报错"sqlMessage":"Unknown column 'admin' in 'where clause'"

在封装mysql查询适用到整个web服务器的时候遇到一个报错：

select * from admin_user where username=admin and password=3a0238ba5f11a798d0419c46461efd73
查询失败，原因：{"code":"ER_BAD_FIELD_ERROR","errno":1054,"sqlMessage":"Unknown column 'admin' in 'where clause'","sqlState":"42S22","index":0,"sql":"select * from admin_user where username=admin and password=3a0238ba5f11a798d0419c46461efd73"}

　　是在使用的时候，正确的写法是：

const {querySql}=require('../db')
function login(username,password){
  const sql=`select * from admin_user where username='${username}' and password='${password}'`
  return querySql(sql)
}


module.exports={
  login
}

参数要加""引号