build out dynamic query in csharp

Building a dynamic query in C# involves the use of expression trees to build and execute queries at runtime. Here's a basic example of how to build a dynamic query that filters a list of objects based on a specified property and value:


main.cs
public IEnumerable<T> FilterList<T>(IEnumerable<T> list, string property, object value)
{
    var param = Expression.Parameter(typeof(T), "x");
    var prop = Expression.Property(param, property);
    var val = Expression.Constant(value);
    var equal = Expression.Equal(prop, val);
    var lambda = Expression.Lambda<Func<T, bool>>(equal, param);

    return list.Where(lambda.Compile());
}
393 chars
11 lines

Here's how you can use the function to filter a list of Person objects based on their Age property:


main.cs
var people = new List<Person>
{
    new Person { Name = "Alice", Age = 25 },
    new Person { Name = "Bob", Age = 30 },
    new Person { Name = "Charlie", Age = 35 }
};

var filteredPeople = FilterList(people, "Age", 30);
222 chars
9 lines

The resulting filteredPeople list will contain only the Person object with an Age of 30.

Note that this is just a basic example, and you can modify the FilterList function to handle more complex queries using additional expression tree operations such as AndAlso and OrElse.

similar csharp code snippets

dynamic sql query filtering on table on view in csharp

dynamic sql query filterin in csharp

dynamic sql query filtering in csharp

create a sql server queue processor in csharp

create a sql server service broker queue processor in csharp

get data from db by id in csharp

generate dynamic query filtering in csharp

query to reserve a slot in csharp

create a dynamic resultset in csharp

query sql database in csharp

related categories