Linq动态选择列和表

Question

hello how I do dynamic select column query ?

example

 CrewEntities _DbEntities = new CrewEntities(); // I'm using object context



  public class CrewItem
        {
            public string Name { get; set; }
            public string LastName { get; set; }
        }

//I want to list only name column

var NameList = GetDynamicColumn("Name"); 

or

I want to list only LastName column 

var LastNameList = GetDynamicColumn("Name");



publict List<CrewItem> GetDynamicColumn(string Columm)
{
   var query = from p in _DbEntities.t_Crew
               select p.??? ;
}

and How do, I do dynamic select table query?

example

my sql table >> t_Crew , t_Person

var crewTable = GetDynamicTable("t_Crew");
var personTable = GetDynamicTable("t_Person");


    publict List<CrewItem> GetDynamicTable(string tableName)
    {
       var query = from p in _DbEntities.???
                   select p;
    }

thank you

Answer 1

For the second part of your question, If you are using Linq2SQL fro getting dynamic table data you can use this query

public IQueryable<TEntity> GetDynamicTable<TEntity>()
{
   return  _DbEntities.GetTable<TEntity>().Select(i => i);
}

or for having filter (where) you can write:

public IQueryable<TEntity> GetDynamicTable<TEntity>(Expression<Func<TEntity, bool>> expression)
{
   return  _DbEntities.GetTable<TEntity>().Select(i => i).Where(expression).AsQueryable();
}