Question

I have an issue that I would appreciate any help with.

Background – I have a database that holds a string (i.e. – StackOverFlow) and I need to compare a passed in value to that string and make it case sensitive.

Right now I have a connection to the database (using EF 4), an IRepo<T> interface (which I use to access the table) and a FindAllMatching method that returns an IQueryable<table> and takes in an Expression<Func<tableName, bool>> expression parameter.

Repo class:

public class TableRepo : IRepo<table>{
  private EF4Entity _dc = new EF4Entity();
  public IQueryable<table> FindAllMatching(Expression<Func<table, bool>> expression)
  {
    return _dc.table.Where(expression);
  }
}

Calling Code:

public class CallingClass
{
  public void CallingMethod(string enteredStringFromTextBoxOnFrontEnd)
  {
    var tableDB = new TableRepo();
    var returnValue = tableDB.FindAllMatching(x => x.ColumnInTableThatHoldsString.CompareTo(enteredStringFromTextBoxOnFrontEnd) ==0);
  }
}

Right now, when I pass in a string that matches what is in the table in every way but in case (stackoverflow as opposed to StackOverFlow) the returnValue actually returns a row from the table. If the value that is passed in doesn’t match the value contained in the database table exactly, I want it to return null or a count of zero.

I have tried doing .Equals(enteredStringFromTextBoxOnFrontEnd, StringComparison.OrdinalIgnoreCase) and all the other StringComparison values and nothing compares case.

If you need more information please don’t hesitate to ask.

Thank you,

Tim

Answer 1

Linq To Sql uses the database compare rules.

You need to add an extra IEnumerable.Where at the end to do a local filtering of the result

var returnValue = (ItableDB.FindAllMatching(x => x.ColumnInTableThatHoldsString == enteredStringFromTextBoxOnFrontEnd) as IEnumerble<TableRepo>).Where(x => x.ColumnInTableThatHoldsString == enteredStringFromTextBoxOnFrontEnd);