go-query-context-sample

main.go

package main

import (
	"context"
	"database/sql"
	"fmt"
	"time"

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

func main() {
	ctx := context.Background()
	db, err := sql.Open("mysql", "root@tcp(127.0.0.1:3306)/mysql")
	if err != nil {
		panic(err)
	}

	ctx, cancel := context.WithTimeout(ctx, time.Millisecond*6000)
	defer cancel()

	rows, err := db.QueryContext(ctx, "select sleep(5) as v")
	if err != nil {
		switch err {
		case context.DeadlineExceeded:
			fmt.Printf("deadline found: %+v\n", err)
		default:
			fmt.Printf("other error: %+v\n", err)
		}
		return
	}
	defer rows.Close()

	for rows.Next() {
		var v string
		if err := rows.Scan(&v); err != nil {
			panic(err)
		}
		fmt.Printf("%+v\n", v)
	}
}