endswith causing confusion in linq. Have work around but....

endswith causing confusion in linq. Have work around but....

Postby kerrywales » Thu 13 May 2010 13:19

I Cannot see if this is a bug or my ignorance as the original logic and work around solution logic are so similar

I am building up a complex series of queries. This includes a drop down box for users to choose if they want to check "starting with", "Contains" or ends with (values 0,1 & 2)

My first draft class to do the query contains the following code. I use a lot of generalisation and common libraries. I use objects that can have variables created and set within the object through a function called SetCriteria. I can then get the value of the dynamic variable through GetCriteria (which returns null if it doesn't exist). This is a cut down, but salient, part of the code I am testing

object objhowSearchCompany = null;
object objCompany = null;
//param1 = private var name, param 2 is ref to local object to hold a copy
GetCriteria("howSearchCompany", out objhowSearchCompany);
GetCriteria("Company", out objCompany);

string company = (string)objCompany;
int howSearchCompany = (int)objhowSearchCompany;

var Query = (from Name in entity.TblMyName
where
(
//when a user doesn't fill the company field on the e-form the search object
//will not have a var company (so will be null) or
//blanked out (so will have length 0)
//presuming boolean conversion is good enough not to do the
//comparison if the search criteria is false
( company.Length == 0) ||
( company.Length == null) ||
( howSearchCompany == 0 && Name.TblName.Company.ToUpper().StartsWith(company.ToUpper()) ) ||
( howSearchCompany == 1 && Name.TblName.Company.ToUpper().Contains(company.ToUpper()) ) ||
( howSearchCompany == 2 && Name.TblName.Company.ToUpper().EndsWith(company.ToUpper()) )
)
select new
{
Name = Name.TblName.Surname.TrimEnd() + " " + Name.TblName.TblTitle.Description.TrimEnd() + " " + Name.TblName.Forename.TrimEnd(),
OIDName = Name.TblName.OIDRef,
OIDAddress = Name.TblAddresses.OIDAddress,
Company = Name.TblName.Company

}
);

If I compile without the where line including the EndsWith then the query works perfectly and provides the right results.
If I include the EndsWith then I get an inner exception error.


Now I have a work around that seems to stop giving me the innerexception error

object objhowSearchCompany = null;
object objCompany = null;
GetCriteria("howSearchCompany", out objhowSearchCompany);
GetCriteria("Company", out objCompany);

string company = "";
if (objCompany != null)
company = ((string)objCompany).ToUpper();
int howSearchCompany = (int)objhowSearchCompany;

var Query = (from Name in entity.TblMyName
where
(
( company.Length == 0) ||
( company.Length == null) ||
( howSearchCompany == 0 && Name.TblName.Company.ToUpper().StartsWith(company) ) ||
( howSearchCompany == 1 && Name.TblName.Company.ToUpper().Contains(company) ) ||
( howSearchCompany == 2 && Name.TblName.Company.ToUpper().EndsWith(company) )
)
select new
{
Name = Name.TblName.Surname.TrimEnd() + " " + Name.TblName.TblTitle.Description.TrimEnd() + " " + Name.TblName.Forename.TrimEnd(),
OIDName = Name.TblName.OIDRef,
OIDAddress = Name.TblAddresses.OIDAddress,
Company = Name.TblName.Company

}
);


Now the second version does NOT give me a run time inner exception error, which looking at the code baffles me because the GetCriteria for company in both sets of code returns the same value. An object containing "dan".

I do not like not understanding why one version works and the other not.
Can someone tell me why the first version fails?

Kerry
kerrywales
 
Posts: 52
Joined: Tue 05 Jan 2010 12:26

Postby Shalex » Mon 17 May 2010 13:29

1. Please specify the error message and your call stack.
2. Which version (x.xx.xx) of dotConnect for PostfreSQL are you using? You can find it via the Tools | PostgreSQL | About menu of Visual Studio.
3. Please send us a small test project with the DDL/DML script to reproduce the error.
Shalex
Devart Team
 
Posts: 7654
Joined: Thu 14 Aug 2008 12:44


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