How to Work with Databend in Golang

Before You Begin

• Databend : Make sure Databend is running and accessible, see How to deploy Databend.

Golang

This guideline show how to connect and query to Databend using Golang.

We will be creating a table named books and insert a row, then query it.

package main

import (
    "database/sql"
    "fmt"
    "log"

    _ "github.com/go-sql-driver/mysql"
)

const (
    username = "root"
    password = ""
    hostname = "127.0.0.1:3307"
    dbname   = "book_db"
)

type Book struct {
    Title   string
    Author string
    Date   string
}

func dsn(dbName string) string {
    return fmt.Sprintf("%s:%s@tcp(%s)/%s", username, password, hostname, dbName)
}

func main() {
    db, err := sql.Open("mysql", dsn(dbname))

    if err != nil {
        log.Fatal(err)
    }
    defer db.Close()

    err = db.Ping()
    if err != nil {
        log.Fatal(err)
    }
    log.Println("Connected")

    // Create db if do not exist
    dbSql := "create database if not exists book_db"
    _, err = db.Exec(dbSql)
    if err != nil {
        log.Fatal(err)
    }
    log.Println("Create database book_db success")

    // Use book_db database
    _, err = db.Exec("use book_db")
    if err != nil {
        log.Fatal(err)
    }

    // Create table.
    sql := "create table if not exists books(title varchar(255), author varchar(255), date varchar(255))"
    _, err = db.Exec(sql)
    if err != nil {
        log.Fatal(err)
    }
    log.Println("Create table: books")

    // Insert 1 row.
    sql = "insert into books values('mybook', 'author', '2022')"
    _, err = db.Exec(sql)
    if err != nil {
        log.Fatal(err)
    }
    log.Println("Insert 1 row")

    // Select.
    res, err := db.Query("SELECT * FROM books")
    if err != nil {
        log.Fatal(err)
    }

    for res.Next() {
        var book Book
        err := res.Scan(&book.Title, &book.Author, &book.Date)
        if err != nil {
            log.Fatal(err)
        }

        log.Printf("Select:%v", book)
    }

}