C# linq 中的简单选择查询
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时间：2020-08-10 00:43:08 来源:igfitidea点击:
simple select query in linq
提问by Cute Bear
Lets say I have a student table and I want to display the student with ID 1.
假设我有一个学生表，我想显示 ID 为 1 的学生。
SELECT *
FROM STUDENT ST
WHERE ST.ID = 1
This is how I achive this in Linq.
这就是我在 Linq 中实现的方式。
StudentQuery = from r in oStudentDataTable.AsEnumerable()
where (r.Field<int>("ID") == 1)
select r;
oStudentDataTable = StudentQuery.CopyToDataTable();
but what if I want to display the students with these ids 1,2,3,4,5..
但是如果我想显示这些 ID 为 1,2,3,4,5.. 的学生怎么办？
SELECT *
FROM STUDENT ST
WHERE ST.ID IN (1,2,3,4,5)
How can I achieve this in Linq?
我如何在 Linq 中实现这一目标？
采纳答案by Darren
回答by Piotr Zierhoffer
Try IEnumerable.Contains:
尝试IEnumerable.Contains：
var list = new List<int>(){1,2,3,4,5};
StudentQuery = from r in oStudentDataTable.AsEnumerable()
where (list.Contains(r.Field<int>("ID")))
select r;
oStudentDataTable = StudentQuery.CopyToDataTable();
回答by Arun Manjhi
Try this also :
也试试这个：
var list = new List<int> { 1, 2, 3, 4, 5 };
List<StudentQuery> result = (from r in oStudentDataTable.AsEnumerable()
where (list.Contains(r.Field<int>("ID"))
select new StudentQuery
{ /*
.Your entity here
.
*/
}).ToList<StudentQuery>();
