getCrudBatch

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 limit to specify the maximum number of updates to return in a single batch. Default is 100.

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.