Method: googleapis.spanner.v1.projects.instances.databases.sessions.read

Reads rows from the database using key lookups and scans, as a simple key/value style alternative to ExecuteSql. This method can't be used to return a result set larger than 10 MiB; if the read matches more data than that, the read fails with a FAILED_PRECONDITION error. Reads inside read-write transactions might return ABORTED. If this occurs, the application should restart the transaction from the beginning. See Transaction for more details. Larger result sets can be yielded in streaming fashion by calling StreamingRead instead.

For more information about retries and long-running operations, see Understand connectors.

Arguments

Parameters
session

string

Required. The session in which the read should be performed.
body

object (ReadRequest)

Required.

Raised exceptions

Exceptions
ConnectionError In case of a network problem (such as DNS failure or refused connection).
HttpError If the response status is >= 400 (excluding 429 and 503).
TimeoutError If a long-running operation takes longer to finish than the specified timeout limit.
TypeError If an operation or function receives an argument of the wrong type.
ValueError If an operation or function receives an argument of the right type but an inappropriate value. For example, a negative timeout.

Response

If successful, the response contains an instance of ResultSet.

Subworkflow snippet

Some fields might be optional or required. To identify required fields, refer to the API documentation.

YAML

- read:
    call: googleapis.spanner.v1.projects.instances.databases.sessions.read
    args:
        session: ...
        body:
            columns: ...
            dataBoostEnabled: ...
            directedReadOptions:
                excludeReplicas:
                    replicaSelections: ...
                includeReplicas:
                    autoFailoverDisabled: ...
                    replicaSelections: ...
            index: ...
            keySet:
                all: ...
                keys: ...
                ranges: ...
            limit: ...
            lockHint: ...
            orderBy: ...
            partitionToken: ...
            requestOptions:
                priority: ...
                requestTag: ...
                transactionTag: ...
            resumeToken: ...
            table: ...
            transaction:
                begin:
                    excludeTxnFromChangeStreams: ...
                    isolationLevel: ...
                    partitionedDml: ...
                    readOnly:
                        exactStaleness: ...
                        maxStaleness: ...
                        minReadTimestamp: ...
                        readTimestamp: ...
                        returnReadTimestamp: ...
                        strong: ...
                    readWrite:
                        multiplexedSessionPreviousTransactionId: ...
                        readLockMode: ...
                id: ...
                singleUse: ...
    result: readResult

JSON

[
  {
    "read": {
      "call": "googleapis.spanner.v1.projects.instances.databases.sessions.read",
      "args": {
        "session": "...",
        "body": {
          "columns": "...",
          "dataBoostEnabled": "...",
          "directedReadOptions": {
            "excludeReplicas": {
              "replicaSelections": "..."
            },
            "includeReplicas": {
              "autoFailoverDisabled": "...",
              "replicaSelections": "..."
            }
          },
          "index": "...",
          "keySet": {
            "all": "...",
            "keys": "...",
            "ranges": "..."
          },
          "limit": "...",
          "lockHint": "...",
          "orderBy": "...",
          "partitionToken": "...",
          "requestOptions": {
            "priority": "...",
            "requestTag": "...",
            "transactionTag": "..."
          },
          "resumeToken": "...",
          "table": "...",
          "transaction": {
            "begin": {
              "excludeTxnFromChangeStreams": "...",
              "isolationLevel": "...",
              "partitionedDml": "...",
              "readOnly": {
                "exactStaleness": "...",
                "maxStaleness": "...",
                "minReadTimestamp": "...",
                "readTimestamp": "...",
                "returnReadTimestamp": "...",
                "strong": "..."
              },
              "readWrite": {
                "multiplexedSessionPreviousTransactionId": "...",
                "readLockMode": "..."
              }
            },
            "id": "...",
            "singleUse": "..."
          }
        }
      },
      "result": "readResult"
    }
  }
]