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copied!<p>I've come up with a way to chunk the query into pieces - i.e. you give it 4000 values, so it might do 4 requests of 1000 each; with full Northwind example. Note that this might not work on Entity Framework, due to <code>Expression.Invoke</code> - but is fine on LINQ to SQL:</p> <pre><code>using System; using System.Collections.Generic; using System.Linq; using System.Linq.Expressions; using System.Reflection; namespace ConsoleApplication5 { /// SAMPLE USAGE class Program { static void Main(string[] args) { // get some ids to play with... string[] ids; using(var ctx = new DataClasses1DataContext()) { ids = ctx.Customers.Select(x => x.CustomerID) .Take(100).ToArray(); } // now do our fun select - using a deliberately small // batch size to prove it... using (var ctx = new DataClasses1DataContext()) { ctx.Log = Console.Out; foreach(var cust in ctx.Customers .InRange(x => x.CustomerID, 5, ids)) { Console.WriteLine(cust.CompanyName); } } } } /// THIS IS THE INTERESTING BIT public static class QueryableChunked { public static IEnumerable<T> InRange<T, TValue>( this IQueryable<T> source, Expression<Func<T, TValue>> selector, int blockSize, IEnumerable<TValue> values) { MethodInfo method = null; foreach(MethodInfo tmp in typeof(Enumerable).GetMethods( BindingFlags.Public | BindingFlags.Static)) { if(tmp.Name == "Contains" && tmp.IsGenericMethodDefinition && tmp.GetParameters().Length == 2) { method = tmp.MakeGenericMethod(typeof (TValue)); break; } } if(method==null) throw new InvalidOperationException( "Unable to locate Contains"); foreach(TValue[] block in values.GetBlocks(blockSize)) { var row = Expression.Parameter(typeof (T), "row"); var member = Expression.Invoke(selector, row); var keys = Expression.Constant(block, typeof (TValue[])); var predicate = Expression.Call(method, keys, member); var lambda = Expression.Lambda<Func<T,bool>>( predicate, row); foreach(T record in source.Where(lambda)) { yield return record; } } } public static IEnumerable<T[]> GetBlocks<T>( this IEnumerable<T> source, int blockSize) { List<T> list = new List<T>(blockSize); foreach(T item in source) { list.Add(item); if(list.Count == blockSize) { yield return list.ToArray(); list.Clear(); } } if(list.Count > 0) { yield return list.ToArray(); } } } } </code></pre>

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