实体框架 BuildContainsExpression 导致内部 .NET Framework 数据提供程序错误 1025。

Question

我正在尝试使以下LINQ查询针对数据库（3.5 SP1）正常工作：

var labelIds = new List<int> { 1, 2 };
var customersAggregatedTransactionsByType =
    (from transactions in context.TransactionSet
    from customers in context.CustomerSet
        .Where(LinqTools.BuildContainsExpression<Billing.Customer, int>(u => u.LabelId, labelIds))
    from accounts in context.AccountSet
    where customers == accounts.Customer
        && accounts.Id == transactions.Account.Id
        && transactions.DateTime >= fromDate && transactions.DateTime < toDate
    group transactions.Amount
    by new
    {
        UserAccountId = transactions.Account.Id,
        TransactionTypeId = transactions.TransactionTypeId,
        BaseAssetId = accounts.BaseAssetId
    } into customerTransactions
    select customerTransactions).ToList();

当我添加了Where(LinqTools.BuildContainsExpression<Billing.Customer, int>(u => u.LabelId, labelIds))后，我会得到以下异常：

System.InvalidOperationException: 内部 .NET Framework 数据提供程序错误 1025。

如果我删除Where(LinqTools.BuildContainsExpression<Billing.Customer, int>(u => u.LabelId, labelIds))就没问题了。

希望能得到任何帮助。

谢谢，Nir。

- nirpi

Answer 1

尝试：

        var labelIds = new List<int> { 1, 2 };
        var exp = LinqTools.BuildContainsExpression<Billing.Customer, int>(u => u.LabelId, labelIds);
        var customersAggregatedTransactionsByType =
             (from transactions in context.TransactionSet
              from customers in context.CustomerSet.Where(exp)
              from accounts in context.AccountSet
              where customers == accounts.Customer
                 && accounts.Id == transactions.Account.Id
                 && transactions.DateTime >= fromDate && transactions.DateTime < toDate
              group transactions.Amount
              by new
              {
                  UserAccountId = transactions.Account.Id,
                  TransactionTypeId = transactions.TransactionTypeId,
                  BaseAssetId = accounts.BaseAssetId
              } into customerTransactions
              select customerTransactions).ToList();

你想要查询结果，而不是对LinqTools.BuildContainsExpression方法本身的调用。

- Craig Stuntz

---

哦，你真是个天才！我在一个小时前开了一个类似的问题的悬赏，后来才发现了你的答案。请去那里领取你的悬赏吧。 - Shaul Behr

听起来很明显，但你是正确的，表达式必须在查询之外构建。 - Travis J