Conditional Writes

All write operations (put, update, delete) support condition= (AND logic) and condition_or= (OR logic).

Condition Syntax

# Only create if not exists (idempotent put)
try:
    orders.put(
        user_id="usr_123", order_id="ord_789",
        status="NEW",
        condition={"user_id__not_exists": True}
    )
except ConditionError:
    print("Order already exists")

# Only update if current status matches
orders.update(
    user_id="usr_123", order_id="ord_789",
    set={"status": "SHIPPED"},
    condition={"status__eq": "PENDING"}
)

# Only delete if condition is met
orders.delete(
    user_id="usr_123", order_id="ord_789",
    condition={"status__eq": "CANCELLED"}
)

OR Conditions

# Update if status is PENDING or DRAFT
orders.update(
    user_id="usr_123", order_id="ord_789",
    set={"status": "CANCELLED"},
    condition_or=[
        {"status__eq": "PENDING"},
        {"status__eq": "DRAFT"}
    ]
)

Combined AND + OR

orders.update(
    user_id="usr_123", order_id="ord_789",
    set={"status": "SHIPPED"},
    condition={"version__eq": 3},
    condition_or=[
        {"status__eq": "PENDING"},
        {"status__eq": "CONFIRMED"}
    ]
)
# Evaluates: (version = 3) AND (status = PENDING OR status = CONFIRMED)