我什么时候可以处置我的 DataContext？

发布于 2024-08-15 23:19:07 字数 1329 浏览 5 评论 0原文

举个例子：

MyDataContext context = new MyDataContext(); // DB connection established.
MyTableRecord myEntity = myDataContext.Table.FindEntity(12345); // retrieve entity

假设我的实体与其他表有关系，我可以通过

foreach (MyEntity.RelatedTable 中的 var record) 访问这些

表，我是否需要在第二行之后保持 DataContext 处于活动状态才能访问实体的财产或者是否足够安全可以处置？

我了解 Linq to SQL 使用延迟执行，因此我想知道它是否仅在您最初检索实体时使用延迟执行，还是在访问相关表记录时也使用延迟执行。

示例

var userRepo = new UserRepository(); // creates new DataContext
var auditRepo = new AuditRepository(); // creates new DataContext
var activeUsers = userRepo.FindActiveUsers();
foreach (var user in activeUsers)
{
    // do something with the  user
    var audit = new Audit();
    audit.Date = DateTime.Now;
    audit.UserID = user.ID;
    auditRepo.Insert(audit);
}

我的存储库中的插入方法调用 SubmitChanges。那么上面的情况是否可以接受，或者这是浪费连接。我实际上应该这样做：

var userRepo = new UserRepository();
var activeUsers = userRepo.FindActiveUsers();
foreach (var user in activeUsers)
{
    // do something with user
    var audit = new Audit();
    audit.Date = DateTime.Now;
    audit.UserID = user.ID;
    user.Audits.Add(audit);
    userRepo.Save();
}

重新使用已经打开的 DataContext 吗？在打开高级数据上下文然后必须进行一些低级处理的情况下，您会做什么，我应该传递 userRepo 还是应该创建一个单独的存储库？

原文

Take the following example:

MyDataContext context = new MyDataContext(); // DB connection established.
MyTableRecord myEntity = myDataContext.Table.FindEntity(12345); // retrieve entity

Say my entity has relationships with other tables which I would access via

foreach (var record in MyEntity.RelatedTable)

Do I need to keep my DataContext alive after the 2nd line in order to access the properties of the entities or is it safe enough to dispose of?

I understand Linq to SQL uses delayed execution hence I am wondering if it only uses delayed execution when you initially retrieve the entity or whether it uses this when accessing the related table records aswell.

Example

var userRepo = new UserRepository(); // creates new DataContext
var auditRepo = new AuditRepository(); // creates new DataContext
var activeUsers = userRepo.FindActiveUsers();
foreach (var user in activeUsers)
{
    // do something with the  user
    var audit = new Audit();
    audit.Date = DateTime.Now;
    audit.UserID = user.ID;
    auditRepo.Insert(audit);
}

My insert method in my repo calls SubmitChanges. So is the above acceptable, or is this a waste of a connection. Should I realistically do:

var userRepo = new UserRepository();
var activeUsers = userRepo.FindActiveUsers();
foreach (var user in activeUsers)
{
    // do something with user
    var audit = new Audit();
    audit.Date = DateTime.Now;
    audit.UserID = user.ID;
    user.Audits.Add(audit);
    userRepo.Save();
}

To re-use the already open DataContext? What would you do in situations where you open a high-level datacontext and then had to do some processing low level, should I pass the userRepo down or should I create a separate Repository?

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和我恋爱吧 2024-08-22 23:19:07

要访问其他表中的字段，您需要保持 DataContext 处于活动状态。另外，不要直接调用dispose，使用using关键字。

using (MyDataContext context = new MyDataContext()) // DB connection established.
{
    MyTableRecord myEntity = myDataContext.Table.FindEntity(12345); // retrieve entity

    foreach (var record in MyEntity.RelatedTable)
    {
        ...
    }
}

To access fields in other tables you will need to keep the DataContext alive. Also, don't call dispose directly, use the using keyword.

using (MyDataContext context = new MyDataContext()) // DB connection established.
{
    MyTableRecord myEntity = myDataContext.Table.FindEntity(12345); // retrieve entity

    foreach (var record in MyEntity.RelatedTable)
    {
        ...
    }
}

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