same Linq for two tables

Question

I need to do something like this,

My two tables have the same signature, but different class so It suppose to work but it is not working.

var myTable;

if (booleanVariable == true)
{
     myTable = table1;
}
else
{
     myTable = table2;
}


var myLinq1 = from p in myTable
          join r in myOtherTable
          select p;

In this case, I have to initialize myTable

I have tried also,

var myTable= table2;

if (booleanVariable == true)
{
     myTable = table1;
}

var myLinq1 = from p in myTable
          join r in myOtherTable
          select p;

then var is type table2, then it can't be changed to table1 type.

I need help, I don't want to make a copy paste of all the code. the linq query is huge, and it s nested with 5 or 6 queries. also I have to do this on 12 different methods.

Thanks a lot for your help.

Answer 1

Don't know if this will work, never tried it, but...

If both classes can implement the same interface or share a base class, could you maybe do:

var q = (booleanVariable) 
    ? from p in myTable1 select (ISomeInterface)p 
    : from p in myTable2 select (ISomeInterface)p;

If you use this often, you can put this into its own method - I believe it will return IQueryable<ISomeInterface>.

Then connect to the rest of the LINQ query using the LINQ methods instead of the LINQ C# syntax (i.e. OrderBy() instead of orderby). I just don't know if LINQ-to-SQL will be smart enough to translate this into the correct SQL query.

But I agree with Jon's comment - this is probably bad design, and should be revisited. If you can't reorganize the tables themselves, and if you only need read access, how about a view that unions the two tables together, then tie that view into your LINQ-to-SQL structure.

Answer 2

I am redesigning my Database. thanks for your answers and comments