I have a query in DynamoDB to retrieve items that match a given condition in my partition
response = {'input': table.query(KeyConditionExpression=Key('project').eq(project_data)
& Key('name').eq(name), IndexName='my-index').get('Items') }
I would like to retrieve data when the value of Project exists in a list, it is, something like setting the condition to Key('project').in(project_data)
How can i do this in dynamodb?
Thanks
Related
Consider Below is my sample json.
{
"servletname": "cofaxEmail",
"servlet-class": "org.cofax.cds.EmailServlet",
"init-param": {
"mailHost": "mail1",
"mailHostOverride": "mail2"
}
i have chosen "servletname" as my primary key as i will receive it in every request plus few 1000 server names are there it could be the best PK.
My Question is, to make the partition key work for me.
Do i have to specify the partition key option seperately like below
ItemResponse<ServerDto> ServerDtoResponse = await this.container.ReadItemAsync<ServerDto>(bocServerDto.mailHost, new PartitionKey(bocServerDto.servletname));
or
Including the partition key in the select query itself , without adding seperate new PartitionKey(), like
select * from r where r.servletname='cofaxEmail' and r.mailHost='mail1';
Crux of the question is: By passing partitionKey object in where condition of select query is it enough to utilize the partition key feature?
Thanks
For any crud operation you would pass in the value for the partition key. For example, on a point read.
ItemResponse<ServerDto> ServerDtoResponse = await this.container.ReadItemAsync<ServerDto>(bocServerDto.mailHost, new PartitionKey("cofaxEmail"));
For a query, you can either pass it in the queryRequest options or use it in the query as the first filter predicate. Here is an example of using the queryRequest options.
thanks.
I have a dynamo DB table (id(pk),name(sk),email,date,itemId(number))
and GSI on (itemId pk, date(sk)
trying to query for an array of itemIds [1,2,3,4] but getting error using the IN statement in KeyExperssionValue when doing
aws.DocClient.query
const IdsArrat = [1,2,3,4,5];
const query: {
IndexName: 'accountId-createdAt-index',
KeyConditionExpression: 'itemId IN (:a1,:a2,:a3)',
ExpressionAttributeValues: {
{
':a1':1,
':a2':2,
.......
}
},
ScanIndexForward: false,
},
getting error using the IN statement in.
This it possible to query for multiple values on GSI in dynamoDb ?
You're trying to query for multiple different partition key's in a GSI. This can only be done by doing multiple individual queries (3 in the example). It's also possible with a GSI that multiple values would get returned for a single Partition key lookup, so it's better to query the partition key "itemId" individually.
See the following for reference:
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.html#DDB-Query-request-KeyConditionExpression
It's not possible to have a IN and join multiple values in a query , but it's possible to use BatchGetItem to request multiple queries that are solved in parallel . This is actually very close to the IN solution you want.
The result will be a list of the elements in the table.
There are limits in the number of queries in the size of the result set < 16 MB and the number of queries < 100.
Please check this document for details :
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_BatchGetItem.html
refering to this answer https://stackoverflow.com/a/70494101/7706503, you could try partiQL to construct similar statement for querying gsi table with multiple key,
select * from table."gsi_index_name" where partition_key in [key1,key2]
then you could send the statement with low level api in one shot, for example, in dotnet, it's called ExecuteStatementAsync
I am using boto3 to create a simple DynamoDB query as follows:
response = table.query(
KeyConditionExpression=Key('course-lesson-id-part').eq(1)
)
This query works and return the single item just like it should.
course-lesson-id-part is my primary partition key and is numeric; I have two items in my table:
course-lesson-id-part: 1
course-lesson-id-part: 2
Ideally, and according to this reference, I should be able to use the following to query all items with course-lesson-id-part > 0:
response = table.query(
KeyConditionExpression=Key('course-lesson-id-part').gt(0)
)
None of the other DB Query conditions seem to be working other than .eq, which does me no good here.
Anyone have any ideas?
Only eq is supported for partition keys.
You must specify the partition key name and value as an equality condition.
Source: Working with Queries
I have a requirement to query the dynamoDB and get all the records which matches a certain criteria. The requirement is, I have table say parent_child_table, which has parent_id and child_id as two columns, now i need to query the table with a particular input id and fetch all the records. for Example
now if I query the db with id 67899, the I should get both two records i.e 12345 and 67899.
I was trying to use below methods :
GetItemRequest itemRequest=new GetItemRequest().withTableName("PARENT_CHILD_TABLE").withKey(partitionKey.entrySet().iterator().next(), sortKey.entrySet().iterator().next());
but am not getting OR operator.
DynamoDB doesn't work like that...
GetItemRequest() can only return a single record.
Query() can return multiple records, but only if you are using a composite primary key (partition key + sort key) and you can only query within a single partition...so all the records to be returned must have the same partition key.
Scan() can return multiple records from any partition, but it does so by always scanning the entire table. Regular use of scan is a bad idea.
Without knowing more it's hard to provide guidance, but consider a schema like so:
partition key sort key
12345 12345
12345 12345#67899
12345 12345#67899#97765
Possibly adding some sort of level indicator in the sort key or just as an attribute.
I want to update all records matching a query in Fire/DataStore, how do I do it?
The SQL equivalent will look like
UPDATE transactions SET category = X WHERE category = Y
Seems like to do this I will have to query all records matching category = Y then for each do a set()?
Firestore (like most NoSQL databases) does not support sending update queries directly to the database.
To update documents matching a query, you will indeed first need to execute that query and then update each document.