subscribe Statement
The subscribe
statement creates a subscription to a data stream.
Syntax
subscribe <stream_name>
Description
This statement establishes a subscription connection to a stream, routing all incoming data to the console. Each subscription receives a unique identifier for later management.
Parameters
stream_name
: Name of the stream to subscribe to (must be a valid identifier)
Examples
Basic Subscription
subscribe sensor_data
subscribe events
subscribe logs
Multiple Subscriptions
subscribe temperature_stream
subscribe humidity_stream
subscribe pressure_stream
Behavior
- Creates a subscription with a unique ID
- Prints received data to the console in the format:
📡 [stream_name]: data
- Subscription remains active until manually unsubscribed
- Multiple subscriptions can be created to the same stream
- Subscription ID is returned for later unsubscription
Output Format
When data is received, it's printed in this format:
📡 [sensor_data]: { "id": "sensor1", "temperature": 23.5, "timestamp": 1640995200 }
📡 [events]: { "type": "login", "user": "alice", "time": 1640995200 }
Related Statements
- unsubscribe - Stop a subscription
- list - List active subscriptions
- create stream - Create streams to subscribe to
- insert into - Add data to subscribed streams