SQL Sink

Status: Supported as Built-in Connector in rekuiper

rekuiper includes a built-in SQL sink connector implemented directly in Rust with sqlx. You do not need to compile or deploy Go dynamic plugins (.so files).

The SQL sink writes stream processing results into relational database tables.

Supported Database Engines

rekuiper supports the following relational database engines natively:

• PostgreSQL: postgres://username:password@hostname:5432/database or postgresql://...
• SQLite: sqlite://path/to/database.db or in-memory sqlite::memory:

::: note Legacy eKuiper compiled driver-specific Go plugins for MySQL, Oracle, and Microsoft SQL Server. rekuiper uses asynchronous Rust database connections via sqlx. For other database engines, use the REST Sink or external bridge microservices. :::

Configuration Properties

Property Name	Optional	Default Value	Description
url (or dburl)	False	None	Connection URL string for the target database.
table	False	None	Target database table name.
fields	True	Inferred	Array of column names to write. If omitted, rekuiper uses the keys of the output record. Dynamic keys must match [A-Za-z_][A-Za-z0-9_]* (keys containing spaces or punctuation are rejected to prevent SQL syntax errors).
sendSingle	True	false	When true, writes each event record individually.

rekuiper constructs parameterized SQL insert statements dynamically:

• SQLite uses ? parameter markers.
• PostgreSQL uses $1, $2, $3 positional parameter markers.
• Data values map to typed SQL parameters (integer, float, boolean, text, or untyped NULL).

Sample Usage

Write Records to PostgreSQL

The following rule processes sensor data and inserts the records into a PostgreSQL table:

{
  "id": "rule_pg_sink",
  "sql": "SELECT deviceId, temperature, humidity, ts FROM sensorStream WHERE temperature > 25.0",
  "actions": [
    {
      "log": {}
    },
    {
      "sql": {
        "url": "postgres://postgres:password@localhost:5432/telemetry",
        "table": "sensor_readings",
        "fields": ["deviceId", "temperature", "humidity", "ts"]
      }
    }
  ]
}

Write Records to SQLite

The following rule writes output records to a local SQLite database file:

{
  "id": "rule_sqlite_sink",
  "sql": "SELECT id, alertCode, message FROM alertStream",
  "actions": [
    {
      "sql": {
        "url": "sqlite:///var/data/alerts.db",
        "table": "alerts",
        "fields": ["id", "alertCode", "message"]
      }
    }
  ]
}

In-Memory SQLite for Testing

You can use an in-memory SQLite database for ephemeral testing without disk storage:

{
  "id": "rule_memory_sqlite",
  "sql": "SELECT * FROM demoStream",
  "actions": [
    {
      "sql": {
        "url": "sqlite::memory:",
        "table": "temp_results"
      }
    }
  ]
}