I need another set of eyes on this. For the life of me I see no issues with this parameter set, used for Dynamo DocumentClient, update method - (here: https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB/DocumentClient.html#update-property ).
{
TableName: "mygame-dev",
Key: { pk: "09d017aa-cbf7-42ce-be6a-a94ecb58f9a7", sk: "GAME" },
ExpressionAttributeNames: { "#GAMELASTUPDATED": "gameLastUpdated", "#GAMETITLE": "gameTitle" },
ExpressionAttributeValues: { ":gamelastupdated": 1556376010704, ":gametitle": "test title 1" },
UpdateExpression: "SET #GAMELASTUPDATED = :gamelastupdated, #GAMETITLE = :gametitle",
ReturnValues: "ALL_NEW"
};
Error:
ValidationException: ExpressionAttributeNames can only be specified
when using expressions
Any thoughts?
Disregard, this was a copy and paste issue... I was using "query" not "update"
Was:
const updateGameResult = await ddbCall("query", params);
Should have been:
const updateGameResult = await ddbCall("update", params);
Related
I am able to SET values for reserved keywords but not able to remove certain keywords in dynamodb.
My expression is below. Not able to remove data if I give like this. But able to remove size though.
Invalid UpdateExpression: Attribute name is a reserved keyword; reserved keyword:data
{
ConditionExpression: "#id = :id",
ExpressionAttributeNames: {
"#id": "id",
“#name": “name",
},
ExpressionAttributeValues: {
":id": “1234566",
“:name": “John",
},
Key: {
id: "1234566",
},
ReturnValues: "ALL_NEW",
TableName: “table_name",
UpdateExpression: "SET #name = :name REMOVE size, data",
}
Modified to include data in expression attribute names as below. Still throws error.
{
ConditionExpression: "#id = :id",
ExpressionAttributeNames: {
"#id": "id",
“#name": “name",
“#size": “size",
“#data": “data",
},
ExpressionAttributeValues: {
":id": “1234566",
“:name": “John",
“:size": undefined,
“:data": undefined,
},
Key: {
id: "1234566",
},
ReturnValues: "ALL_NEW",
TableName: "table_name",
UpdateExpression: "SET #name = :name, #size = :size, #data =
:data REMOVE size, data”,
}
Remove size and data from ExpressionAttributeValues and from SET UpdateExpression. Add #size and #data to REMOVE on UpdateExpression instead of size and data.
{
ConditionExpression: "#id = :id",
ExpressionAttributeNames: {
"#id": "id",
“#name": “name",
“#size": “size",
“#data": “data",
},
ExpressionAttributeValues: {
":id": “1234566",
“:name": “John"
},
Key: {
id: "1234566",
},
ReturnValues: "ALL_NEW",
TableName: "table_name",
UpdateExpression: "SET #name = :name, REMOVE #size, #data”,
}
Reserved words in DynamoDB
to do that dynamically you need only to provide a json object with this function
it's create dynamically
-ExpressionAttributeNames
-ExpressionAttributeValues
-UpdateExpression
also skip reserved keyword for dynamodb
def generate_update_att(body):
"""
#############input
body={
'newval':newData['newval'],
'lastname':newData['lastname'],
'name':newData['name']
}
#################output
-ExpressionAttributeNames
-ExpressionAttributeValues
-UpdateExpression
"""
UpdateExpression = ["set "]
ExpressionAttributeValues = dict()
ExpressionAttributeNames=dict()
for key, val in body.items():
UpdateExpression.append(f" #{key} = :{key},")
ExpressionAttributeValues[f":{key}"] = val
ExpressionAttributeNames[f"#{key}"] = key
return "".join(UpdateExpression)[:-1], ExpressionAttributeValues,ExpressionAttributeNames
function Call
my_data={
'newval':newData['newval'],
'lastname':newData['lastname'],
'name':newData['name']
}
a, v,z = generate_update_att(my_data)
my_table.update_item(
Key={'id':my_id},
UpdateExpression=my_UpdateExpression,
ExpressionAttributeValues=dict(my_ExpressionAttributeValues),
ExpressionAttributeNames=dict(my_ExpressionAttributeNames)
)
I need to execute query like this:
select * from table where sampling_date like "2020-05-%"
To do this, I'm calling for
db.query({
TableName: "Tubes",
Select: "ALL_ATTRIBUTES",
IndexName: "sampling_date_idx",
KeyConditionExpression: " sampling_date > :sampling_date ",
ExpressionAttributeValues:{ ':sampling_date': {'S': '2020-05-'}}
}, function(error: AWSError, data: QueryOutput){
console.log(error, data);
})
And I get this error message:
{"errorType":"Error","errorMessage":"{\"message\":\"Query key condition not supported\",\"code\":\"ValidationException\",
My table:
this.tubes = new dynamodb.Table(this, "tubes", {
tableName: "Tubes",
billingMode: dynamodb.BillingMode.PAY_PER_REQUEST,
partitionKey: {
name: "id",
type: dynamodb.AttributeType.STRING
},
pointInTimeRecovery: true,
removalPolicy: cdk.RemovalPolicy.RETAIN
});
this.tubes.addGlobalSecondaryIndex({
indexName: "sampling_date_idx",
sortKey: {
name: 'sampling_date_srt',
type: AttributeType.STRING
},
partitionKey: {
name: "sampling_date",
type: AttributeType.STRING,
},
})
I think there are two issues in your current code -
In KeyConditionExpression, there must be an equality condition on a single partition key value. In your case, it must include "sampling_date = :sampling_date".
Please read "KeyConditionExpression" section in -
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.html
In short, you only can perform equality test against partition key.
I am not sure which language you use. I suspect your syntax for ExpressionAttributeValues is not correct.
The syntax given in AWS doc is -
"ExpressionAttributeValues": {
"string" : {
"B": blob,
"BOOL": boolean,
"BS": [ blob ],
"L": [
"AttributeValue"
],
"M": {
"string" : "AttributeValue"
},
"N": "string",
"NS": [ "string" ],
"NULL": boolean,
"S": "string",
"SS": [ "string" ]
}
}
In your case, it may be something like -
"ExpressionAttributeValues": {
":sampling_date": {"S": "2020-05-01"}
}
My experience is in C#, it may be something like -
ExpressionAttributeValues = new Dictionary<string, AttributeValue>()
{
{ ":sampling_date", new AttributeValue{S = "2005-05-01"} }
}
To solve your problem, you may need to use another attribute as the index's partition key. sampling_date only can be used as sort key.
sampling_date is the partition key for your GSI sampling_date_idx.
DynamoDB documentation says that in key condition expressions:
You must specify the partition key name and value as an equality condition.
Source: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html#Query.KeyConditionExpressions
So sampling_date can only be used with the "equal to" comparison operator. None of the other operators like less than, greater than, between, contains, begins with, etc. can be used with sampling_date.
However, these operators can be used with a sort key!
So if you can redesign your table and/or indexes such that sampling_date becomes a sort key of some index, you can use begins_with on it.
Here's a suggestion:
Create a GSI with partition key = sampling_year & sort key = sampling_date.
Then if your table has the following items:
{
"id": "id1",
"sampling_year": 2020,
"sampling_date": "2020-04-01"
}
{
"id": "id2",
"sampling_year": 2020,
"sampling_date": "2020-05-01"
}
{
"id": "id3",
"sampling_year": 2020,
"sampling_date": "2020-06-01"
}
And you use the following Node.js code:
let AWS = require("aws-sdk")
let dc = new AWS.DynamoDB.DocumentClient()
dc.query({
TableName: "Tubes",
IndexName: "sampling_year-sampling_date-index",
KeyConditions: {
"sampling_year": {
ComparisonOperator: "EQ",
AttributeValueList: [2020]
},
"sampling_date": {
ComparisonOperator: "BEGINS_WITH",
AttributeValueList: ["2020-05-"]
}
}
}
You'll get your desired output:
{
"id": "id2",
"sampling_year": 2020,
"sampling_date": "2020-05-01"
}
Try
KeyConditionExpression: `begins_with(sampling_date, :sampling_date)`
See available condition expressions here...
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Condition.html
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.
Say I want to add a record like below:
{
id:876876,
username:example,
email:xxxxxx#xxx.com,
phone:xxxxxxx,
created_at:current_date,
updated_at:current_date
}
What I want is to check with the id if record exist created_date should not be modified only updated_date should have current_date.
Can we do this with put method without having to be making a get item call?
To create a new item or update an existing item with conditional expression. Prefer to use updateItem rather than putItem.
If the Hash key (Primary key) doesn't exist both putItem and updateItem create a new record. If the record already exist, putItem will completely override the existing row but updateItem only updates the attributes passed in UpdateExpression not a whole record.
In your case, use if_not_exists() function to check whether the created_at field already exists or not. If exists created_at will not be overridden.
Update expression: "SET #email = :email, #created_at = if_not_exists(#created_at, :created_at), #updated_at = :updated_at"
Sample snippet
var params = {
ExpressionAttributeNames: {
"#email": "email",
"#created_at": "created_at",
"#updated_at": "updated_at"
},
ExpressionAttributeValues: {
":email": {
S: "test2#grr.la"
},
":created_at": {
S: date.toISOString()
},
":updated_at": {
S: date.toISOString()
}
},
Key: {
"id": {
S: "T1"
}
},
ReturnValues: "ALL_NEW",
TableName: "stack",
UpdateExpression: "SET #email = :email, #created_at = if_not_exists(#created_at, :created_at), #updated_at = :updated_at"
};
ddb.updateItem(params, function(err, data) {
if (err) console.log(err, err.stack); // an error occurred
else console.log(data);
})
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)