Hi im trying to append an item to a dynamoDB array.
exports.handler = (event,context,callback)=>{
let params = {
Key:{
"userName":event.userName,
},
UpdateExpression:"set #FutureTrips = list_append(if_not_exists(#FutureTrips,empty_list),country)",
ExpressionAttributeNames:{
"#FutureTrips" : "FutureTrips"
},
ExpressionAttributeValues: {
':country':["Japan"],
":empty_list":[]
},
TableName:"Users"
};
dynamoDB.updateItem(params,function(err,data){
if(err){
console.log(err);
callback(null,err);
}
else{
callback(null,data);
}
});
};
it returns me "message": "Unexpected key '0' found in params.ExpressionAttributeValues[':country']",
im trying to append an item to an array called FutureTrips
thanks for the help
Based on the code you share, currently the UpdateExpression is not referring to the specified ExpressionAttributeValues.
UpdateExpression:"set #FutureTrips = list_append(if_not_exists(#FutureTrips,empty_list),country)"
Correct UpdateExpression should be;
UpdateExpression: "set #FutureTrips = list_append(if_not_exists(#FutureTrips, :empty_list), :country)"
Related
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'm playing with the New Data API for Amazon Aurora Serverless
Is it possible to get the table column names in the response?
If for example I run the following query in a user table with the columns id, first_name, last_name, email, phone:
const sqlStatement = `
SELECT *
FROM user
WHERE id = :id
`;
const params = {
secretArn: <mySecretArn>,
resourceArn: <myResourceArn>,
database: <myDatabase>,
sql: sqlStatement,
parameters: [
{
name: "id",
value: {
"stringValue": 1
}
}
]
};
let res = await this.RDS.executeStatement(params)
console.log(res);
I'm getting a response like this one, So I need to guess which column corresponds with each value:
{
"numberOfRecordsUpdated": 0,
"records": [
[
{
"longValue": 1
},
{
"stringValue": "Nicolas"
},
{
"stringValue": "Perez"
},
{
"stringValue": "example#example.com"
},
{
"isNull": true
}
]
]
}
I would like to have a response like this one:
{
id: 1,
first_name: "Nicolas",
last_name: "Perez",
email: "example#example.com",
phone: null
}
update1
I have found an npm module that wrap Aurora Serverless Data API and simplify the development
We decided to take the current approach because we were trying to cut down on the response size and including column information with each record was redundant.
You can explicitly choose to include column metadata in the result. See the parameter: "includeResultMetadata".
https://docs.aws.amazon.com/rdsdataservice/latest/APIReference/API_ExecuteStatement.html#API_ExecuteStatement_RequestSyntax
Agree with the consensus here that there should be an out of the box way to do this from the data service API. Because there is not, here's a JavaScript function that will parse the response.
const parseDataServiceResponse = res => {
let columns = res.columnMetadata.map(c => c.name);
let data = res.records.map(r => {
let obj = {};
r.map((v, i) => {
obj[columns[i]] = Object.values(v)[0]
});
return obj
})
return data
}
I understand the pain but it looks like this is reasonable based on the fact that select statement can join multiple tables and duplicated column names may exist.
Similar to the answer above from #C.Slack but I used a combination of map and reduce to parse response from Aurora Postgres.
// declarative column names in array
const columns = ['a.id', 'u.id', 'u.username', 'g.id', 'g.name'];
// execute sql statement
const params = {
database: AWS_PROVIDER_STAGE,
resourceArn: AWS_DATABASE_CLUSTER,
secretArn: AWS_SECRET_STORE_ARN,
// includeResultMetadata: true,
sql: `
SELECT ${columns.join()} FROM accounts a
FULL OUTER JOIN users u ON u.id = a.user_id
FULL OUTER JOIN groups g ON g.id = a.group_id
WHERE u.username=:username;
`,
parameters: [
{
name: 'username',
value: {
stringValue: 'rick.cha',
},
},
],
};
const rds = new AWS.RDSDataService();
const response = await rds.executeStatement(params).promise();
// parse response into json array
const data = response.records.map((record) => {
return record.reduce((prev, val, index) => {
return { ...prev, [columns[index]]: Object.values(val)[0] };
}, {});
});
Hope this code snippet helps someone.
And here is the response
[
{
'a.id': '8bfc547c-3c42-4203-aa2a-d0ee35996e60',
'u.id': '01129aaf-736a-4e86-93a9-0ab3e08b3d11',
'u.username': 'rick.cha',
'g.id': 'ff6ebd78-a1cf-452c-91e0-ed5d0aaaa624',
'g.name': 'valentree',
},
{
'a.id': '983f2919-1b52-4544-9f58-c3de61925647',
'u.id': '01129aaf-736a-4e86-93a9-0ab3e08b3d11',
'u.username': 'rick.cha',
'g.id': '2f1858b4-1468-447f-ba94-330de76de5d1',
'g.name': 'ensightful',
},
]
Similar to the other answers, but if you are using Python/Boto3:
def parse_data_service_response(res):
columns = [column['name'] for column in res['columnMetadata']]
parsed_records = []
for record in res['records']:
parsed_record = {}
for i, cell in enumerate(record):
key = columns[i]
value = list(cell.values())[0]
parsed_record[key] = value
parsed_records.append(parsed_record)
return parsed_records
I've added to the great answer already provided by C. Slack to deal with AWS handling empty nullable character fields by giving the response { "isNull": true } in the JSON.
Here's my function to handle this by returning an empty string value - this is what I would expect anyway.
const parseRDSdata = (input) => {
let columns = input.columnMetadata.map(c => { return { name: c.name, typeName: c.typeName}; });
let parsedData = input.records.map(row => {
let response = {};
row.map((v, i) => {
//test the typeName in the column metadata, and also the keyName in the values - we need to cater for a return value of { "isNull": true } - pflangan
if ((columns[i].typeName == 'VARCHAR' || columns[i].typeName == 'CHAR') && Object.keys(v)[0] == 'isNull' && Object.values(v)[0] == true)
response[columns[i].name] = '';
else
response[columns[i].name] = Object.values(v)[0];
}
);
return response;
}
);
return parsedData;
}
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);
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
}