具有＆gt; 1列的非结构dest类型结构

Question

package main

import (
    "fmt"
    "github.com/jmoiron/sqlx"
    _ "github.com/lib/pq"
    "net/http"
    "log"
    "encoding/json"
    "time"
)

type serverStructV1 struct {
    id         int       `db:"id"`
    hostname   string    `db:"hostname"`
    nickname   string    `db:"nickname"`
    locationIp string    `db:"location_ip"`
    updatedAt  time.Time `db:"updatedAt"`
}

func serversHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello, world/n")

    db, err := sqlx.Open("postgres", "postgres://afdata:afdata@/afdata?sslmode=disable")
    if err!= nil{
        log.Fatal(err)
    }
    defer db.Close()
    err = db.Ping()
    if err != nil {
        panic(err.Error())
    }

    serversdisplay := []serverStructV1{}
    err = db.Select(&serversdisplay, "select id,hostname,nickname,location_ip,updatedAt from afdata.serversV1")
    if err != nil {
        log.Fatal(err)
    }
}

当我运行它时，如果我改变

，它会在＆gt; 1列（5）上显示on-struct dest类型结构

 err = db.Select(&serversdisplay, "select id,hostname,nickname,location_ip,updatedAt from afdata.serversV1")

进入

 err = db.Select(&serversdisplay, "select id from afdata.serversV1")

结果变为null。 我使用psql测试选择查询，它可以返回NOT NULL结果。但即使列匹配，它也会返回null。它连接到数据库，但没有得到查询结果。