如何从sql数据库备份一行？

I want to make a backup sql data function in golang. I have written a sample code which will backup the sql database and a command for table too. But I don't know that how to dump the one row data from sql into given path?

For database:

package main

import (
    "io/ioutil"
    "log"
    "os/exec"
)

func main() {
    cmd := exec.Command("mysqldump", "-P3306", "-hhost", "-uuser", "-ppassword", "database_name")
    stdout, err := cmd.StdoutPipe()
    if err != nil {
        log.Fatal(err)
    }

    if err := cmd.Start(); err != nil {
        log.Fatal(err)
    }

    bytes, err := ioutil.ReadAll(stdout)
    if err != nil {
        log.Fatal(err)
    }
    err = ioutil.WriteFile("./out.sql", bytes, 0644)
    if err != nil {
        panic(err)
    }

}

For table we can change the command like below:

cmd := exec.Command("mysqldump", "-P3306", "-hhost", "-uuser", "-ppassword", "database_name" "table_name")

For dump the row of a table what should I have to write please any suggestions with short code.

for example: dump that row where id is equals to 1