Query Language

Liven uses a pipeline-based query language. Compose stages with | to build complex data flows from simple parts.

How It Works

Every query starts with a from("stream_name") stage that selects a stream. You then chain additional stages with the pipe operator (|) to filter, transform, aggregate, and enrich the data. Terminal dot-methods like .insert() or .listen()execute the query.

from("events")                                          // Select stream
  | filter(amount > 100)                                // Filter records
  | group(status, count())                              // Group & aggregate
  | sort(timestamp, desc)                               // Sort results
  | limit(50)                                           // Cap at 50 records

Query Types

There are three classes of operations:

• Read queries — pipeline stages that filter, transform, and analyze existing data. They return matching records.
• Write queries — terminal dot-methods that insert, upsert, update, or delete data. They return a status record.
• Subscriptions — the .listen() suffix turns any read query into a real-time stream.

Quick Examples

Insert a record

from("users").insert("user_1", {name: "Alice", role: "admin"})

Query with a filter

from("orders") | filter(amount > 100 and status == "completed") | count()

Real-time subscription

from("events") | filter(type == "error") .listen()