Linq-To-SQL在空表中选择，更新和提交结果 [英] Linq-To-SQL select, update and commit results in empty Table

问题描述

给出:

using (DataContext ctx = new DataContext(props.ConnectionString))
{
    IQueryable<Email> emails = null;
    try
    {
       emails = ctx.Emails.Where(e => !(e.IsLocked || e.IsSent));
       foreach (var e in emails)
       {
           e.IsLocked = true;
       }
       ctx.SubmitChanges();
    }
}

// do something with emails here

为什么在SubmitChanges()之后电子邮件为空?有什么方法可以避免IsLocked设置为true后清空表?

Why is emails empty after SubmitChanges()? Is there any way to avoid emptying the Table after IsLocked is set to true?

推荐答案

表ctx.Emails可能不为空.每次调用集合emails时都会对其进行评估.

The table ctx.Emails is probably not empty. The collection emails is evaluated every time you call it.

如果要保留首次通话时返回的电子邮件，可以执行以下操作:

You could do this if you want to keep the emails return on the initial call:

emails = ctx.Emails.Where(e => !(e.IsLocked || e.IsSent)).ToList().AsQueryable();

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