查询foreach循环 [英] Query in foreach loop

问题描述

我尝试在forreach中调用查询但它显示错误



我尝试过：

i try to call query in forreach but it shows error

What I have tried:

public static string Jqufunc(int yearP)
{
	string res = "[";
	ProjectdbEntities a = new ProjectdbEntities();
	var b = a.Catg_type;
	foreach (var c in b)
	{

		res += "'" + c.Catg_type1 + "',";
	}
	res = res.Substring(0, res.Length - 1);
	res += "]";

	var allprogs = a.Program_type;
	string res2 = "[";
	foreach (var pr in allprogs)
	{
		res2 += "{name: '" + pr.Prog_name + "',";
		var allcats = a.Catg_type;
		res2 += "data:[";


		var query = (a.Std_info.Join(a.Catg_type, stdtable => stdtable.Catg_id,
		catg => catg.Catg_id, (stdtable, catg) => new {stdtable, catg})
		.Join(a.Program_type, t => t.stdtable.Prog_id, prog => prog.Prog_id, (t, prog) => new {t, prog})
		.Join(a.Year_info, t => t.t.stdtable.year_id, yea => yea.year_id, (t, yea) => new {t, yea})
		.Where(t=>t.t.t.stdtable.year_id==yearP)
		.GroupBy(
		t =>
		new { t.t.t.catg.Catg_type1, t.t.prog.Prog_name, t.yea.year, t.t.t.stdtable.Catg_id },
		t => t.t.t.stdtable)
		.Select(g => new
		{
			g.Key.Catg_type1,
			g.Key.Prog_name,
			g.Key.year,
			g.Key.Catg_id,
			total_students = g.Select(p=>p.Catg_id).Distinct().Count()
		})).ToList();
		res2 = res2.Substring(0, res2.Length - 1);
		foreach(var ab in res2)
		{
			res2 += query(yearP);
		}
	}
	res2 += "]";
	res2 += "},";
	return res + "*" + res2;

}

错误

'查询'是'变量'但是像'方法'一样使用

error
'query' is a 'variable' but is used like a 'method'

推荐答案

嗯......是的。它是。

查看消息：

Well...yes. It is.
Look at the message:

'query' is a 'variable' but is used like a 'method'

然后看看你如何创建和使用查询：

Then look at how you create and use query:

var query = (a.Std_info.Join(a.Catg_type, stdtable => stdtable.Catg_id,
             ...
                    })).ToList();
...
res2 += query(yearP);

query 是List< T>匿名类型。

您不能使用列表作为方法！



我不确定你到底是什么试图在这里做，但是...它不是一种方法， yearP 没有显示，所以它可能是列表的索引，在这种情况下你想要：

query is a List<T> of an anonymous type.
You can't use a list as a method!

I'm not sure what the heck you are trying to do here, but...it's not a method, yearP isn't shown, so it could be an index into the list in which case you'd want:

res2 += query[yearP];

但这不起作用，因为匿名类型没有加法运算符......

But that wouldn't work either because the anonymous type doesn't have a addition operator...

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