Postgres中的Golang包装查询执行

Question

I am using the following code to wrap execution of aquery on a postgres database in a API I am building just to learn Go.

func QueryDB(qstring string) (*sql.Rows) {
    psqlInfo := fmt.Sprintf("host=%s port=%d user=%s dbname=%s sslmode=disable", host, port, user, dbname)
    db, err := sql.Open("postgres", psqlInfo)
    if err != nil {
      panic(err)
    }
    defer db.Close()

    //Ping method opens the connection
    err = db.Ping()
    if err != nil {
       panic(err)
    }

    //rows, err := db.Query("SELECT name FROM users WHERE age = $1", age)
    log.Printf("executing SQL %s
",qstring)
    rows, err := db.Query(qstring)
    if err != nil {
       log.Fatal(err)
    }
    return rows
}

my question is as per the documentation the db.Query() method accepts a query strgin and ...interface{} arguments otherwise. tried adding a second argument params ...interface{} to my function arguments and passing params as the second argument to the DB.Query method, and this doesn't work. it only seems to work if I specifically pull the arguments out of the interface slice. Any suggestions?

Answer 1

This may help you

Variadic functions can be called in the usual way with individual arguments. If you already have multiple args in a slice, apply them to a variadic function using func(slice...)

If you want send data from an slice, just add elipsis:

rows, err := db.Query(qstring, data...)
if err != nil {
   log.Fatal(err)
}

If you has the values separated in different variables:

rows, err := db.Query(qstring, val1, val2, val3, valN)
if err != nil {
   log.Fatal(err)
}