Dynamic table names in Entity Framework linq

Question

I\'m using Entity Framework 6 with ASP.Net MVC 5. When using a database context object, is there a way to use a variable for the table name, without having to manually write

Answer 1

In addition to the helpful answers above, I also want to add this in case it helps someone else.

• If you are getting this error on the "Where" clause in Mark's answer:

  'DbSet does not contain a definition for 'Where' and no acceptable extension method 'Where' accepting an argument of the type 'DbSet' could be found.

  Installing the Nuget Package "System.Linq.Dynamic.Core" made the error disappear for us.

• If you need to access the LINQ methods and the column names from the table, you can code something like this:

  var tableName = "MyTableName"; 
  var tableClassNameSpace = "MyProject.Models.EntityModels";
  
  using (var dbContext = new MyEntities()) 
  {
       var tableClassName = $"{tableClassNameSpace}.{tableName}";
       var dynamicTableType = Type.GetType(tableClassName);      // Type
       var dynamicTable = sgrContext.Set(dynamicTableType);      // DbSet
  
       var records = dynamicTable
             .AsQueryable()
             .ToDynamicList()
             .OrderBy(d => d.MyColumnName)
             .Select(d => new { d.MyColumnName })
             .ToList();
  
        // do stuff
  }
  

Answer 2

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