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Version: 0.14

MS SQL Server

SQL Server sink only support the projector mode.

You need to run a gRPC server (sidecar or a standalone workload) accessible to the Connector to make the sink work.

Quick start

You can check the sample of SQL Server sidecar using NodeJS.

Both samples contain the following:

  • Code generated from proto-files by language-specific Protobuf transpiler
  • MongoDB-oriented projections DSL for some of the supported operations
  • Bootstrap code for the gRPC server
  • Actual projections for events produced by the sample app

Those examples can help you to understand the concept and implement your own projectors.

Projector sidecar

You can create the projector gRPC server using any language or stack. The server must support bidirectional streaming, and implement the gRPC sidecar interface as described on the gRPC projector page. The Project operation of the Projection server returns the ProjectionResponse message, where the operation field should contain a SQL statement to execute:

syntax = "proto3";

package projection;

option csharp_namespace = "Eventuous.Connector.EsdbSqlServer";

message Execute {
string sql = 1;

For example (using TypeScript), with a helper function execute defined as:

import {AnyEventHandlerMap, project, WrapToAny} from "./common";
import {Execute} from "./compiled/proto/project";

export const execute = <T>(eventType: string, handler: (event: T) => string): AnyEventHandlerMap =>
e => {
const update = {sql: handler(e)};
return Execute.fromPartial(update);

You can return SQL inserts or updates based on different event types:

import {Projector} from "./common";
import {execute} from "./sqlProjectors";
import {PaymentRegistered, RoomBooked} from "./eventTypes";

export const sqlProjections: Projector = [
event =>
`INSERT INTO Bookings (BookingId, RoomId, GuestId)
VALUES ('${event.bookingId}', '${event.roomId}', '${event.guestId}')`
event =>
`UPDATE Bookings
SET OutstandingAmount = ${event.amount}
WHERE BookingId = '${event.bookingId}'`


There are two sections to configure in the Connector configuration: target and grpc. The target section specified the SQL Server configuration, and the grpc section contains the sidecar URL (your service).

For the SQL Server sink, you need to configure the following parameters:

  • connectionString: The connection string to SQL Server, including all the credentials and the database name

You can only project to one database using a single Connector instance.

Here's the sample configuration for this connector:

connectorId: "esdb-sql-connector"
connectorAssembly: "Eventuous.Connector.EsdbSqlServer"
enabled: true
exporters: [zipkin]
enabled: true
exporters: [prometheus]
traceSamplerProbability: 0
connectionString: "esdb://localhost:2113?tls=false"
concurrencyLimit: 1
connectionString: "Server=localhost;Database=test;User=sa;Password=Your_password123;Encrypt=True;TrustServerCertificate=True"
uri: "http://localhost:9091"
credentials: "insecure"