ds.Tables [0] .Select()代表什么 [英] What does ds.Tables[0].Select() represents

问题描述

博士到这里来.

DataRow[] dr = objds.Tables[0].Select("ProcessName = '" + tnProcName.Text + "'");

我正在获取dr {System.Data.DataRow [4]}，而不是一行.

I am getting dr{System.Data.DataRow[4]} and not the line individually.

博士现在由行列表组成.我该如何比较数据行中存在的列.

In dr now consists of list of rows.How can i compare the column present in data row.

推荐答案

它返回一个DataRow数组，该数组与Select方法的第一个参数表示的选择条件匹配

It returns an array of DataRow that match the selection criteria expressed by the first parameter of the Select method

DataRow[] dr = objds.Tables[0].Select("ProcessName = '" + tnProcName.Text + "'");
foreach(DataRow r in dr)
{
   string procName = r["ProcessName"].ToString();
   treeView1.Nodes.Add(procName);

}

Select具有四个重载以微调结果

Select has four overloads to fine tune the results

DataTable.Select(); // return all (same as dataTable.Rows)
DataTable.Select(filter); //The above one
DataTable.Select(filter, sort) //Filtered and/or sorted
DataTable.Select(filter, sort, rowstate) // Filtered and/or sorted and/or in a particular state

此处MSDN文档

可能不是您的情况，但是请记住，如果expression参数具有单引号，那么您需要将其加倍以避免在计算表达式时出现语法错误

Probably it is not your case, but keep in mind that if the expression parameter has a single quote then you need to double it to avoid a syntax error when the expression is evaluated

DataRow[] dr = objds.Tables[0].Select("ProcessName = '" + 
               tnProcName.Text.Replace("'", "''") + "'");

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