CODEWITHSUNDEEP
boto3dynamodb-queriesamazon-dynamodb-indexamazon-dynamodb
Justin
Justin

Reputation: 4843

DynamoDB gt() query on GSI

I am trying to get a gt() query working with a DynamoDB GSI

My Cloudformation is as follows -

Resources
  MyTable:
    Properties:
      AttributeDefinitions:
      - AttributeName: pk
        AttributeType: S
      - AttributeName: sk
        AttributeType: S
      - AttributeName: my_datetime_string
        AttributeType: S
      BillingMode: PAY_PER_REQUEST
      GlobalSecondaryIndexes:
      - IndexName: my_datetime_string-index
        KeySchema:
        - AttributeName: my_datetime_string
          KeyType: HASH
        Projection:
          ProjectionType: ALL
      KeySchema:
      - AttributeName: pk
        KeyType: HASH
      - AttributeName: sk
        KeyType: RANGE
      TableName:
        Fn::Sub: my-table-${AWS::StackName}-${AWS::Region}
    Type: AWS::DynamoDB::Table

My query code is as follows (python) -

tablename="whatever"
import boto3
table=boto3.resource("dynamodb").Table(tablename)
from datetime import datetime
timestamp="%s 00:00:00" % datetime.today().strftime("%Y-%m-%d")
from boto3.dynamodb.conditions import Key
expr=Key("my_datetime_string").gt(timestamp)
print (table.query(IndexName="my_datetime_string-index",        
                   KeyConditionExpression=expr))

I have some data in the table and have can see that it has a String type (my_datetime_string) -

{'Item': {'my_datetime_string': '2022-01-27 14:30:00', 'sk': 'HEAD', 'pk': 'EVENT#1293000'}, 'ResponseMetadata': {'RequestId': 'XXX', 'HTTPStatusCode': 200, 'HTTPHeaders': {'server': 'Server', 'date': 'Tue, 08 Feb 2022 10:54:15 GMT', 'content-type': 'application/x-amz-json-1.0', 'content-length': '522', 'connection': 'keep-alive', 'x-amzn-requestid': 'XXX', 'x-amz-crc32': '2080419831'}, 'RetryAttempts': 0}}

But all I get from the query is -

An error occurred (ValidationException) when calling the Query operation: Query key condition not supported

What am I missing here ? Surely GSI indexes support gt() queries for String types ? (or maybe not ??)

Upvotes: 0

Views: 681

Answers (1)

fedonev
fedonev

Reputation: 25649

my_datetime_string is your index's Partition Key (= Hash Key). A Query must provide one-and-only-one Partition Key value. This means that eq is a valid operator in Partition Key conditions, but gt is not.

If your table/index has a compound primary key, a query can apply a gt operation to the Sort Key (= Range Key) condition, which will return a range of values.

Upvotes: 2

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