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() {
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()
