Linq error: Sequence contains no elements 程序报异常:Sequence contains no elements。首先想到 Oracle 数据库中用到的 Sequence 对象,查之未超限,.NextVal、.CurrVal 都正常。Google 之,异常是 IQuerable<T>.First() 方法报的,当查询的结果集为空时,调用 First() 方法将报此异常,换用 FirstOrDefault() 方法...
Sequence contains no elements : LINQ error 1.错误意思:出现错误的原因是:你要从一个null中取的数据。2.错误的处理1,使用FirstOrDefault() 来代替 First()2、使用SingleOrDefault 来代替 Single3、使用 ElementAtOrDefault 来代替 .ElementAt4、如果是在Average, Sum等中报错1 2 3 4 5 6 var items = new ...
Today I got an exception saying "Sequence contains no elements " when using LINQ against Windows Azure tables. I did a quick search and found that it is due to that I used First<> instead of FirstOrDefault<> in my code. The below link explains the issue....
When you start playing with LINQ queries over sequences of elements (e.g. getting min / max value for enumerable source) sooner or later you will come across this one -- the InvalidOperationException (“Sequence contains no elements”). The problem occurs as by default queries like IEnumerabl...
Returns the first element of a sequence, or a specified default value if the sequence contains no elements. FirstOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Returns the first element of the sequence that satisfies a condition or a default value if no such element is found...
Returns the first element of the sequence that satisfies a condition or a default value if no such element is found. FirstOrDefault<TSource>(IEnumerable<TSource>) Returns the first element of a sequence, or a default value if the sequence contains no elements. ...
Returns the first element of the sequence that satisfies a condition or a default value if no such element is found. FirstOrDefault<TSource>(IEnumerable<TSource>) Returns the first element of a sequence, or a default value if the sequence contains no elements. ...
Returns the first element of the sequence that satisfies a condition or a default value if no such element is found. FirstOrDefault<TSource>(IEnumerable<TSource>) Returns the first element of a sequence, or a default value if the sequence contains no elements. GroupBy<TSource,TKey>(IEnumer...
If there are no items, First and Single will throw an InvalidOperationException with the message “Sequence contains no elements.” FirstOrDefault and SingleOrDefault protect you from the exception by returning the default, which is generally a null (Nothing in VB). Additionally, if you use ...
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