将列添加到memmory表中 [英] add column to in memmory table

问题描述

大家好我想知道是否有可能在内存数据表中添加一个标识列，以便更容易地编辑memroy数据我导入电子表格，并且我想在数据中添加一个标识列，其中增加了1到数据所以每行旁边都会有一个id号码，这是我的代码，百分之百的导入我只是不知道如何添加id列

Hi everyone i want to know if it is possible to add a identity column to an in memory datatable to make editing of the in memroy data easier I import an spreadsheet and i want to add a identity column to the data which increments with 1 to the data so there will be an id number next to each row here is my code it works hundred percent to import i just dont know how to add an id column

void ExportToGrid(String path)
        {
            OleDbConnection MyConnection = null;
            DataSet DtSet = null;
            OleDbDataAdapter MyCommand = null;
            String NewString = filename.Remove(filename.Length - 2, 2);
            string last = NewString[NewString.Length - 1].ToString();
            switch (last)
            {
                case "x":
                    //Connection for MS Excel 2003 .xls format
                    MyConnection = new OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; Data Source='" + path + "';Extended Properties='Excel 8.0;HDR=No;'");
                    break;
                case "l":
                    //Connection for .xslx 2007 format
                    MyConnection = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source='" + path + "';Extended Properties='Excel 12.0;HDR=No;'");  
                    break;
            }                             
            //Select your Excel file
          
            MyCommand = new System.Data.OleDb.OleDbDataAdapter("select * from [Sheet1$]", MyConnection);
            //Worksheet sheet = new Worksheet("Sheet1");
            //int LastRow = sheet.Cells.SpecialCells(XlCellType.xlCellTypeLastCell, Type.Missing).Row;
            DtSet = new System.Data.DataSet();
            //Bind all excel data in to data set
            MyCommand.Fill(DtSet, "[Sheet1$]");
            System.Data.DataTable dt = DtSet.Tables[0];
            ViewState["SelectedRecords"] = dt;
            MyConnection.Close();
            
            //Check datatable have records
            if (dt.Rows.Count > 0)
            {
                GridView2.DataSource = dt;
                GridView2.DataBind();
            }
            //Delete temporary Excel file from the Server path
            if (System.IO.File.Exists(path))
            {
                System.IO.File.Delete(path);
            }
            string expression1 = "F4 = ''";

            String valuesarr = String.Empty;
            for (int i = 0; i < dt.Rows.Count - 1; i++)
            {
                List<object> lst = dt.Rows[i].ItemArray.ToList();
                foreach (Object s in lst)
                {
                    valuesarr += s.ToString();                   
                }

                if (String.IsNullOrEmpty(valuesarr))
                    dt.Rows.RemoveAt(i);
            }
            DataRow[] foundRows = dt.Select(expression1);

            int CellCount = foundRows.Length;

            string expression2 = "F2 IS NULL";
            DataRow[] foundRows2 = dt.Select(expression2);

            int nameCount = foundRows2.Length;

            string expression3 = "F3 IS NULL";
            DataRow[] foundRows3 = dt.Select(expression3);

            int surnameCount = foundRows3.Length;
            tableImport.Visible = true;
        }

推荐答案

，MyConnection）;
// 工作表表=新工作表（Sheet1）;
// int LastRow = sheet.Cells.SpecialCells（XlCellType.xlCellTypeLastCell，Type.Missing）.Row;
DtSet = new System.Data.DataSet（）;
// 绑定所有Excel数据in to data set
MyCommand.Fill（DtSet， [Sheet1

", MyConnection); //Worksheet sheet = new Worksheet("Sheet1"); //int LastRow = sheet.Cells.SpecialCells(XlCellType.xlCellTypeLastCell, Type.Missing).Row; DtSet = new System.Data.DataSet(); //Bind all excel data in to data set MyCommand.Fill(DtSet, "[Sheet1

）;
System.Data.DataTable dt = DtSet.Tables [ 0 ];
ViewState [ SelectedRecords] = dt;
MyConnection。关（）;

// 检查数据表是否有记录
if （dt.Rows.Count > 0 ）
{
GridView2.DataSource = dt;
GridView2.DataBind（）;
}
// 从服务器路径中删除临时Excel文件
if （System.IO.File.Exists（path））
{
System.IO.File.Delete（path）;
}
string expression1 = F4 ='';

String valuesarr = String .Empty;
for （ int i = 0 ; i < dt.Rows.Count - 1 ; i ++）
{
List< object> lst = dt.Rows [i] .ItemArray.ToList（）;
foreach （对象 s lst）
{
valuesarr + = s.ToString（）;
}

if （ String .IsNullOrEmpty（valuesarr））
dt.Rows.RemoveAt（i）;
}
DataRow [] foundRows = dt.Select（expression1）;

int CellCount = foundRows.Length;

string expression2 = F2 IS NULL;
DataRow [] foundRows2 = dt.Select（expression2）;

int nameCount = foundRows2.Length;

string expression3 = F3 IS NULL;
DataRow [] foundRows3 = dt.Select（expression3）;

int surnameCount = foundRows3.Length;
tableImport.Visible = true ;
}

"); System.Data.DataTable dt = DtSet.Tables[0]; ViewState["SelectedRecords"] = dt; MyConnection.Close(); //Check datatable have records if (dt.Rows.Count > 0) { GridView2.DataSource = dt; GridView2.DataBind(); } //Delete temporary Excel file from the Server path if (System.IO.File.Exists(path)) { System.IO.File.Delete(path); } string expression1 = "F4 = ''"; String valuesarr = String.Empty; for (int i = 0; i < dt.Rows.Count - 1; i++) { List<object> lst = dt.Rows[i].ItemArray.ToList(); foreach (Object s in lst) { valuesarr += s.ToString(); } if (String.IsNullOrEmpty(valuesarr)) dt.Rows.RemoveAt(i); } DataRow[] foundRows = dt.Select(expression1); int CellCount = foundRows.Length; string expression2 = "F2 IS NULL"; DataRow[] foundRows2 = dt.Select(expression2); int nameCount = foundRows2.Length; string expression3 = "F3 IS NULL"; DataRow[] foundRows3 = dt.Select(expression3); int surnameCount = foundRows3.Length; tableImport.Visible = true; }

Hi Divan，



您可以在现有数据表中创建标识列按照以下步骤：



步骤1）创建一个标识栏

Hi Divan,

you can create Identity column in Existing Datatable in following Steps :

Step 1) Create an Identity Column

DataColumn IdentityCol = new DataColumn("ID");
IdentityCol.AutoIncrement = true;
IdentityCol.AutoIncrementSeed = 1;
IdentityCol.AutoIncrementStep = 1;

步骤2）将标识列添加到现有数据表

Step 2) Add Identity Column to Exisiting Datatable

//Assuming dt as Datatable 
dt.Columns.Add(IdentityCol);

步骤3）更新Exisitng DataColumn值

Step 3) Update Exisitng DataColumn Value

for(i=1; i<=dt.Rows.Count; i++)
{
dt.Rows[i-1]["ID"] = i;
}

<pre>


Now Identity Column will automatically Incremented, whenever new row gets added. 

Thanks! 
Yogendra Dubey

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