【发布时间】：2019-11-09 15:17:15
【问题描述】：
我正在尝试将两个导入的 CSV 文件合并并连接到一个数据表中。 C# 对我来说是新的，但我以前在 PS 和 KSH 中做过很多次类似的事情。
数据加载正常，并像两个单独的表一样输出到控制台，但我不知道如何使用主键（wID，UserID）作为连接条件来连接每个 ShowTable() 的结果。
我尝试return Table_SalesUserData; and return Table_WifiUserData; 给出[ 'Form1.CreateTableWifi()' returns void, a return keyword must not be followed by an object expression ] 错误。
我也尝试使用：DataSet setSalesWifi = new DataSet(); 但在Button1_Click() 中会引发[ System.ArgumentNullException: ''column' argument cannot be null. Parameter name: column' ] 错误。
我认为这是因为每个的 .Columns 超出了范围。
表的创建如下所示。它们由 GenericParser 加载（代码工作正常，很长，所以没有发布）它们是 InsertTableWifi(string srcFilePathWifi) 和 InsertTableSales(string srcFilePathSales)。
我想我可以在合并数据工作时输出它，只是不知道如何将它们加入到新的 DataTable 或 DataSet 中。
有没有一种简单的方法可以将数据与我拥有的数据合并？
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Text.RegularExpressions;
using GenericParsing;
namespace GenericParserv1._1._6
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
DataTable Table_SalesUserData = new DataTable("SalesUserData ");
DataTable Table_WifiUserData = new DataTable("WifiUserData ");
DataSet setSalesWifi = new DataSet();
public void CreateTableSales()
{
DataColumn[] colsSales ={
new DataColumn("UserID",typeof(String)),
new DataColumn("Alias",typeof(String)),
new DataColumn("UserType",typeof(String)),
new DataColumn("AccountStatus",typeof(String)),
new DataColumn("ChgPasswdNxtLogin",typeof(String)),
};
Table_SalesUserData.Columns.AddRange(colsSales);
Table_SalesUserData.PrimaryKey = new DataColumn[] { Table_SalesUserData.Columns["UserID"] };
setSalesWifi.Tables.Add(Table_SalesUserData);
//return Table_SalesUserData ;
}
public void CreateTableWifi()
{
DataColumn[] colsWifi ={
new DataColumn("wID",typeof(String)),
new DataColumn("username",typeof(String)),
new DataColumn("fname",typeof(String)),
new DataColumn("lastname",typeof(String)),
new DataColumn("email",typeof(String)),
new DataColumn("empid",typeof(String)),
new DataColumn("lastlogintime",typeof(String))
};
Table_WifiUserData.Columns.AddRange(colsWifi);
Table_WifiUserData.PrimaryKey = new DataColumn[] { Table_WifiUserData.Columns["wID"] };
setSalesWifi.Tables.Add(Table_WifiUserData);
//return Table_WifiUserData ;
}
public void CreateTableReport()
{
DataColumn[] colsMerge ={
new DataColumn("wID",typeof(String)),
new DataColumn("username",typeof(String)),
new DataColumn("fname",typeof(String)),
new DataColumn("lastname",typeof(String)),
new DataColumn("email",typeof(String)),
new DataColumn("empid",typeof(String)),
new DataColumn("lastlogintime",typeof(String)),
new DataColumn("UserID",typeof(String)),
new DataColumn("Alias",typeof(String)),
new DataColumn("UserType",typeof(String)),
new DataColumn("AccountStatus",typeof(String)),
new DataColumn("ChgPasswdNxtLogin",typeof(String)),
};
Table_MergeUserData.Columns.AddRange(colsMerge);
Table_MergeUserData.PrimaryKey = new DataColumn[] { Table_MergeUserData.Columns["wID"] };
}
private static void ShowTable(DataTable table)
{
foreach (DataColumn col in table.Columns)
{
Console.Write("{0,-14}", col.ColumnName);
}
Console.WriteLine();
foreach (DataRow row in table.Rows)
{
foreach (DataColumn col in table.Columns)
{
if (col.DataType.Equals(typeof(DateTime)))
Console.Write("{0,-14:d}", row[col]);
else if (col.DataType.Equals(typeof(Decimal)))
Console.Write("{0,-14:C}", row[col]);
else
Console.Write("{0,-14}", row[col]);
}
Console.WriteLine();
}
Console.WriteLine();
}
private void Button1_Click(object sender, EventArgs e)
{
string srcFilePathWifi = @"c:\WifiUserData.csv";
string srcFilePathSales = @"c:\SalesUserData.csv";
CreateTableSales();
InsertTableSales(srcFilePathSales);
CreateTableWifi();
InsertTableWifi(srcFilePathWifi);
ShowTable(Table_WifiUserData);
ShowTable(Table_SalesUserData);
// Set the relations between the tables and create the related constraint.
setSalesWifi.Relations.Add("Table_WifiUserData", Table_SalesUserData.Columns["wID"], Table_SalesUserData.Columns["UserID"], true);
}
}
}
WifiUserData.csv：
wID username fname lastname email empid lastlogintime
msmith marysmith mary smith marysmith@company.com10001 24/01/2019 14:00
jbloggs joebloggs joe bloggs joebloggs@company.com10002 10/01/2019 9:00
pgolightly petergolightlypeter golightly petergolightly@company.com10003 20/01/2019 17:00
rrabbit rogerrabbit roger rabbit rogerrabbit@company.com10004 1/02/2019 14:00
SalesUserData.csv：
UserID Alias UserType AccountStatus ChgPasswdNxtLogin
msmith mary smith Manager No No
jbloggs joe bloggs Standard No No
pgolightly peter golightlyJunior No No
rrabbit roger rabbit Standard No No
我的目标：
UserID Alias UserType AccountStatus ChgPasswdNxtLogin username fname lastname email empid lastlogintime
msmith mary smith Manager No No marysmith mary smith marysmith@company.com 10001 24/01/2019 14:00
jbloggs joe bloggs Standard No No joebloggs joe bloggs joebloggs@company.com 10002 10/01/2019 9:00
pgolightly peter golightly Junior No No petergolightly peter golightly petergolightly@company.com 10003 20/01/2019 17:00
rrabbit roger rabbit Standard No No rogerrabbit roger rabbit rogerrabbit@company.com 10004 1/02/2019 14:00
【问题讨论】：
标签： c# csv join merge datatable