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Interface: ReadTransaction

ReadTransactions are used with query and subscribe and allows read operations on the database.

Hierarchy

Properties

clientID

Readonly clientID: string

Methods

get

get(key): Promise<undefined | ReadonlyJSONValue>

Get a single value from the database. If the key is not present this returns undefined.

Important: The returned JSON is readonly and should not be modified. This is only enforced statically by TypeScript and there are no runtime checks for performance reasons. If you mutate the return value you will get undefined behavior.

Parameters

NameType
keystring

Returns

Promise<undefined | ReadonlyJSONValue>


has

has(key): Promise<boolean>

Determines if a single key is present in the database.

Parameters

NameType
keystring

Returns

Promise<boolean>


isEmpty

isEmpty(): Promise<boolean>

Whether the database is empty.

Returns

Promise<boolean>


scan

scan(): ScanResult<string>

Gets many values from the database. This returns a ScanResult which implements AsyncIterable. It also has methods to iterate over the keys and entries.

If options has an indexName, then this does a scan over an index with that name. A scan over an index uses a tuple for the key consisting of [secondary: string, primary: string].

If the ScanResult is used after the ReadTransaction has been closed it will throw a TransactionClosedError.

Important: The returned JSON is readonly and should not be modified. This is only enforced statically by TypeScript and there are no runtime checks for performance reasons. If you mutate the return value you will get undefined behavior.

Returns

ScanResult<string>

scan<Options>(options?): ScanResult<KeyTypeForScanOptions<Options>>

Gets many values from the database. This returns a ScanResult which implements AsyncIterable. It also has methods to iterate over the keys and entries.

If options has an indexName, then this does a scan over an index with that name. A scan over an index uses a tuple for the key consisting of [secondary: string, primary: string].

If the ScanResult is used after the ReadTransaction has been closed it will throw a TransactionClosedError.

Important: The returned JSON is readonly and should not be modified. This is only enforced statically by TypeScript and there are no runtime checks for performance reasons. If you mutate the return value you will get undefined behavior.

Type parameters

NameType
Optionsextends ScanOptions

Parameters

NameType
options?Options

Returns

ScanResult<KeyTypeForScanOptions<Options>>