System.InvalidOperationException: LINQ 表达式 'GroupByShaperExpression:

Question

我尝试获取特定位置项目的摘要。我尝试对它们进行分组，因为一个项目可以在特定位置多次出现，并获取该项目的摘要 item.It 可以很好地与 ITEMID 和 REMAIN 一起使用，但是当我尝试访问 Description 时它失败了我的命令看起来像这样

var items1 = await _context.Set<Comitemtran>()
    .Include(c => c.Bzitem)?
    .Include(c => c.Bzchopp)?
    .Include(c => c.Bzitemlot)?
    .Include(c => c.Bzstoreplace)?
    .Where(c => c.Bzstoreplaceid == placecode).GroupBy(c => c.Bzitemid).Select(group => new ItemTransView
    {
        BZITEMID = group.Key,
        BZDESC = group.Where(c => c.Bzitemid == group.Key).FirstOrDefault().Bzitem.Bzdesc,


        BZREMAIN = group.Sum(s => s.Bzquantity)
    }).ToListAsync();

当我执行它时，我收到邮递员的回复：

System.InvalidOperationException: The LINQ expression 'GroupByShaperExpression: KeySelector: c.BZITEMID, ElementSelector:EntityShaperExpression: EntityType: Comitemtran ValueBufferExpression: ProjectionBindingExpression: EmptyProjectionMember IsNullable: False .Select(s => s.Bzitem.Bzdesc) .First()' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'.

Answer 1

将 Description 添加到分组键。在这种情况下，查询将被翻译成 SQL

var items1 = await _context.Set<Comitemtran>()
    .Where(c => c.Bzstoreplaceid == placecode)
    .GroupBy(c => new { c.Bzitemid, c.Bzitem.Bzdesc })
    .Select(group => new ItemTransView
    {
        BZITEMID = group.Key.Bzitemid,
        BZDESC = group.Key.Bzdesc,
        BZREMAIN = group.Sum(s => s.Bzquantity)
    })
    .ToListAsync();

请注意，Include 后跟 Select 时会被忽略。

System.InvalidOperationException: LINQ 表达式 'GroupByShaperExpression:

System.InvalidOperationException: The LINQ expression 'GroupByShaperExpression:

.net

c#

linq