github.com/shogo82148/std@v1.22.1-0.20240327122250-4e474527810c/database/sql/example_cli_test.go (about)

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package sql_test
     6  
     7  import (
     8  	"github.com/shogo82148/std/context"
     9  	"github.com/shogo82148/std/database/sql"
    10  	"github.com/shogo82148/std/flag"
    11  	"github.com/shogo82148/std/log"
    12  	"github.com/shogo82148/std/os"
    13  	"github.com/shogo82148/std/os/signal"
    14  )
    15  
    16  func Example_openDBCLI() {
    17  	id := flag.Int64("id", 0, "person ID to find")
    18  	dsn := flag.String("dsn", os.Getenv("DSN"), "connection data source name")
    19  	flag.Parse()
    20  
    21  	if len(*dsn) == 0 {
    22  		log.Fatal("missing dsn flag")
    23  	}
    24  	if *id == 0 {
    25  		log.Fatal("missing person ID")
    26  	}
    27  	var err error
    28  
    29  	// ドライバを開く場合、通常、データベースへの接続は試みられません。
    30  	pool, err = sql.Open("driver-name", *dsn)
    31  	if err != nil {
    32  
    33  		// これは接続エラーではなく、DSN解析エラーや他の初期化エラーです。
    34  		log.Fatal("unable to use data source name", err)
    35  	}
    36  	defer pool.Close()
    37  
    38  	pool.SetConnMaxLifetime(0)
    39  	pool.SetMaxIdleConns(3)
    40  	pool.SetMaxOpenConns(3)
    41  
    42  	ctx, stop := context.WithCancel(context.Background())
    43  	defer stop()
    44  
    45  	appSignal := make(chan os.Signal, 3)
    46  	signal.Notify(appSignal, os.Interrupt)
    47  
    48  	go func() {
    49  		<-appSignal
    50  		stop()
    51  	}()
    52  
    53  	Ping(ctx)
    54  
    55  	Query(ctx, *id)
    56  }