[Go言語] database/sqlパッケージを使ってみた ref: http://qiita.com/tenntenn/items/dddb13c15643454a7c3b

file0.txt

go get "github.com/go-sql-driver/mysql"

file1.txt

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

file10.txt

var cnnPool chan *sql.DB

func main() {
    cnnPool = make(chan *sql.DB, 10)
    for i := 0; i < cap(cnnPool); i++ {
        cnnPool <- sql.Open("mysql", "user:password@tpc(host:port)/dbname")
    }
}

func getFromDB() { 
    cnn := <-cnnPool
    defer func() {
        cnnPool <- cnn
    }()
    // cnnを使った処理
}

file2.txt

cnn := sql.Open("mysql", "user:password@tcp(host:port)/dbname")

file3.txt

id := 100
var name string

if err := cnn.QueryRow("SELECT name FROM person WHERE id = ?LIMIT 1", id).Scan(&name); err != nil {
    log.Fatal(err)
}

fmt.Println(id, name)

file4.txt

rows, err := cnn.Query("SELECT id, name FROM person")
if err != nil {
    log.Fatal(err)
}
defer rows.Close()

for rows.Next() {
    var id int
    var name string 
    if err := rows.Scan(&id, &name); err != nil {
        log.Fatal(err)
    }
    fmt.Println(id, name)
}

if err := rows.Err(); err != nil {
    log.Fatal(err)
}

file5.txt

result, err := cnn.Exec("UPDATE person SET name = ? WHERE id = ?", "Hogera", 100)
if err != nil {
    log.Fatal(err)
}

file6.txt

type Result interface {
        LastInsertId() (int64, error)
        RowsAffected() (int64, error)
}

file7.txt

tx, err := cnn.Begin()
if err != nil {
    log.Fatal(err)
}

file8.txt

tx.Commit()

file9.txt

func hoge(tx *sql.Tx) {
    defer func() {
        // panicがおきたらロールバック
        if err := recover(); err != nil {
            tx.Rollback()
        }
    }()
    // …
    tx.Exec(…)
}