Predicate can't parse

[minik42]

Hi, I'm getting an error: predicate can't parse. This is my code:

public IEnumerable GetMessages(int recipientId, bool? isRead)
{
    var results = SetLimit(1, 10)
        .FindAll(x => x.Recipient_Id == recipientId && (isRead == null || x.IsRead == isRead));
    return results;
}

Is there any way to apply next conditions if for example value is not null as above?

[phnx47]

@minik42 Hi, problem with this part isRead == null, try something like this

public IEnumerable GetMessages(int recipientId, bool isRead)
{
    var results = SetLimit(1, 10)
        .FindAll(x => x.Recipient_Id == recipientId && x.IsRead == isRead);
    return results;
}

Check this out SqlGenerator.AppendWherePredicateQuery.cs#L82

[minik42]

Sure, but I want my parameters to be optional, that's why it is bool? instead of bool. When isRead is null i want SQL to ignore this, in EF I applied this conditions to IQueryable

[phnx47]

@minik42 It's difficult to parse. This library supports only simple expressions by design. Use Raw SQL or try this

public IEnumerable GetMessages(int recipientId, bool? isRead)
{
    if (isRead.HasValue) 
    {
        return SetLimit(1, 10)
            .FindAll(x => x.Recipient_Id == recipientId && x.IsRead == isRead);
    } 
    else 
    {
        return SetLimit(1, 10)
            .FindAll(x => x.Recipient_Id == recipientId);
    }
}