Struct TransactConditionCheckRequest 

pub struct TransactConditionCheckRequest<TD: TableDefinition, T = ()> { /* private fields */ }

Builder for a ConditionCheck operation inside a DynamoDB transaction.

A condition check does not mutate any item — it only asserts that a condition holds. If the condition fails, the entire transaction is cancelled. Use this to enforce invariants on items that are not otherwise being modified in the same transaction.

Constructed via DynamoDBItemTransactOp::transact_condition or DynamoDBItemTransactOp::transact_condition_by_id.

Call .build() to produce a TransactWriteItem that can be passed to the SDK’s transact_write_items() builder.

Examples

Verify the user is an admin before toggling maintenance mode:

use dynamodb_facade::{DynamoDBItemOp, DynamoDBItemTransactOp, Condition, KeyId, Update};

let user = sample_user();

client
    .transact_write_items()
    .transact_items(
        user.transact_condition(
            User::exists() & Condition::eq("role", "admin"),
        )
        .build(),
    )
    .transact_items(
        PlatformConfig::transact_update_by_id(
            KeyId::NONE,
            Update::set("maintenance_mode", true),
        )
        .exists()
        .build(),
    )
    .send()
    .await?;

Implementations

impl<TD: TableDefinition, T> TransactConditionCheckRequest<TD, T>

pub fn new(key: Key<TD>, condition: Condition<'_>) -> Self

Creates a new TransactConditionCheckRequest from a raw Key and a Condition.

Prefer DynamoDBItemTransactOp::transact_condition or DynamoDBItemTransactOp::transact_condition_by_id for typed construction.

pub fn into_inner(self) -> ConditionCheckBuilder

Consumes the builder and returns the underlying SDK ConditionCheckBuilder.

Use this escape hatch when you need to set options not exposed by this facade.

pub fn build(self) -> TransactWriteItem

Finalizes the builder and returns a TransactWriteItem.

The returned value can be passed directly to the SDK’s transact_write_items().transact_items(...) call.

Examples

use dynamodb_facade::{DynamoDBItemOp, DynamoDBItemTransactOp, Condition, KeyId, Update};

let user = sample_user();

// Verify the user is an admin before toggling maintenance mode
client
    .transact_write_items()
    .transact_items(
        user.transact_condition(
            User::exists() & Condition::eq("role", "admin"),
        )
        .build(),
    )
    .transact_items(
        PlatformConfig::transact_update_by_id(
            KeyId::NONE,
            Update::set("maintenance_mode", true),
        )
        .exists()
        .build(),
    )
    .send()
    .await?;