Class ReadRequest (3.3.0) 

ReadRequest(mapping=None, *, ignore_unknown_fields=False, **kwargs)

The request for Read][google.spanner.v1.Spanner.Read] and StreamingRead][google.spanner.v1.Spanner.StreamingRead].

Attributes

NameDescription
session str
Required. The session in which the read should be performed.
transaction google.cloud.spanner_v1.types.TransactionSelector
The transaction to use. If none is provided, the default is a temporary read-only transaction with strong concurrency.
table str
Required. The name of the table in the database to be read.
index str
If non-empty, the name of an index on table][google.spanner.v1.ReadRequest.table]. This index is used instead of the table primary key when interpreting key_set][google.spanner.v1.ReadRequest.key_set] and sorting result rows. See key_set][google.spanner.v1.ReadRequest.key_set] for further information.
columns Sequence[str]
Required. The columns of table][google.spanner.v1.ReadRequest.table] to be returned for each row matching this request.
key_set google.cloud.spanner_v1.types.KeySet
Required. key_set identifies the rows to be yielded. key_set names the primary keys of the rows in table][google.spanner.v1.ReadRequest.table] to be yielded, unless index][google.spanner.v1.ReadRequest.index] is present. If index][google.spanner.v1.ReadRequest.index] is present, then key_set][google.spanner.v1.ReadRequest.key_set] instead names index keys in index][google.spanner.v1.ReadRequest.index]. If the partition_token][google.spanner.v1.ReadRequest.partition_token] field is empty, rows are yielded in table primary key order (if index][google.spanner.v1.ReadRequest.index] is empty) or index key order (if index][google.spanner.v1.ReadRequest.index] is non-empty). If the partition_token][google.spanner.v1.ReadRequest.partition_token] field is not empty, rows will be yielded in an unspecified order. It is not an error for the key_set to name rows that do not exist in the database. Read yields nothing for nonexistent rows.
limit int
If greater than zero, only the first limit rows are yielded. If limit is zero, the default is no limit. A limit cannot be specified if partition_token is set.
resume_token bytes
If this request is resuming a previously interrupted read, resume_token should be copied from the last PartialResultSet][google.spanner.v1.PartialResultSet] yielded before the interruption. Doing this enables the new read to resume where the last read left off. The rest of the request parameters must exactly match the request that yielded this token.
partition_token bytes
If present, results will be restricted to the specified partition previously created using PartitionRead(). There must be an exact match for the values of fields common to this message and the PartitionReadRequest message used to create this partition_token.