小编Elh*_*far的帖子

我有一个大表,想知道是否可以提高查询性能.

allDocumentsWithPersianMonth有25000000记录

    var normalDocuments = allDocumentsWithPersianMonth.Where(x => x.DocumentTypeId != 8 && x.DocumentTypeId != 9);
    var debitOpening = allDocumentsWithPersianMonth.Where(x => x.DocumentTypeId == 8);
    var creditOpening = allDocumentsWithPersianMonth.Where(x => x.DocumentTypeId == 8);
    var debitClosing = allDocumentsWithPersianMonth.Where(x => x.DocumentTypeId == 9);
    var creditClosing = allDocumentsWithPersianMonth.Where(x => x.DocumentTypeId == 9);

    return allDocumentsWithPersianMonth
        .GroupBy(x => new { x.DetailId, x.DetailCode, x.DetailDescription, x.PersianMonth })
        .Select(g => new AccountsAgingViewModel
        {
            DetailId = g.Key.DetailId,
            DetailCode = g.Key.DetailCode,
            DetailDescription = g.Key.DetailDescription,
            FarvardinDebit = normalDocuments.Where(x => x.DetailId == …

考虑像这样的表

   debit    credit  code
-----------------------------
    0       10      5
    5       0       3
    0       11      2
    0       15      1
    7       0       6
    6       0       2
    5       0       1

我需要生成一个这样的结果集,首先是借记,然后按代码列排序:

debit   credit  code
----------------------------
5       0       1
6       0       2
5       0       3
7       0       6
0       15      1
0       11      2
0       10      5

我想删除具有以下条件的所有外键.

SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
WHERE TABLE_NAME IN ('Table1', 'Table2')
  AND CONSTRAINT_NAME LIKE '%FK__%__DL%'

我能够在 SSMS 中执行该函数，它返回预期值

SELECT *
FROM dbo.AccDocumentHeaders
WHERE TypeDocumentId = 1
    AND dbo.MiladiToShamsi(DocumentDate, 'Saal') = 1395

但在实体框架上，我在尝试执行以下命令时收到此错误：

var q= "SELECT *  
        FROM dbo.AccDocumentHeaders 
        WHERE TypeDocumentId=1 
           AND [dbo].MiladiToShamsi(DocumentDate,'Saal')=1395 ";

var result = _uow.AccDocumentHeaders.SqlQuery(q).ToList();

找不到列“dbo”或用户定义函数找不到列“dbo”或用户定义函数或聚合“dbo.MiladiToShamsi”，或者名称不明确

任何帮助将不胜感激。

我需要提供一个WPF GridView,其中一列是a Combobox,用户可以从列表中选择一个值或输入一个新值,所以我设置IsComboBoxEditable为true但问题是如果用户键入的值不在ItemsSourceText中Combobox失去焦点时空白.

注意:我不希望在键入新值时,将此值添加到ItemsSource.我只需要将它的string值保存在与它有界的行中.

我还需要DropDownOpened事件来填充它的ItemsSource.

这是我的代码:

<telerik:GridViewDataColumn Header="Description">
    <telerik:GridViewDataColumn.CellTemplate>
        <DataTemplate>
            <telerik:RadComboBox IsEditable="True" ItemsSource="{Binding Descriptions}" Text="{Binding Description1,Mode=TwoWay}" DropDownOpened="descriptionRadComboBox_DropDownOpened"/>
        </DataTemplate>
    </telerik:GridViewDataColumn.CellTemplate>
</telerik:GridViewDataColumn>

Description1是string属性,Descriptions是string运行时填充的列表.(当DropDownOpened事件发生时)

我有enum这样的:

public enum DLTypeEnum
{
    Others = 1, People = 2, Company = 4,
}

我有这样一个属性ViewModel:

private DLTypeEnum _DLType;
public DLTypeEnum DLType
{
    get { return _DLType; }
    set { SetProperty(ref _DLType, value); }
}

这是我的xaml:

<WrapPanel  Grid.Row="3" Grid.Column="1">
    <WrapPanel.Resources>
        <Converter:EnumToBoolConverter x:Key="EnumToBooleanConverter" />
    </WrapPanel.Resources>
    <RadioButton GroupName="DLType" IsChecked="{Binding Path=DLType,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource EnumToBooleanConverter}, ConverterParameter={x:Static dlAccount:DLTypeEnum.Others}}"/>
    <RadioButton GroupName="DLType" IsChecked="{Binding Path=DLType,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource EnumToBooleanConverter}, ConverterParameter={x:Static dlAccount:DLTypeEnum.People}}"/>
    <RadioButton GroupName="DLType" IsChecked="{Binding Path=DLType,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, Converter={StaticResource EnumToBooleanConverter}, ConverterParameter={x:Static dlAccount:DLTypeEnum.Company}}"/>
 </WrapPanel>

而这个转换器:

 public class EnumToBoolConverter:IValueConverter
    { …

我有WindowTable以及以下数据:

SELECT  Id FROM WindowTable WHERE OwnerRef=12

 Id
----
25000
25001
25003
25004
25005
25006
25007
25008

我想在ActionTable中为每个WindowTable行插入3行像这样:

Id    WindowsRef     ActionName     ActionName2     

-----------------------------------------------
1       25000          'Add'          'E'
2       25000          'DELETE'       'H'
3       25000          'UPDATE'       'B'  
4       25001          'ADD'          'E'
5       25001          'DELETE'       'H' 
6       25001          'Update'       'B'
.         .              .
.         .              .

ActionTable.Id不是标识列

我在C＃中有此代码

double result = 480 - 460.8;

为什么结果是19.199999999999989而不是19.2？