即使密钥不存在,如何插入DynamoDb [英] How to insert to DynamoDb just if the key does not exist
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问题描述
我只想向DynamoDb添加一次id +一些值.如果该ID已经存在,则不应执行任何操作或更新
I want to add id + some values to a DynamoDb just once. If the id exists already it should do nothing or update
我可以和
search
if not found > insert
if found > do nothing or update (for now do nothing is fine)
但希望有更好的方法来做到这一点.ID应该是检查的关键.
But hopfully there is a better way to do it. The id should be the key to check for.
那是节点中的代码:
const dynamodbParams = {
TableName: process.env.DYNAMODB_TABLE_BLICKANALYTICS,
Item: {
id: userId,
createdAt: timestamp
},
};
dynamoDb.put(dynamodbParams).promise()
.then(data => {
console.log('saved: ', dynamodbParams);
})
.catch(err => {
console.error(err);
});
我在yml中使用它.不知道是否有在yml中设置的选项
I use this in yml. Don't know if there are options to set this up in yml
resources:
Resources:
DynamoDbTableExpenses:
Type: 'AWS::DynamoDB::Table'
DeletionPolicy: Retain
Properties:
AttributeDefinitions:
-
AttributeName: id
AttributeType: S
-
AttributeName: createdAt
AttributeType: N
KeySchema:
-
AttributeName: id
KeyType: HASH
-
AttributeName: createdAt
KeyType: RANGE
ProvisionedThroughput:
ReadCapacityUnits: 1
WriteCapacityUnits: 1
TableName: ${self:provider.environment.DYNAMODB_TABLE_BLICKANALYTICS}
推荐答案
您可以使用一个如果只想插入(如果不存在),则可以使用
If you only want to do insert if not exists, you can easily do that with PutItem:
const dynamodbParams = {
TableName: process.env.DYNAMODB_TABLE_BLICKANALYTICS,
Item: {
id: userId,
createdAt: timestamp
},
ConditionExpression: 'attribute_not_exists(id)'
};
dynamodb.putItem(params, function(err, data) {
if (err) {
console.log(err, err.stack);
} else {
console.log(data);
}
}
请注意,我尚未完全测试代码,因此请注释是否有任何错误,但应该可以.
Note I have not fully tested the code, so please comment if there's any error, but it should work.
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