DynamoDB Query with sort key and partition key - amazon-web-services

I am using JS SDK with DynamoDB to fetch data.
I am able to fetch data from my table using simple query with partition key and sort key.
My sort key sk has records -
Year#Batch#Rate
If I pass var sk = "2006#CSE#90"; it returns all of records matching this,
Requirement - How can I get all products with year 2006 , Batch CSE AND Rate =>90
readItem_pbro(){
console.log("inside pbro");
var table2 = "pbro";
var pk = "1";
var sk = "2006#CSE#90";
var params2 = {
TableName: table2,
Key:{
"pk": pk,
"sk": sk
}
};
Edit 1 :: Created a different column for score/rate as score. It is numeric.
Now my query in JS is -
but I am getting error - ValidationException: The provided key element does not match the schema
readItem_score_filter(){
console.log("inside pbro");
var table2 = "pbro";
var pk = "1"; // string
var sk = "2006#CSE"; // string
var score = 90; //number
var params2 = {
TableName: table2,
Key:{
"pk": pk,
"sk": sk,
FilterExpression:'score >=:score',
}
};
what is wrong in my FilterExpression.
Edit 2 :: Added Key condition Expression but issue still remains the same
Error: ValidationException: The provided key element does not match the schema
Here is my complete function now:
readItem_score_filter(){
console.log("inside pbro");
var table2 = "pbro";
var pk = "1"; //string
var sk = "2006#CSE"; // string
var score = 90; //number
var params2 = {
TableName: table2,
Key:{
"pk": pk,
"sk": sk,
"score": score,
KeyConditionExpression: 'pk = :pk AND sk=:sk',
FilterExpression: "score >=:score",
}
};
this.user.docClient.get(params2, function(err, data) {
if (err) {
console.log(err);
} else {
console.log(data);
}
});
}
Screenshot of table attached incase you need to see::

If "2006#CSE#90" this is the value of sort key column then you cant do anything at Dynamodb level..
comparings like this can be done through regular expressions but DynamoDB doesn't support Regular Expressions.
you simply need to get results and then seperate these values and compare ..
Updated :- use different column for score.
And use Filter Expression to get records having rate more than 90.
I dont know python , but still am trying here
var params2 = {
TableName: "pbro",
KeyConditionExpression: "pk = :pk AND sk =:sk",
FilterExpression: "score >= :score"
};

Related

get row by partition key on aws dynamodb

I'm trying to return a a row with id (partition key)
var db = new AWS.DynamoDB.DocumentClient();
const id = "123";
var queryParams = {
TableName: "students",
IndexName: "id",
KeyConditionExpression: "id = :id",
ExpressionAttributeValues: {
":id": id,
},
};
const query = db.query(queryParams).promise();
but is throwing this error:
ValidationException: 1 validation error detected: Value 'id' at 'indexName' failed to satisfy constraint: Member must have length greater than or equal to 3
isn't partition key enough to get a record? I'm confused partition key is not the same as index name?
I also tried with
var db = new AWS.DynamoDB.DocumentClient();
var queryParams = {
TableName: "students",
Key: {
id: "123",
},
};
const query = db.get(queryParams).promise();
and it doesn't return anything
You don't actually have an index named id. You don't need to provide an index when querying on the partition key. Simply remove this line:
IndexName: "id",
Also, note that both table and index names must be 3-255 characters in length (inclusive), which explains the error message that you see.
The following code (both query and get) works fine for me:
const AWS = require('aws-sdk');
AWS.config.update({ region: 'us-east-1' });
const db = new AWS.DynamoDB.DocumentClient();
const ID = "123";
const TABLE_NAME = "students";
const getParams = {
TableName: TABLE_NAME,
Key: {
id: ID,
},
};
const queryParams = {
TableName: TABLE_NAME,
KeyConditionExpression: "id = :id",
ExpressionAttributeValues: {
":id": ID,
},
};
(async () => {
const rc1 = await db.get(getParams).promise();
console.log('get rc:', rc1);
const rc2 = await db.query(queryParams).promise();
console.log('query rc:', rc2);
})();

Amazon Lex and DynamodDB - can't update existing item

I'm trying to get a specific item from a table.
My DynamoDB table name is table and I have:
Name PK | Number<br/>
S: Juan | S: #####
When I try to run in Lambda I don't get any Item when it really exist one with that name... any idea why it's like that?
AWS = require("aws-sdk"),
DDB = new AWS.DynamoDB({
region: "REGION",
}),
lookup_name_str = name //From Intent variable,
params = {
TableName: "table",
KeyConditionExpression: "name = :v1",
ExpressionAttributeValues: {
":v1":{
"S": lookup_name_str
}
},
FilterExpression: 'contains(nomColaborador,:v1)',
ProjectionExpression: "Number"
};
console.log(params);
var docClient = new AWS.DynamoDB.DocumentClient();
docClient.scan(params, function(err, data){
if(err){
throw err;
}
if(data.Items && data.Items[0] && data.Items[0].Number){
console.log("There is a Name with that number");
console.log(data.Items[0]);
my_response.statusCode = 200;
my_response.body = {
"sessionAttributes": {
"extension_str": data.Items[0].Number.S,
"nomColaborador": event.currentIntent.slots.Name
},
"dialogAction":{
"type": "Close",
"fulfillmentState": "Fulfilled",
"message": {
"contentType": "PlainText",
"content": data.Items[0].Number.S
}
}
};
The main problem here is that you are doing a scan. KeyConditionExpression isn't a parameter of a scan request. If you are requesting a single item by key you want to use getItem. If you need to query data by partition key and an optional sort key you should use query.
With that all said, when you do a scan, or put a filter on a query, you really need to be sure to page through the data. You will often find that you'll get a response with no data, but a paging key to make another call.

AWS DynamoDB filterexpression having multiple IN conditions clause with QueryRequest

When we using multiple IN conditions clause with QueryRequest, it only data which matches with the first item provided in IN condition.
I have Json format has
{
[
{
CID:1,
PId:1,
},
{
CID:2,
PID:2,
}
],
Age:30,
STATE:[
"AP", "TS"
],
Brands:[
"SAMSUNG","NOKIA","LG"
]
}
var filterExpression = " ((#CID= :CID1 and #PID = :PID1) or (#CID = :CID2 and #PID = :PID2) and #State in ( :state1, :state2) and #Brands in ( :brands1, :brands2)";
// Create Query request
QueryRequest request1 = new QueryRequest
{
TableName = "Table1",
IndexName = "Age-index",
KeyConditionExpression = "Age = :Age",
FilterExpression = filterExpression,
ExpressionAttributeNames = expressionAttributeNames,
ExpressionAttributeValues = expressionAttributeValues
};
var result = await dynamoClient.QueryAsync(request1);

Complex Queries in DynamoDB

I am working on an application that uses DynamoDB.
Is there a way where I can create a GSI with multiple attributes. My aim is to query the table with a query of following kind:
(attrA.val1 === someVal1 AND attrB.val2 === someVal2 AND attrC.val3 === someVal3)
OR (attrA.val4 === someVal4 AND attrB.val5 === someVal5 AND attrC.val6 === someVal6)
I am aware we can use Query when we have the Key Attribute and when Key Attribute is unknown we can use Scan operations. I am also aware of GSI if we need to query with non-key attributes. But I need some help in this scenario. Is there a way to model GSI to suit the above query.
I have the below item (i.e. data) on my Movies tables. The below query params works fine for me.
You can add the third attribute as present in the OP. It should work fine.
DynamoDB does support the complex condition on FilterExpression.
Query table based on some condition:-
var table = "Movies";
var year_val = 1991;
var title = "Movie with map attribute";
var params = {
TableName : table,
KeyConditionExpression : 'yearkey = :hkey and title = :rkey',
FilterExpression : '(records.K1 = :k1Val AND records.K2 = :k2Val) OR (records.K3 = :k3Val AND records.K4 = :k4Val)',
ExpressionAttributeValues : {
':hkey' : year_val,
':rkey' : title,
':k3Val' : 'V3',
':k4Val' : 'V4',
':k1Val' : 'V1',
':k2Val' : 'V2'
}
};
docClient.query(params, function(err, data) {
if (err) {
console.error("Unable to read item. Error JSON:", JSON.stringify(err,
null, 2));
} else {
console.log("GetItem succeeded:", JSON.stringify(data, null, 2));
}
});
My Data:-
Result:-
GetItem succeeded: {
"Items": [
{
"title": "Movie with map attribute",
"yearkey": 1991,
"records": {
"K3": "V3",
"K4": "V4",
"K1": "V1",
"K2": "V2"
}
}
],
"Count": 1,
"ScannedCount": 1
}

dynamodb in the browser getting started

I am little confused about retrieving data from dynamodb ... connecting is not an issue cause I am getting The provided key element does not match the schema
:the example provided from AWS
var table = new AWS.DynamoDB({params: {TableName: 'MY_TABLE'}});
var key = 'UNIQUE_KEY_ID';
var itemParams = {Item: {id: {S: key}, data: {S: 'data'}}};
table.getItem({Key: {id: {S: key}}}, function(err, data) {
console.log(data.Item); // print the item data
});
in my case the unique key is "time" and what I want to do is retrieve by key (not unique)
getItem only works on the primary key. From the docs: The GetItem operation returns a set of attributes for the item with the given primary key. See docs.
To solve this, create a Global Secondary Index that has "key" as HASH and "time" as RANGE. Then do a query operation using that index as IndexName:
var params = {
IndexName: 'your-new-GSI-index',
KeyConditionExpression: '#key = :key',
ExpressionAttributeNames: { '#key': 'key },
ExpressionAttributeValues: { ':key': { S: yourKeyVar } }
}
table.query(params, callback);
(did not test this code, but should work)