const params = {
TableName: 'user_details',
KeyConditionExpression: '#user_id = :user_id and begins_with(#user_relation, :user_relation)',
ExpressionAttributeNames:{
"#user_id": "user_id",
"#user_relation": 'user_relation'
},
ExpressionAttributeValues: {
":user_id": "1234",
":user_relation": "followed-by"
}
}