使用linq在asp.net中使用多个控件搜索多列

Question

Project_Detail pro = new Project_Detail(); 
string title=Ttitle.Text; 
string year1=Tyear.Text; 
string key = Tkeywrds.Text; 
string area = Ddl_area.Text; 
string categ = Ddl_catgry.Text; 
string tech = Ddl_tech.Text; 
string type =Ddl_type.Text; 

var q = from obj in da.Project_Details 
     where obj.Project_Title.Contains(title) 
       || obj.Submission_Date.Contains(year1) 
       || obj.Keywords.Contains(key) 
       || obj.Project_Area.Contains(area) 
       || obj.Project_Category.Contains(categ) 
       || obj.Project_Technology.Contains(tech) 
       || obj.Project_Type.Contains(type) 
     select obj; 

if (q != null) 
{ 
    DetailsView1.DataSource = q; 
    DetailsView1.DataBind(); 
} 
else 
{ 
    Literal1.Text = "Data not found"; 
} 

这段代码给出了表的最后一条记录，并且不给出其他条件结果。 我想要所有的条件的结果，并希望使用LIKE satatement。

Answer 1

q从不为空。不过，它可能是空的。所以，你应该更改您的代码

if (q.Any()) // <<----- 
{ 
    DetailsView1.DataSource = q; 
    DetailsView1.DataBind(); 
} 
else 
{ 
    Literal1.Text = "Data not found"; 
} 

Answer 2

您还可以使用计数方法.Count()

if (q.count()>0) 
{ 
    DetailsView1.DataSource = q; 
    DetailsView1.DataBind(); 
} 
else 
{ 
    Literal1.Text = "Data not found"; 
}