CommonPowerSyncDatabase

Extends

• BaseObserverInterface<PowerSyncDBListener>.SqlExecutor.DBGetUtils

Properties

Property	Modifier	Type	Description	Inherited from
closed	readonly	boolean	Returns true if the connection is closed.	-
currentStatus	readonly	SyncStatus	Current connection status.	-
execute	public	<T>(query, params?) => Promise<QueryResult<T>>	Execute a SQL write (INSERT/UPDATE/DELETE) query and optionally return results. When using the default client-side JSON-based view system, the returned result's rowsAffected may be 0 for successful UPDATE and DELETE statements. Use a RETURNING clause and inspect result.rows when you need to confirm which rows changed.	SqlExecutor.execute
executeBatch	public	(query, params?) => Promise<QueryResult<never>>	Execute a write query (INSERT/UPDATE/DELETE) multiple times with each parameter set and optionally return results. This is faster than executing separately with each parameter set.	SqlExecutor.executeBatch
executeRaw	public	(query, params?) => Promise<RawQueryResult>	Execute a SQL write (INSERT/UPDATE/DELETE) query directly on the database without any PowerSync processing. This bypasses certain PowerSync abstractions and is useful for accessing the raw database results.	SqlExecutor.executeRaw
logger	readonly	PowerSyncLogger	-	-
ready	readonly	boolean	-	-
schema	readonly	Schema	Schema used for the local database.	-
sdkVersion	readonly	string	-	-
triggers	readonly	TriggerManager	Experimental Alpha Allows creating SQLite triggers which can be used to track various operations on SQLite tables.	-

Accessors

connected

Get Signature

get connected(): boolean;

Whether a connection to the PowerSync service is currently open.

Returns

boolean

---

connecting

Get Signature

get connecting(): boolean;

Returns

boolean

---

database

Get Signature

get database(): DBAdapter;

The underlying database.

For the most part, behavior is the same whether querying on the underlying database, or on CommonPowerSyncDatabase.

Returns

DBAdapter

Methods

close()

close(options?): Promise<void>;

Close the database, releasing resources.

Also disconnects any active connection.

Once close is called, this connection cannot be used again - a new one must be constructed.

Parameters

Parameter	Type
options?	PowerSyncCloseOptions

Returns

Promise<void>

---

connect()

connect(connector, options?): Promise<void>;

Connects to stream of events from the PowerSync instance.

Parameters

Parameter	Type
connector	PowerSyncBackendConnector
options?	SyncOptions

Returns

Promise<void>

---

customQuery()

customQuery<RowType>(query): Query<RowType>;

Allows building a WatchedQuery using an existing WatchCompatibleQuery. The watched query will use the provided WatchCompatibleQuery.execute method to query results.

Type Parameters

Type Parameter
RowType

Parameters

Parameter	Type
query	WatchCompatibleQuery<RowType[]>

Returns

Query<RowType>

Example

// Potentially a query from an ORM like Drizzle
const query = db.select().from(lists);

const watchedTodos = powersync.customQuery(query)
.watch()
// OR use .differentialWatch() for fine-grained watches.

---

disconnect()

disconnect(): Promise<void>;

Close the sync connection.

Use CommonPowerSyncDatabase.connect to connect again.

Returns

Promise<void>

---

disconnectAndClear()

disconnectAndClear(options?): Promise<void>;

Disconnect and clear the database. Use this when logging out. The database can still be queried after this is called, but the tables would be empty.

To preserve data in local-only tables, set clearLocal to false.

Parameters

Parameter	Type
options?	DisconnectAndClearOptions

Returns

Promise<void>

---

get()

get<T>(sql, parameters?): Promise<T>;

Execute a read-only query and return the first result, error if the ResultSet is empty.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
sql	string	The SQL query to execute
parameters?	any[]	Optional array of parameters to bind to the query

Returns

Promise<T>

The first result matching the query

Throws

Error if no rows are returned

Inherited from

DBGetUtils.get

---

getAll()

getAll<T>(sql, parameters?): Promise<T[]>;

Execute a read-only query and return results.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
sql	string	The SQL query to execute
parameters?	any[]	Optional array of parameters to bind to the query

Returns

Promise<T[]>

An array of results

Inherited from

DBGetUtils.getAll

---

getClientId()

getClientId(): Promise<string>;

Get an unique client id for this database.

The id is not reset when the database is cleared, only when the database is deleted.

Returns

Promise<string>

A unique identifier for the database instance

---

getCrudBatch()

getCrudBatch(limit?): Promise<CrudBatch | null>;

Get a batch of CRUD data to upload.

Returns null if there is no data to upload.

Use this from the PowerSyncBackendConnector.uploadData callback.

Once the data have been successfully uploaded, call CrudBatch.complete before requesting the next batch.

Use the limit parameter to specify the maximum number of updates to return in a single batch.

This method does include transaction ids in the result, but does not group data by transaction. One batch may contain data from multiple transactions, and a single transaction may be split over multiple batches.

Parameters

Parameter	Type	Description
limit?	number	Maximum number of CRUD entries to include in the batch

Returns

Promise<CrudBatch | null>

A batch of CRUD operations to upload, or null if there are none

---

getCrudTransactions()

getCrudTransactions(): AsyncIterable<CrudTransaction, null>;

Returns an async iterator of completed transactions with local writes against the database.

This is typically used from the PowerSyncBackendConnector.uploadData callback. Each entry emitted by the returned iterator is a full transaction containing all local writes made while that transaction was active.

Unlike CommonPowerSyncDatabase.getNextCrudTransaction, which always returns the oldest transaction that hasn't been CrudTransaction.completed yet, this iterator can be used to receive multiple transactions. Calling CrudTransaction.complete will mark that and all prior transactions emitted by the iterator as completed.

This can be used to upload multiple transactions in a single batch, e.g with:

let lastTransaction = null;
let batch = [];

for await (const transaction of database.getCrudTransactions()) {
  batch.push(...transaction.crud);
  lastTransaction = transaction;

  if (batch.length > 10) {
    break;
   }
}

If there is no local data to upload, the async iterator complete without emitting any items.

Note that iterating over async iterables requires a polyfill for React Native.

Returns

AsyncIterable<CrudTransaction, null>

---

getNextCrudTransaction()

getNextCrudTransaction(): Promise<CrudTransaction | null>;

Get the next recorded transaction to upload.

Returns null if there is no data to upload.

Use this from the PowerSyncBackendConnector.uploadData callback.

Once the data have been successfully uploaded, call CrudTransaction.complete before requesting the next transaction.

Unlike CommonPowerSyncDatabase.getCrudBatch, this only returns data from a single transaction at a time. All data for the transaction is loaded into memory.

Returns

Promise<CrudTransaction | null>

A transaction of CRUD operations to upload, or null if there are none

---

getOptional()

getOptional<T>(sql, parameters?): Promise<T | null>;

Execute a read-only query and return the first result, or null if the ResultSet is empty.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
sql	string	The SQL query to execute
parameters?	any[]	Optional array of parameters to bind to the query

Returns

Promise<T | null>

The first result if found, or null if no results are returned

Inherited from

DBGetUtils.getOptional

---

getUploadQueueStats()

getUploadQueueStats(includeSize?): Promise<UploadQueueStats>;

Get upload queue size estimate and count.

Parameters

Parameter	Type
includeSize?	boolean

Returns

Promise<UploadQueueStats>

---

init()

init(): Promise<void>;

Wait for initialization to complete. While initializing is automatic, this helps to catch and report initialization errors.

Returns

Promise<void>

---

onChange()

Call Signature

onChange(options?): AsyncIterable<WatchOnChangeEvent>;

This version of onChange uses AsyncGenerator, for documentation see CommonPowerSyncDatabase.onChangeWithAsyncGenerator. Can be overloaded to use a callback handler instead, for documentation see CommonPowerSyncDatabase.onChangeWithCallback.

Parameters

Parameter	Type
options?	SQLOnChangeOptions

Returns

AsyncIterable<WatchOnChangeEvent>

Example

async monitorChanges() {
  for await (const event of this.powersync.onChange({tables: ['todos']})) {
    console.log('Detected change event:', event);
  }
}

Call Signature

onChange(handler?, options?): () => void;

See CommonPowerSyncDatabase.onChangeWithCallback.

Parameters

Parameter	Type
handler?	WatchOnChangeHandler
options?	SQLOnChangeOptions

Returns

() => void

Example

monitorChanges() {
  this.powersync.onChange({
    onChange: (event) => {
      console.log('Change detected:', event);
    }
  }, { tables: ['todos'] });
}

---

onChangeWithAsyncGenerator()

onChangeWithAsyncGenerator(options?): AsyncIterable<WatchOnChangeEvent>;

Create a Stream of changes to any of the specified tables.

This is preferred over CommonPowerSyncDatabase.watchWithAsyncGenerator when multiple queries need to be performed together when data is changed.

Note: do not declare this as async *onChange as it will not work in React Native.

Parameters

Parameter	Type	Description
options?	SQLWatchOptions	Options for configuring watch behavior

Returns

AsyncIterable<WatchOnChangeEvent>

An AsyncIterable that yields change events whenever the specified tables change

---

onChangeWithCallback()

onChangeWithCallback(handler?, options?): () => void;

Invoke the provided callback on any changes to any of the specified tables.

This is preferred over CommonPowerSyncDatabase.watchWithCallback when multiple queries need to be performed together when data is changed.

Note that the onChange callback member of the handler is required.

Parameters

Parameter	Type	Description
handler?	WatchOnChangeHandler	Callbacks for handling change events and errors
options?	SQLOnChangeOptions	Options for configuring watch behavior

Returns

A dispose function to stop watching for changes

() => void

---

query()

query<RowType>(query): Query<RowType>;

Allows defining a query which can be used to build a WatchedQuery. The defined query will be executed with CommonPowerSyncDatabase#getAll. An optional mapper function can be provided to transform the results.

Type Parameters

Type Parameter
RowType

Parameters

Parameter	Type
query	ArrayQueryDefinition<RowType>

Returns

Query<RowType>

Example

const watchedTodos = powersync.query({
 sql: `SELECT photo_id as id FROM todos WHERE photo_id IS NOT NULL`,
 parameters: [],
 mapper: (row) => ({
   ...row,
   created_at: new Date(row.created_at as string)
 })
})
.watch()
// OR use .differentialWatch() for fine-grained watches.

---

readLock()

readLock<T>(callback): Promise<T>;

Takes a read lock, without starting a transaction. In most cases, CommonPowerSyncDatabase.readTransaction should be used instead.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type
callback	(db) => Promise<T>

Returns

Promise<T>

---

readTransaction()

readTransaction<T>(callback, lockTimeout?): Promise<T>;

Open a read-only transaction. Read transactions can run concurrently to a write transaction. Changes from any write transaction are not visible to read transactions started before it.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
callback	(tx) => Promise<T>	Function to execute within the transaction
lockTimeout?	number	Time in milliseconds to wait for a lock before throwing an error

Returns

Promise<T>

The result of the callback

Throws

Error if the lock cannot be obtained within the timeout period

---

registerListener()

registerListener(listener): () => void;

Parameters

Parameter	Type
listener	Partial<T>

Returns

() => void

Inherited from

BaseObserverInterface.registerListener

---

resolveTables()

resolveTables(
   sql, 
   parameters?, 
options?): Promise<string[]>;

Resolves the list of tables that are used in a SQL query. If tables are specified in the options, those are used directly. Otherwise, analyzes the query using EXPLAIN to determine which tables are accessed.

Parameters

Parameter	Type	Description
sql	string	The SQL query to analyze
parameters?	any[]	Optional parameters for the SQL query
options?	SQLWatchOptions	Optional watch options that may contain explicit table list

Returns

Promise<string[]>

Array of table names that the query depends on

---

syncStream()

syncStream(name, params?): SyncStream;

Create a sync stream to query its status or to subscribe to it.

Parameters

Parameter	Type	Description
name	string	The name of the stream to subscribe to.
params?	Record<string, any>	Optional parameters for the stream subscription.

Returns

SyncStream

A SyncStream instance that can be subscribed to.

---

updateSchema()

updateSchema(schema): Promise<void>;

Replace the schema with a new version. This is for advanced use cases - typically the schema should just be specified once in the constructor.

Cannot be used while connected - this should only be called before CommonPowerSyncDatabase.connect.

Parameters

Parameter	Type
schema	Schema

Returns

Promise<void>

---

waitForFirstSync()

waitForFirstSync(request?): Promise<void>;

Wait for the first sync operation to complete.

Parameters

Parameter	Type	Description
request?	| AbortSignal | { priority?: number; signal?: AbortSignal; }	Either an abort signal (after which the promise will complete regardless of whether a full sync was completed) or an object providing an abort signal and a priority target. When a priority target is set, the promise may complete when all buckets with the given (or higher) priorities have been synchronized. This can be earlier than a complete sync.

Returns

Promise<void>

A promise which will resolve once the first full sync has completed.

---

waitForReady()

waitForReady(): Promise<void>;

Returns

Promise<void>

A promise which will resolve once initialization is completed.

---

waitForStatus()

waitForStatus(predicate, signal?): Promise<void>;

Waits for the first sync status for which the status callback returns a truthy value.

Parameters

Parameter	Type
predicate	(status) => any
signal?	AbortSignal

Returns

Promise<void>

---

watch()

Call Signature

watch(
   sql, 
   parameters?, 
options?): AsyncIterable<QueryResult<SqliteRecord>>;

This version of watch uses AsyncGenerator, for documentation see CommonPowerSyncDatabase.watchWithAsyncGenerator. Can be overloaded to use a callback handler instead, for documentation see CommonPowerSyncDatabase.watchWithCallback.

Parameters

Parameter	Type
sql	string
parameters?	any[]
options?	SQLWatchOptions

Returns

AsyncIterable<QueryResult<SqliteRecord>>

Example

async *attachmentIds() {
  for await (const result of this.powersync.watch(
    `SELECT photo_id as id FROM todos WHERE photo_id IS NOT NULL`,
    []
  )) {
    yield result.rows?._array.map((r) => r.id) ?? [];
  }
}

Call Signature

watch(
   sql, 
   parameters?, 
   handler?, 
   options?): void;

See CommonPowerSyncDatabase.watchWithCallback.

Parameters

Parameter	Type
sql	string
parameters?	any[]
handler?	WatchHandler
options?	SQLWatchOptions

Returns

void

Example

onAttachmentIdsChange(onResult) {
  this.powersync.watch(
    `SELECT photo_id as id FROM todos WHERE photo_id IS NOT NULL`,
    [],
    {
      onResult: (result) => onResult(result.rows?._array.map((r) => r.id) ?? [])
    }
  );
}

---

watchWithAsyncGenerator()

watchWithAsyncGenerator(
   sql, 
   parameters?, 
options?): AsyncIterable<QueryResult<SqliteRecord>>;

Execute a read query every time the source tables are modified. Use SQLOnChangeOptions.throttleMs to specify the minimum interval between queries. Source tables are automatically detected using EXPLAIN QUERY PLAN.

Parameters

Parameter	Type	Description
sql	string	The SQL query to execute
parameters?	any[]	Optional array of parameters to bind to the query
options?	SQLWatchOptions	Options for configuring watch behavior

Returns

AsyncIterable<QueryResult<SqliteRecord>>

An AsyncIterable that yields QueryResults whenever the data changes

---

watchWithCallback()

watchWithCallback(
   sql, 
   parameters?, 
   handler?, 
   options?): void;

Execute a read query every time the source tables are modified. Use SQLOnChangeOptions.throttleMs to specify the minimum interval between queries. Source tables are automatically detected using EXPLAIN QUERY PLAN.

Note that the onChange callback member of the handler is required.

Parameters

Parameter	Type	Description
sql	string	The SQL query to execute
parameters?	any[]	Optional array of parameters to bind to the query
handler?	WatchHandler	Callbacks for handling results and errors
options?	SQLWatchOptions	Options for configuring watch behavior

Returns

void

---

writeLock()

writeLock<T>(callback): Promise<T>;

Takes a global lock, without starting a transaction. In most cases, CommonPowerSyncDatabase.writeTransaction should be used instead.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type
callback	(db) => Promise<T>

Returns

Promise<T>

---

writeTransaction()

writeTransaction<T>(callback, lockTimeout?): Promise<T>;

Open a read-write transaction. This takes a global lock - only one write transaction can execute against the database at a time. Statements within the transaction must be done on the provided Transaction interface.

Type Parameters

Type Parameter
T

Parameters

Parameter	Type	Description
callback	(tx) => Promise<T>	Function to execute within the transaction
lockTimeout?	number	Time in milliseconds to wait for a lock before throwing an error

Returns

Promise<T>

The result of the callback

Throws

Error if the lock cannot be obtained within the timeout period