在rails里面写mysql语句问题

Question

quarterIdThe = params[:quarterThe_id].to_s #得到--本季度操作--对话框

department = params[:department_id] #得到选择的部门名称
upThe,downThe = getUpTheDownThe(quarterIdThe) #这是我自己写的一个方法，没有错误
busiesses = Business.find_by_sql["SELECT d.name FROM businesses AS b
JOIN employees AS e ON (b.employee_id = e.id)
JOIN departments AS d ON (e.department_id = d.id)
WHERE d.code = Department AND b.out_date <= UpThe AND b.out_date > DownThe ",{:Department => 'department',:UpThe=> 'upThe',:DownThe=> 'downThe'}]
我用的rails，这是在控制里面写的代码，主要是find_by_sql后边的代码有问题，总是提示说参数个数错误，求各位帮忙解决，或者是在model中写这个方法的话代码应该怎样写

Answer 1

[code="sql"]
Business.find_by_sql["SELECT d.name FROM businesses AS b
JOIN employees AS e ON (b.employee_id = e.id)
JOIN departments AS d ON (e.department_id = d.id)
WHERE d.code = ? AND b.out_date <= ? AND b.out_date > ?", department, upThe, downThe]

[/code]