return a datafield from a database [Resolved]

Posted by Jopito under ASP.NET on 12/4/2013 | Points: 10 | Views : 2160 | Status : [Member] | Replies : 31

Write New Post |

Search Forums | Answered

Resolved Posts |

Un Answered Posts |

Forums Home

Hi pals,have got a method to return a field "country" from a sql database.The method doesnt return the lists from the database and am stuck how to figure it out,
Here is my method am using

public Nationality Getcountries(string countries)
{
Nationality country = db.Countries.SingleOrDefault(xz => xz.countries == countries);
return country;
}
where am i getting lost in this method?#Thanks

Mark as answer if satisfied

[Resolved]

Reply | Reply with Attachment

Alert Moderator

Responses

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 50

0	May be you are asking for LIKE search? public string GetNationalities(string nationals) { var query = (from countries in db.Registrations where countries.Nationalities.Contains(nationals) select countries.Nationalities).FirstOrDefault(); string returnValue = Convert.ToString(query); return returnValue; } NOTE: use Contains(), StartsWith(), or EndsWith() to mimick the LIKE operator of SQL Server. Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

May be you are asking for LIKE search?

public string GetNationalities(string nationals)
{
    var query = (from countries in db.Registrations
                 where countries.Nationalities.Contains(nationals)  
                 select countries.Nationalities).FirstOrDefault();
    string returnValue = Convert.ToString(query);
    return returnValue;
}

NOTE: use Contains(), StartsWith(), or EndsWith() to mimick the LIKE operator of SQL Server.

Mark This Response as Answer
--
Chandu
http://www.dotnetfunda.com/images/dnfmvp.gif

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: vishalneeraj-24503 on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	1). Please check whether your db.Countries have any records or not? 2). Are you getting any error in your code. Please check it too. Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: vishalneeraj-24503 on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	You can change your code as IQueryable<Nationality> countryquery = from country in db.Countries where country.countries == countries select country.SingleOrDefault(); Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	Here what is the type of Nationality ? Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	Nationality is a string datatype Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Kmandapalli on: 12/4/2013 [Member] Silver | Points: 25

0	Hi, Put debug point and check whether ur getting records from db or not. Try with FirstOrDefaukt instead of SingleOrDefault Mark as answer if satisfied.... Regards, Shree M. Kavya Shree Mandapalli Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	am getting the error Operator '==' cannot be applied to operands of type 'string' and 'System.Linq.IQueryable' after using the code public Nationality GetNationality() { IQueryable<Nationality> countryquery = from country in db.Countries where country.countries == countries select country.FirstOrDefault() Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

am getting the error
Operator '==' cannot be applied to operands of type 'string' and 'System.Linq.IQueryable' after using the code
public Nationality GetNationality()
{
IQueryable<Nationality> countryquery =
from country in db.Countries
where country.countries == countries
select country.FirstOrDefault()

Mark as answer if satisfied

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	public Nationality Getcountries(string countries) { Nationality country = db.Countries.FirstOrDefault(xz => xz.countries == countries).ToString(); return country; } Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	public Nationality GetNationality() { IQueryable<Nationality> countryquery = ( from country in db.Countries where country.countries == countries select country).FirstOrDefault() retrun countryquery } Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Kmandapalli on: 12/4/2013 [Member] Silver | Points: 25

0	Hi, Try with the following code: Nationality country = (from country in db.Countries where country.countries == countries select country.FirstOrDault).ToString(); Mark as answer if satisfied.... Regards, Shree M. Kavya Shree Mandapalli Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Kmandapalli on: 12/4/2013 [Member] Silver | Points: 25

0	Hi, Nationality country = (from country in db.Countries where country.countries == countries select country).ToString(); Mark as answer if satisfied.... Regards, Shree M. Kavya Shree Mandapalli Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	public Nationality Getcountries(string countries) { var cnty = (from country in db.Countries where country.countries == countries select country).FirstOrDefault(); string returnValue = Convert.ToString(cnty); return returnValue ; } Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

public Nationality Getcountries(string countries)  
{
var cnty = (from country in db.Countries 
           where country.countries == countries 
           select country).FirstOrDefault();
string returnValue = Convert.ToString(cnty);
return returnValue ;
}

Mark This Response as Answer
--
Chandu
http://www.dotnetfunda.com/images/dnfmvp.gif

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Kmandapalli on: 12/4/2013 [Member] Silver | Points: 25

0	Hi, Forgot to tell you, You cannot perform direct conversion from IQuerable to string. You first need to assign it to a variable and then perform conversion. var result = (...); string value = Convert.ToString(result); return value. Mark as answer if satisfied..... Regards, Shree M. Kavya Shree Mandapalli Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	Hi,am using this code but it cannot return anything and i got record in my databse public Nationality Getcountries(string countries) { var cnty = (from country in db.Countries where country.countries == countries select country).FirstOrDefault(); string returnValue = Convert.ToString(cnty); return returnValue ; Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Hi,am using this code but it cannot return anything and i got record in my databse
public Nationality Getcountries(string countries)
{
var cnty = (from country in db.Countries
where country.countries == countries
select country).FirstOrDefault();
string returnValue = Convert.ToString(cnty);
return returnValue ;

Mark as answer if satisfied

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	The table name is Registrations and has a column called Nationality.I dont want to return the whole contents but only the column Nationality in my method .I hope this makes ya get my intention pals Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	what is the value in returnValue ? Are you getting value to returnValue ? Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	Hi,am using this code but it cannot return anything and i got record in my databse public string Getcountries(string countries) { var cnty = (from country in db.Countries where country.countries == countries select country.Nationality ).FirstOrDefault(); string returnValue = Convert.ToString(cnty); return returnValue ; } Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Hi,am using this code but it cannot return anything and i got record in my databse

public string  Getcountries(string countries) 

{

var cnty = (from country in db.Countries 

 where country.countries == countries 

 select country.Nationality ).FirstOrDefault();

string returnValue = Convert.ToString(cnty);

return returnValue ;



}

Mark This Response as Answer
--
Chandu
http://www.dotnetfunda.com/images/dnfmvp.gif

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	The value is cnty as per the method what av used really Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	What are columns available in Registrations table? public string Getcountries(string countries) { var cnty = (from country in db.Registrations where country.countries == countries select country.Nationality ).FirstOrDefault(); string returnValue = Convert.ToString(cnty); return returnValue ; } Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

What are columns available in Registrations table?

public string  Getcountries(string countries)  
{ 
 var cnty = (from country in db.Registrations 
 
             where country.countries == countries  
 
             select country.Nationality ).FirstOrDefault(); 
 
 string returnValue = Convert.ToString(cnty); 
 return returnValue ; 
}

Mark This Response as Answer
--
Chandu
http://www.dotnetfunda.com/images/dnfmvp.gif

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	The columns are Username,Age,Password,Email and Nationality in my registrations table Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	Have you checked above solution? Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	public string Getcountries(string usrName) { var cnty = (from country in db.Registrations where country.UserName == usrName ...... Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	Hi,have tried all this solutions but cannot solve please Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	The columns are Username,Age,Password,Email and Nationality in my registrations table public string Getcountries(string countries) { var cnty = (from country in db.Registrations where country.countries == countries // Place your condition select country.Nationality ).FirstOrDefault(); string returnValue = Convert.ToString(cnty); return returnValue ; } what is the problem with this code? Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

The columns are Username,Age,Password,Email and Nationality in my registrations table

public string  Getcountries(string countries)   
{  
 var cnty = (from country in db.Registrations   
  
             where country.countries == countries    // Place your condition 
  
             select country.Nationality ).FirstOrDefault();  
  
 string returnValue = Convert.ToString(cnty);  
 return returnValue ;  
}

what is the problem with this code?

Mark This Response as Answer
--
Chandu
http://www.dotnetfunda.com/images/dnfmvp.gif

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	can the "List"method accomplish this? Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	Am not getting what is the problem with above code... Support link http://weblogs.asp.net/scottgu/archive/2007/06/29/linq-to-sql-part-3-querying-our-database.aspx http://weblogs.asp.net/scottgu/archive/2007/04/21/new-orcas-language-feature-query-syntax.aspx Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Am not getting what is the problem with above code...

Support link
http://weblogs.asp.net/scottgu/archive/2007/06/29/linq-to-sql-part-3-querying-our-database.aspx
http://weblogs.asp.net/scottgu/archive/2007/04/21/new-orcas-language-feature-query-syntax.aspx

Mark This Response as Answer
--
Chandu
http://www.dotnetfunda.com/images/dnfmvp.gif

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	It works using the method public List<Registrations> GetNationalities(string nationals) { IList<Registration>getnationalities = db.Registrations.Where(nationals =>nationals.Nationalities!=nationals).Distinct().ToList(); The issue is that it repeats the list of nationalities,thought i could use "distinct" for it to filter the list being returned it somehow....?? Thanks return getSources.ToList(); } Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

It works using the method
public List<Registrations> GetNationalities(string nationals)
{

IList<Registration>getnationalities = db.Registrations.Where(nationals =>nationals.Nationalities!=nationals).Distinct().ToList();

The issue is that it repeats the list of nationalities,thought i could use "distinct" for it to filter the list being returned it somehow....??
Thanks
return getSources.ToList();

}

Mark as answer if satisfied

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	Hi, You are checking for NOT EQUAL to condition... . Where(nationals =>nationals.Nationalities != nationals) ? Is it intentional or typo? Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	i checked that because it would mean in my previous code above that i would pass the value as a query string of type,you notice in my code this part ((public string Getcountries(string countries))) would mean that i enter the value to get ,i,e (countries) in my code,after i checked that it brought all the items since in the code behind i passed a value which is not in the database Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

i checked that because it would mean in my previous code above that i would pass the value as a query string of type,you notice in my code this part ((public string Getcountries(string countries))) would mean that i enter the value to get ,i,e (countries) in my code,after i checked that it brought all the items since in the code behind i passed a value which is not in the database

Mark as answer if satisfied

Jopito, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Bandi on: 12/4/2013 [Member] [MVP] Platinum | Points: 25

0	Means that you want to get the all records which doesn't satisfy the given nationality? Mark This Response as Answer -- Chandu http://www.dotnetfunda.com/images/dnfmvp.gif Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Jopito on: 12/4/2013 [Member] Starter | Points: 25

0	yeah,in my case,have onlyb predefined 5 records for nationalities,The five nationalities are the one s to appear in the dropdown,its jus a trial which i tried to check if it will work out Mark as answer if satisfied Jopito, if this helps please login to Mark As Answer. \| Alert Moderator

Latest Posts