Question

我可能不明白RavenDb中的“In”扩展方法是如何工作的。我认为它相当于SQL世界中的IN命令，例如数字IN（1,2,3）。但它表现得很奇怪。

// i have 3 records - two with Normal severity, one with Low severity
using (var session = store.OpenSession())
{
    session.Store(new TestObject { Name = "o1", Severity = Severity.Normal });
    session.Store(new TestObject { Name = "o2", Severity = Severity.Low });
    session.Store(new TestObject { Name = "o3", Severity = Severity.Normal });
    session.SaveChanges();
}

// this writes the Low severity record, it seems correct
using (var session = store.OpenSession())
{
    var data = session.Query<TestObject>()
        .Where(o => o.Severity.In(new[] { Severity.Low }))
        .OrderBy(o => o.Name).ToList();
    data.ForEach(r => Console.WriteLine(r));
}

// this writes also the Low severity record, it still seems correct
using (var session = store.OpenSession())
{
    var data = session.Query<TestObject>()
        .Where(o => o.Severity.In(new[] { Severity.Low, Severity.High }))
        .OrderBy(o => o.Name).ToList();
    data.ForEach(r => Console.WriteLine(r));
}

// this writes all records, still seems correct
using (var session = store.OpenSession())
{
    var data = session.Query<TestObject>()
        .Where(o => o.Severity.In(
            new[] { Severity.High, Severity.Low, Severity.Normal }))
        .OrderBy(o => o.Name).ToList();
    data.ForEach(r => Console.WriteLine(r));
}

// but this does not write anything 
// despite there are 2 records with Normal severity
using (var session = store.OpenSession())
{
    var data = session.Query<TestObject>()
        .Where(o => o.Severity.In(new[] { Severity.High, Severity.Normal }))
        .OrderBy(o => o.Name).ToList();
    data.ForEach(r => Console.WriteLine(r));
}

// and this does not write anything either, 
// I just tried whether the order of values in the array matters
using (var session = store.OpenSession())
{
    var data = session.Query<TestObject>()
        .Where(o => o.Severity.In(new[] { Severity.Normal, Severity.High }))
        .OrderBy(o => o.Name).ToList();
    data.ForEach(r => Console.WriteLine(r));
}

或者我在RavenDb / Lucene引擎中发现了一个错误？

修改

我发现了另一件奇怪的事情。它必须按照枚举成员的字母顺序执行某些操作。当我将Severity.Normal重命名为Severity.A时，最后两个查询行为正确并返回结果。当我将Severity.Normal重命名为Severity.La时，它仍然有效（因为La＆lt; Low）。但是当我将Severity.Normal重命名为Severity.Lu（Lu＆gt; Low）时，它会中断并且最后两个查询不再返回结果。原始样本不起作用，因为正常＆gt;低。但我仍然想知道为什么会这样，因为这对我没有意义。

Answer 1

你正在遇到陈旧的索引，这就是你得到奇怪结果的原因。您需要等待索引首先完成。

RavenDb“In”运算符如何工作？

修改

1 个答案: