linq - 如何将 DataTable 转换为 IEnumerable>？

Question

我想将 DataTable 转换为 IEnumerable<>的 Dictionary<string, object> .我尝试了以下 LINQ 查询，

from DataRow row in ds.Tables[0].AsEnumerable()
let rowDictionary = new Dictionary<string, object>()
from DataColumn column in row.Table.Columns.Cast<DataColumn>()
select rowDictionary.Add(column.ColumnName, row[column]).ToArray();

但我收到以下错误:

error CS1943: An expression of type 
'System.Collections.Generic.IEnumerable<System.Data.DataColumn>' is not 
allowed in a subsequent from clause in a query expression with source type 
'System.Data.EnumerableRowCollection<AnonymousType#1>'.  Type inference 
failed in the call to 'SelectMany'.

我知道我可以用循环来强制执行此操作，但这似乎是我应该能够在 LINQ 中执行的操作。在此先感谢您的帮助!

Answer 1

我假设您想要的是每个行映射列到值的字典:

var dt = new DataTable();

var columns = dt.Columns.Cast<DataColumn>();
dt.AsEnumerable().Select(dataRow => columns.Select(column => 
                     new { Column = column.ColumnName, Value = dataRow[column] })
                 .ToDictionary(data => data.Column, data => data.Value));