所以这里我给你一个解决方案，试试这个从查询中得到field和type。

package main

import (
    "fmt"
    _ "github.com/lib/pq"
    "database/sql"
)

func main() {

    db, _ := sql.Open(
        "postgres",
        "user=postgres dbname=demo password=123456")

    rows, _ := db.Query("SELECT * FROM tableName;")

    columns, _ := rows.Columns()
    count := len(columns)
    values := make([]interface{}, count)
    valuePtr := make([]interface{}, count)

    for rows.Next() {

        for i, _ := range columns {
            valuePtr[i] = &values[i]
        }

        rows.Scan(valuePtr...)

        for i, col := range columns {

            var v interface{}

            val := values[i]

            b, ok := val.([]byte)

            if (ok) {
                v = string(b)
            } else {
                v = val
            }

            fmt.Println(col, v)
        }
    }
}

就像这个答案所暗示的那样，sqlx可能是一个不错的选择。
我个人使用db.Unsafe（）来忽略不需要的字段。

type MyTable struct {
    // list the fields you want here
    Name   string `db:"name"`
    Field1 string `db:"field1"`
}

db := try(sqlx.ConnectContext(context.Background(), "mysql",
    fmt.Sprintf("root:@tcp(%s:%d)/?charset=utf8mb4&timeout=3s", host, port)))
db = db.Unsafe()

rows := try(db.Queryx("select * from mytable"))
for rows.Next() {
    myTable := MyTable{}
    rows.StructScan(&myTable)
}