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How to create Expression Tree for multiple column OrderBy Expression

I have create an orderby expression for my EF generic Repository as following string command = orderByDesc ? "OrderByDescending" : "OrderBy";

var type = typeof(T);

var property = type.GetProperty(orderby);

var parameter = Expression.Parameter(type, "p");

var propertyAccess = Expression.MakeMemberAccess(parameter, property);

var orderByExpression = Expression.Lambda(propertyAccess, parameter);

var resultExpression = Expression.Call(typeof(Queryable), command, new Type[] { type, property.PropertyType },

                       items.Expression, Expression.Quote(orderByExpression));
items = items.Provider.CreateQuery<T>(resultExpression);

Now I want to create the Expression with 2 columns for ordering and wasn't able to find out something helpful.

Please help me to create an orderby expression with 2 columns.

Solution

  • Ordering by multiple columns in LINQ works by calling OrderBy() followed by zero or more calls to ThenBy(). You can't do this using a single call to OrderBy().

    For example, if you can want to sort by the columns a and b, you will have to generate an expression that looks something like:

    items.OrderBy(p => p.a).ThenBy(p => p.b)