如何使用linq查询获取当前日期值? [英] how to get current date value using linq query?
问题描述
我试图调用以下linq查询来显示最新的日期值,但目前我一直在遇到编译错误:
API_09.Controllers.DateStampController.GetDate()':并非所有代码路径都返回值
< pre lang =c#> public IEnumerable< database_BD> GetDate()
{
var data =( from c 在 db.database_BD
选择 new
{
c.UploadDate
})。OrderByDescending(c = > c.UploadDate)。 Take( 1 )。ToList();
// 返回数据;
}
如果在返回行中添加,则会显示另一个编译错误。
请帮忙。我的查询方法是不正确的?
提前谢谢。
我想你不是正确使用选择新也需要使用ToList()然后应用OrderBy
尝试以下:
public IEnumerable< database_bd> GetDate()
{
var data =( from c 在 db.database_BD
选择 new
{
UploadDate = c.UploadDate
})。ToList()。OrderByDescending(c = > c.UploadDate).Take( 1 );
返回数据;
}
请试试这个....
公开IEnumerable的< database_BD> GetDate()
{
var data =(来自db.database_BD中的c
选择新的database_BD()
{
c.UploadDate
})。OrderByDescending(c => c.UploadDate).Take(1).ToList();
返回数据;
}
请尝试完整代码
public IEnumerable< database_BD> GetDate()
{
IEnumerable< database_BD> data =(来自db.database_BD中的c
选择新的database_BD()
{
UploadDate = c.UploadDate
})。OrderByDescending(c => c .UploadDate)。取(1).ToList();
返回数据;
}
public class database_BD
{
public datetime UploadDate {获得跨度>; set ; }
}
Hi,
I am trying to call the following linq query to display latest date value but currently i keep experiencing compiling error:
API_09.Controllers.DateStampController.GetDate()': not all code paths return a value
public IEnumerable<database_BD> GetDate()
{
var data = (from c in db.database_BD
select new
{
c.UploadDate
}).OrderByDescending(c => c.UploadDate).Take(1).ToList();
//return data;
}
if add in the return line, it shows another compiling error.
Please help. Is my approach to query is incorrect?
Thanks in advance.
I think you are not using the select new properly also need to use ToList() then apply OrderBy
Try below:
public IEnumerable<database_bd> GetDate() { var data = (from c in db.database_BD select new { UploadDate=c.UploadDate }).ToList().OrderByDescending(c => c.UploadDate).Take(1); return data; }
please try this one....
public IEnumerable<database_BD> GetDate() { var data = (from c in db.database_BD select new database_BD() { c.UploadDate }).OrderByDescending(c => c.UploadDate).Take(1).ToList(); return data; }
please try complete code
public IEnumerable<database_BD> GetDate() { IEnumerable<database_BD> data = (from c in db.database_BD select new database_BD() { UploadDate = c.UploadDate }).OrderByDescending(c => c.UploadDate).Take(1).ToList(); return data; }
public class database_BD { public datetime UploadDate{ get; set; } }
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