CODEWITHSUNDEEP
sql-serverlinq
nazmul.3026
nazmul.3026

Reputation: 1008

How do I write a conditional (IF DATA EXISTS) LINQ statement without repetition?

I need to write a Linq query where the condition like this:

bool ifexists =  db.Users.Any(u => u.id== 1);
IQueryable<modelname> query;
if(ifexists == true)
{
    query=my inner join linq;
    query = from s in query select s;
    return query.ToList();
}
else 
{
    query=my left join linq;
    query = from s in query select s;
    return query.ToList();
}

Now how I can write this Linq? Is there any way to write this linq in a single Linq statement - I don't want to write the linq twice?

Upvotes: 2

Views: 769

Answers (3)

Umakant Dubey
Umakant Dubey

Reputation: 35

   First create object of of database Context named **Objcontext** 
    now hold the variable in var the query would be like following 




 var Result = from a in Objcontext.tbl1  where !Objcontext.tbl2.Any(m=>(m.sid==a.aid)&&(m.mid==80))
    select a; 



 If data is exists in the databse it will cheack using !Objcontext 
    I hope it will helpfull

Upvotes: 0

StuartLC
StuartLC

Reputation: 107317

You can conditionally compose on an IQueryable before evaluating it against the database - this will allow you to at least partially DRY up the common actions on the different legs of your branching:

var query = db.SomeTable
    .AsQueryable() // Not needed if `db.SomeTable` is already a Queryable
    .Where(x => ** common predicates on x ** ));
    // NB : Do not materialize here!

if(exists) // Don't need == true
{
     query = query
      .Where(x => ** branch 1 predicates **));
}
else
{
     query = query
      .Where(x => ** branch 2 predicates **);
}
return query
  .Select(q => ** common fields to project **)
  .OrderBy(q => ** common ordering **)
  .ToList(); // Materialize right at the end

Upvotes: 3

Abu Huzaifa
Abu Huzaifa

Reputation: 21

You Want like That?

bool ifexists =  db.Users.Any(u => u.id== 1);

var query=ifexists==true ? (my inner join linq) : (my left join linq);

return query.ToList();

Upvotes: 1

Related Questions