Go

Use RisingWave in your Go application

As RisingWave is wire-compatible with PostgreSQL, you can use third-party PostgreSQL drivers to interact with RisingWave from your Go applications.

In this guide, we use the pgx driver to connect to RisingWave.

Run RisingWave

To learn about how to run RisingWave, see Run RisingWave.

Install the pgx driver

Run the following command to install the pgx driver:

go get github.com/jackc/pgx/v4

Connect to RisingWave

To connect to RisingWave via pgx:

package main

import (
 "context"
 "fmt"
 "log"

 "github.com/jackc/pgx/v4"
)

func main() {
         // Please replace the placeholders with the actual credentials.
 connStr := "postgres://USER:PASSWORD@localhost:4566/DATABASE"
 conn, err := pgx.Connect(context.Background(), connStr)
 if err != nil {
  log.Fatalf("Unable to connect to RisingWave: %v\n", err)
 }
 defer conn.Close(context.Background())

 fmt.Println("Connected to RisingWave")
}

Create a source

The code below creates a source walk with the datagen connector. The datagen connector is used to generate mock data. The walk source consists of two columns, distance and duration, which respectively represent the distance and the duration of a walk. The source is a simplified version of the data that is tracked by smart watches.

Note that you need to place the code inside a function.

sql := `CREATE TABLE walk(distance INT, duration INT)
        WITH ( 
            connector = 'datagen',
            fields.distance.kind = 'sequence',
            fields.distance.start = '1',
            fields.distance.end  = '60',
            fields.duration.kind = 'sequence',
            fields.duration.start = '1',
            fields.duration.end = '30',
            datagen.rows.per.second='15',
            datagen.split.num = '1'
        ) FORMAT PLAIN ENCODE JSON`

_, err := conn.Exec(context.Background(), sql)
return err

Create a materialized view

The code in this section creates a materialized view counter to capture the latest total distance and duration. Note that you need to place the code inside a function.

sql := `CREATE MATERIALIZED VIEW counter AS 
        SELECT
            SUM(distance) as total_distance,
            SUM(duration) as total_duration
        FROM walk`

_, err := conn.Exec(context.Background(), sql)
return err

Query a materialized view

The code in this section queries the materialized view counter to get the real-time data. Note that you need to place the code inside a function.

sql := `SELECT * FROM counter`
rows, err := conn.Query(context.Background(), sql)
if err != nil {
 return err
}
defer rows.Close()

for rows.Next() {
 var total_distance, total_duration float64
 err = rows.Scan(&total_distance, &total_duration)
 if err != nil {
  return err
 }
 fmt.Printf("Total Distance: %.2f, Total Duration: %.2f\n", total_distance, total_duration)
}
return rows.Err()