun <T> runTransaction(strategy: KSerializer<T>, buildSettings: EncodeDecodeSettingsBuilder.() -> Unit = {}, transactionUpdate: (currentData: T) -> T): DataSnapshot

Run a transaction on the data at this location.

setValue

inline suspend fun <T> ~~setValue~~(value: T?, encodeDefaults: Boolean)

inline suspend fun <T> setValue(value: T?, buildSettings: EncodeSettings.Builder.() -> Unit = {})

suspend fun <T> ~~setValue~~(strategy: SerializationStrategy<T>, value: T, encodeDefaults: Boolean)

inline suspend fun <T> setValue(strategy: SerializationStrategy<T>, value: T, buildSettings: EncodeSettings.Builder.() -> Unit = {})

startAt

expect fun startAt(value: Boolean, key: String? = null): Query

expect fun startAt(value: Double, key: String? = null): Query

expect fun startAt(value: String, key: String? = null): Query

Creates a query constrained to only return child nodes with a value greater than or equal to the given value, using the given orderBy directive or priority as default.

updateChildren

suspend fun ~~updateChildren~~(update: Map<String, Any?>, encodeDefaults: Boolean)

inline suspend fun updateChildren(update: Map<String, Any?>, buildSettings: EncodeSettings.Builder.() -> Unit = {})

Update the specific child keys to the specified values. Passing null in a map to updateChildren() will remove the value at the specified location.