Node.JS - Trying to delete certain items from a DynamoDB table - node.js

Question

I am trying to delete all records which have the attribute "code" from a DynamoDB table. Here my params:
var params = {
TableName: table,
Key:{
"email": "email",
},
ConditionExpression:"attribute_exists(code)",
};
This is the error:
{
"message": "The conditional request failed",
"code": "ConditionalCheckFailedException",
"time": "2021-11-12T09:01:04.205Z",
"requestId": "e1d74c46-86a0-4f14-8c62-186102f2aff3",
"statusCode": 400,
"retryable": false,
"retryDelay": 36.80819226584606
}
An example record looks like this:
email - first_name - last_name - hash - code - confirmed
e#icloud.com - Bob - Mann - $2b$10$5/x6BkCks6ndXSr/GRhLgOPk.ettTv3lYpglbZbGnM7FXPX5VRFCe - undefined - undefined

Answer 1

According to the documentation:
ConditionalCheckFailedException
Message: The conditional request failed.
You specified a condition that was evaluated to be false. For example, you might have tried to perform a conditional update on an item, but the actual value of the attribute did not match the expected value in the condition.
OK to retry? No
So the problem is with the ConditionExpression, the code attribute does not exist in some records or it exists with undefined value. try to change attribute_exists with attribute_type:
var params = {
TableName: table,
Key:{
"email": "email",
},
ConditionExpression:"attribute_type(code, S)",
};
The second parameter:
S — String
SS — String Set
N — Number
NS — Number Set
B — Binary
BS — Binary Set
BOOL — Boolean
NULL — Null
L — List
M — Map
read more on comparison and function on amazondynamodb.