Module serde_dynamo::aws_sdk_dynamodb_0_14

source ·
Available on crate feature aws-sdk-dynamodb+0_14 only.
Expand description

Support for aws-sdk-dynamodb version 0.14

Because aws-sdk-dynamodb has not yet reached version 1.0, a feature is required to enable support. Add the following to your dependencies.

[dependencies]
aws-config = "0.44"
aws-sdk-dynamodb = "0.14"
serde_dynamo = { version = "4", features = ["aws-sdk-dynamodb+0_14"] }

§Parsing items as strongly-typed data structures.

Items received from a aws-sdk-dynamodb call can be run through from_items.

#[derive(Serialize, Deserialize)]
pub struct User {
    id: String,
    name: String,
    age: u8,
};

// Get documents from DynamoDB
let result = client.scan().table_name("user").send().await?;

// And deserialize them as strongly-typed data structures
if let Some(items) = result.items().map(|slice| slice.to_vec()) {
    let users: Vec<User> = from_items(items)?;
    println!("Got {} users", users.len());
}

Alternatively, to deserialize one item at a time, from_item can be used.

#[derive(Serialize, Deserialize)]
pub struct User {
    id: String,
    name: String,
    age: u8,
};

// Get documents from DynamoDB
let result = client.scan().table_name("user").send().await?;

// And deserialize them as strongly-typed data structures
for item in result.items().map(|slice| slice.to_vec()).unwrap() {
    let user: User = from_item(item)?;
    println!("{} is {}", user.name, user.age);
}

§Creating items by serializing data structures

Writing an entire data structure to DynamoDB typically involves using to_item to serialize it.

#[derive(Serialize, Deserialize)]
pub struct User {
    id: String,
    name: String,
    age: u8,
};

// Create a user
let user = User {
    id: "fSsgVtal8TpP".to_string(),
    name: "Arthur Dent".to_string(),
    age: 42,
};

// Turn it into an item that aws-sdk-dynamodb understands
let item = to_item(user)?;

// And write it!
client.put_item().table_name("users").set_item(Some(item)).send().await?;

§Using to_attribute_value for more control

In some circumstances, building aws_sdk_dynamodb::model::AttributeValues directly is required.

For example, when generating a key to supply to get_item.

use serde_dynamo::to_attribute_value;

// Create the unique key of the record in DynamoDB in a way rusoto understands
let key = HashMap::from([
    (String::from("id"), to_attribute_value(&user.id)?),
]);

// And get the record
client.get_item().table_name("users").set_key(Some(key)).send().await?;

Or when generating attribute values in a query call.

use serde_dynamo::to_attribute_value;

// Declare all of the expression inputs for a query call
let expression_attribute_values = HashMap::from([
    (String::from(":user_type"), to_attribute_value(user_type)?),
    (String::from(":last_login"), to_attribute_value(yesterday)?),
]);

client.query()
    .table_name("users")
    .index_name("by_type_and_last_login")
    .key_condition_expression("user_type = :user_type AND last_login > :last_login")
    .set_expression_attribute_values(Some(expression_attribute_values))
    .send()
    .await?;

Functions§