StackOverflowException in EF Query with Large Expression Tree

Question

I'm using EF 5 to perform a select requiring a multitude of Where conditions.

One of those conditions is to include only records where a Code field is in a list of codes provided by the UI (e.g. SQL translation: AND Code IN (123, 456)).

To achieve that, I build an expression tree based on this post, with the code:

static public Expression<Func<TElement, bool>> 
    BuildContainsExpression<TElement, TValue>(
        Expression<Func<TElement, TValue>> valueSelector, 
        IEnumerable<TValue> values)
{
    if (null == valueSelector)
    {
        throw new ArgumentNullException("valueSelector");
    }
    if (null == values) { throw new ArgumentNullException("values"); }

    ParameterExpression p = valueSelector.Parameters.Single();
    if (!values.Any())
    {
        return e => false;
    }

    var equals = 
        values.Select(value => (Expression)Expression.Equal(
            valueSelector.Body, 
            Expression.Constant(value, typeof(TValue))));

    var body = 
        equals.Aggregate<Expression>((accumulate, equal) => 
            Expression.Or(accumulate, equal));

    return Expression.Lambda<Func<TElement, bool>>(body, p);
}

The code is used like:

// List<long> desiredCodes is provided by the UI
containsExpression = LinqToEntitiesUtil.BuildContainsExpression<MyClass, long>
    (my => my.Code, desiredCodes);    

// In the actual code there are several other Where conditions as well
var matching = ctx.MyClasses.Where(containsExpression).Select(my => my);

This works perfectly when desiredCodes is reasonably sized. However, when the list contains a little over 1000 codes, I get a StackOverflowException the moment the matching iterator is evaluated.

Questions

Is there another way to implement the Contains requirement that is not vulnerable to a StackOverflowException?

Is there an upper limit on the size of the generated SQL imposed by SQL (SQL Server 2012)?

64K statement size limit. http://stackoverflow.com/questions/1869753/maximum-size-for-a-sql-server-query-in-clause-is-there-a-better-approach followed by issues that occur before. perhaps stacksize issue. — phil soady, Feb 19 '13 at 01:57

score 1 · Accepted Answer · answered May 06 '13 at 07:24

We experience the same problem, and after I've analyzed the bug, the only workaround as of now is to write the query manually (e.g. generate the IN (...) by string.Join() or something), since EF seems to build the statement by recursively walk the expression three.

StackOverflowException in EF Query with Large Expression Tree

1 Answers1