How to Work with Databend in Golang
Before You Begin
- Databend : Make sure Databend is running and accessible, see How to deploy Databend.
- How to Create User
- How to Grant Privileges to User
Create Databend User
mysql -h127.0.0.1 -uroot -P3307
Create a User
mysql>
create user user1 identified by 'abc123';
Grants Privileges
Grants ALL
privileges to the user user1
:
mysql>
grant all on *.* to 'user1';
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.
main.go
main.go
package main
import (
"database/sql"
"fmt"
"log"
_ "github.com/go-sql-driver/mysql"
)
const (
username = "user1"
password = "abc123"
hostname = "127.0.0.1:3307"
)
type Book struct {
Title string
Author string
Date string
}
func dsn() string {
return fmt.Sprintf("%s:%s@tcp(%s)/", username, password, hostname)
}
func main() {
db, err := sql.Open("mysql", dsn())
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)
}
}
Golang mod
go mod init databend-golang
go.mod
module databend-golang
go 1.18
require github.com/go-sql-driver/mysql v1.6.0
Run main.go
go run main.go
Outputs
2022/04/13 12:20:07 Connected
2022/04/13 12:20:07 Create database book_db success
2022/04/13 12:20:07 Create table: books
2022/04/13 12:20:07 Insert 1 row
2022/04/13 12:20:08 Select:{mybook author 2022}
2022/04/13 12:20:08 Select:{mybook author 2022}