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Dynamic table name in linq

In your DbContext class, add a method say called Set that returns:

public DbSet Set(string name)
{
  // you may need to fill in the namespace of your context
  return base.Set(Type.GetType(name));
}

Which you can query like this:

using (var db = new YourDataContext())
{
  // Since your DbSet isn't generic, you can can't use this:
  // db.Set("Namespace.EntityName").AsQueryable().Where(a=> a.HasSomeValue...
  // Your queries should also be string based.
  // Use the System.Linq.Dynamic nuget package/namespace
  var results = db.Set("Namespace.EntityName")
    .AsQueryable()
    .Where("SomeProperty > @1 and SomeThing < @2", aValue, anotherValue);
  // you can now iterate over the results collection of objects
}

More information on System.Linq.Dynamic can be found here

LINQ Select from dynamic tableName string

The var query = table.Where(....).Select(...) is the correct move as it allows reflection for the query builder at runtime. However, t.AccountID is an error because of the type of t remains unknown.

I've previously used a similar approach in LINQ to SQL, using System.Linq.Expressions.Expression, e.g.:

    // NOT TESTED
    var table=context.GetTable(dynamicTableName);
    var theT=table.Experssion; // actually, I forget. DynamicExpression  or MemberBinding? or
    var theField=Expression.Field(theT, "AccountID"); // or dynamic name
    var query=table.Where(Expression.Equal(theField, accID);
    var recList=query.ToList<object>();

If your object has a common interface there is a simpler syntax:

IQueryable<MyInterface> table = context.GetTable("table") as IQueryable<MyInterface>;
    var recList=from r in table
                where table.AccountID == ac // if your AccountID is on MyInterface
                select table;

If you only have a few tables to support, you could do this as well:

    IQueryable<MyInterface> table;
    if("table1"==tableName)
       table=_db.table1
    elseif("table2"==tableName)
       table=_db.table2
    elseif("table3"==tableName)
       table=_db.table3
    else
       throw exception

Dynamic Table Names in Linq to SQL

You can call the ExecuteQuery method on the DataContext instance. You will want to call the overload that takes a Type instance, outlined here:

http://msdn.microsoft.com/en-us/library/bb534292.aspx

Assuming that you have a type that is attributed correctly for the table, passing that Type instance for that type and the SQL will give you what you want.

dynamic table name in Entity

Your question isn't very clear, but if you mean that You wanna do it in a generic way, then yes that is possible. You can take advantage of the Set<T> method. For example:

public void LoadToGrid<T>(GridType grid) where T: class, new() {
    grid.DataSource = dbContext.Set<T>().ToList();
}

And to customize the data fields in your grid, your can add this overload

public void LoadToGrid<T>(GridType grid, Expression<Func<T,Object>> selectExpression) where T: class, new() {
    grid.DataSource = dbContext.Set<T>().Select(selectExpression).ToList();
}

Dynamic table names in Entity Framework linq

Here's a simple solution using a switch to associate a particular Type to a table. You could also maintain use some sort of Dictionary<string, Type> object.

var tableName = "Table1";
// Get proper return type.
Type returnType;
switch(tableName) {
    case "Table1":
        returnType = typeof(Table1EntityType);
        break;
    case "Table2":
        returnType = typeof(Table2EntityType);
        break;
}
var query = context.Set(returnType);
// Filter against "query" variable below...
var result = query.Where(...);

-or-

var tableName = "Table1";
Dictionary<string, Type> tableTypeDict = new Dictionary<string, Type>()
{
    { "Table1", Table1Type },
    { "Table2", Table2Type }
}; 
var query = context.Set(tableTypeDict[tableName]);
// Filter against "query" variable below...
var result = query.Where(...);

EDIT: Modified for Entity Framework

EDIT2: Use typeof per @thepirat000 's suggestion

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