从DataTable获取记录 [英] Get Records from DataTable

问题描述

我有DataTable有DataTime类型列，我想从Datetime列字段的小时基础上从表中选择记录。



想要相同的Sql Query结果从TableName中选择ColumnName，其中datepart（HOUR，ColumName）= 09



09是小时值。



如果有任何想法请分享。

I have DataTable having DataTime type column, i want to select records from table on hour basic from Datetime column field.

want same result of Sql Query " select ColumnName from TableName where datepart(HOUR,ColumName)=09"

09 is hour value.

If have any idea please share.

推荐答案

你需要引用System.Data.DataSetExtensions程序集并使用System.Data命名空间。

You need to reference the System.Data.DataSetExtensions assembly and use the System.Data namespace.

dt =dt.AsEnumerable()
       .Where(r=>r.Field<datetime>("DateCol").Month ==9)
       .CopyToDataTable();

并阅读.NET Framework 3.5的文档

从查询创建DataTable（LINQ到DataSet） [ ^ ]

And read the documentation for .NET Framework 3.5
Creating a DataTable From a Query (LINQ to DataSet)[^]

below is sample code from above reference 
// Bind the System.Windows.Forms.DataGridView object 
// to the System.Windows.Forms.BindingSource object.
dataGridView.DataSource = bindingSource;

// Fill the DataSet.
DataSet ds = new DataSet();
ds.Locale = CultureInfo.InvariantCulture;
FillDataSet(ds);

DataTable orders = ds.Tables["SalesOrderHeader"];

// Query the SalesOrderHeader table for orders placed  
// after August 8, 2001.
IEnumerable<DataRow> query =
    from order in orders.AsEnumerable()
    where order.Field<DateTime>("OrderDate") > new DateTime(2001, 8, 1)
    select order;

// Create a table from the query.
DataTable boundTable = query.CopyToDataTable<DataRow>();

// Bind the table to a System.Windows.Forms.BindingSource object,  
// which acts as a proxy for a System.Windows.Forms.DataGridView object.
bindingSource.DataSource = boundTable;

当我使用9作为值时，该查询对我来说非常有效。



09似乎表示您将数据存储为文本而非日期时间，在这种情况下，您将格式化为日期时间。

That query works perfectly well for me when I use 9 as the value.

09 seems to indicate you are storing the data as text and not datetime in which case you are screwed until you change the format to datetime.

这篇关于从DataTable获取记录的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！