如何读取特定的列值在数据集中 [英] How to read Specific colum values In dataset

问题描述

我需要以最佳方式从数据集中检索特定列值



我的数据集如

I need to retrieve the specific column values From dataset in best way

my dataset like

Country  State     City         PinCode
India	Andhra	   Vijayawada	520005
India	Andhra	   Rajamundry	533101
India	Andhra	   Vijayawada	520001
India	Telangan   Hyderabad	500018
India	Kerala	   Palakkad	    678001
India	Kerala	   Kottayam	    686001
India	Kerala	   Kollam	    691001
India	Telangana  Madhira	    507203
India	Telangana  Hyderabad	500033
India	Telangana  Warangal	    506002
India	Telangana  Khammam	    507111
India	Telangana  Hyderabad	500081
India	Karnataka  Banglore	    560005
India	Karnataka  Manglore	    575001
India	Karnataka  Mysore	    570001
India	Karnataka  Banglore	    560001
India	Gujarat	   Surat	    395003
India	Gujarat	   Vadodara	    391110
India	Gujarat	   Rajakot	    360001

i想要检索所有城市来自数据集的名称

如何在不重复的情况下阅读这些内容



在此先感谢

i want to retrieve all the city names From The dataset
how can i read those without repetition

Thanks In Advance

推荐答案

您好



您可以使用dataview来获取您的特定栏目

Hi

you can use dataview to get your specific column

DataView view = new DataView(dataset.Tables[0]);
DataTable cityColumn = view.ToTable(true, "City");
DataRow[] myRows = cityColumn.Select();


Now you can iterate your rows
Hope this helps

Thanks
Ankit

我会使用Linq，虽然它不那么容易 - 我找不到一步法...这些都没有经过测试或者甚至编译，它只是一个可能的方式的粗略概念

I would have used Linq, although its not 'that easy' - I couldnt find a single step method .. none of this has been tested or even compiled, its just a rough idea of a possible way

// Given :-
// a DataSet ds
// a Table In The DataSet "MyTable"
// a Column Within the Table With The Column Name ‘City’

DataTable myDataTable = ds.Tables["MyTable"];

// Build a Linq Query
// One Could Include Other Filter Conditions Here 
IEnumerable<DataRow> query =
    from myDataRow in myDataTable.AsEnumerable()
    select myDataRow;

// A List To Hold ALL the City Values (We filter this later)
List<String> Cities = New List<String>();

// This Executes The Linq Query - In This Case We just capture 
// The Value of the City Column 
foreach (DataRow dr in query)
{
    Cities.Add(dr.Field<string>("City"));
}

// Roughly the end condition 
List<String> filteredCityList = Cities.Distinct();

注意：这是从我的MacBook输入的，我要小心复制并粘贴它 - 重新输入它更好，看起来MacBook已经输入了一些奇怪的引用，例如

NB : This was entered from my MacBook, I'd be careful of copying and pasting it - retype it is better, it looks like the MacBook has entered some strange quotes for example

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