how to use for loop to read csv file one at a time?

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C#

string todate = txtToDate1.Text;
                string fromtime = DropDownList2.SelectedItem.Text;
                string totime = DropDownList3.SelectedItem.Text;

                string fromdatetime = fromdate + "_" + fromtime;
                string todatetime = todate + "_" + totime;

            
                con.ConnectionString = constr;

                //create instance for command object 
                OleDbCommand cmd = new OleDbCommand();
               

                cmd.Connection = con;   
                // set your file name in the below query
                cmd.CommandText = "select * from " + fromdatetime + ".csv ";
               
                
  
                //Open Oledb Connection to read CSV file 
                con.Open(); 

                //Create one datatable to store data from CSV file
                DataTable dt = new DataTable();

                // Load Data into the datatable 
                dt.Load(cmd.ExecuteReader());

string fromdatetime is something like 12162013_0730.csv and string todatetime is something like 12162013_0930.csv...how can i use for loop to read the file in between the fromdatetime todatetime... read 12162013_0730.csv ,12162013_0830.csv,12162013_0930.csv, one file at a time.

Posted 29-Dec-13 18:34pm

acing wei

Updated 29-Dec-13 19:05pm

Karthik_Mahalingam

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Karthik_Mahalingam · Accepted Answer · 2013-12-29T19:18:00

Solution 1

Hi This might help you..

C#

string strfrom = "12162013_0730";
        string strto = "12162013_1030";

       var from =  DateTime.ParseExact(strfrom, "MMddyyyy_hhmm", CultureInfo.InvariantCulture);
       var to = DateTime.ParseExact(strto, "MMddyyyy_hhmm", CultureInfo.InvariantCulture);
       double interval  = 60;
       List<string> lstDateString = new List<string>();
       lstDateString.Add(strfrom);
       while (from.AddMinutes(interval) != to)
       {

           lstDateString.Add(from.AddMinutes(interval).ToString("MMddyyyy_hhmm"));
           interval = interval + 60;
       }
       lstDateString.Add(strto);

       foreach (string datestring in lstDateString)
       {
           string csv = datestring + ".csv";
           // your coding here..
       }

Posted 29-Dec-13 19:18pm

Karthik_Mahalingam

Comments

Karthik_Mahalingam 30-Dec-13 3:39am

can you please explain more..
so that i can give u some suggestion..

acing wei 30-Dec-13 4:05am

okay.. the 'for each' loop it works well in reading that 4 csv files in one time which is 0730.csv,0830.csv,0930csv,and 1030.csv..in the cmd.command i count the pass value .however the gridview will only show the last csv "pass value" table which is 1030.csv...can it show four different table of "pass value" instead of the last one only..can i store the value each time it loops.....

Karthik_Mahalingam 30-Dec-13 4:12am

ofcourse it will show only the last value. since you are looping it..

in grid u need to show all 4 datatable combined ??

acing wei 30-Dec-13 4:19am

can it be looping first time then store the value, looping second time store the value and in the end got 4 value ... yes...my grid/mychart need to show like: at0730 how many pass, 0830 how many pass...something like that ... can it be done?

Karthik_Mahalingam 30-Dec-13 4:22am

you can do one thing.
in the loop. u store all the tables in a dataset..
and use the dataset for binding in grid. as per your need..

acing wei 30-Dec-13 4:35am

if i using dataset...how to actually read it per 0730,0830...isnt it will bind it only in one table?... can guide me a little bit? thank you...

Karthik_Mahalingam 30-Dec-13 4:40am

combine all the datatable to a single table or a list and assign it to the gridview..

Karthik_Mahalingam 30-Dec-13 4:40am

how many columns do you have ?

acing wei 30-Dec-13 4:44am

it will be 4 columns , for 0730 to 1030...but it depends if 0730 to 0930 it will be 3 columns..

acing wei 30-Dec-13 4:47am

DataTable dt = new DataTable();
DataTable1 dt = new DataTable();
DataTable2 dt = new DataTable();
// Load Data into the datatable
dt.Load(cmd.ExecuteReader());
dt1.Load(cmd.ExecuteReader());
dt2.Load(cmd.ExecuteReader());
is it like this ?

Karthik_Mahalingam 30-Dec-13 4:59am

do one thing..
insted of table.. use list to combine all 4 tables..

Karthik_Mahalingam 30-Dec-13 5:00am

post your column names..
i wil show you how to add data to the list...

acing wei 30-Dec-13 5:00am

can you guide me with a link?... im stuck...

Karthik_Mahalingam 30-Dec-13 5:05am

List<TableList> lstData = new List<TableList>(); // declare this line outside the loop.

dt.Load(cmd.ExecuteReader());
foreach (DataRow row in dt.Rows)
{
lstData.Add(new TableList() { Column1 = row[0] + "", Column2 = row[1] + "", Column3 = row[2] + "" });
}

// assign the lstData to the gridview..

acing wei 30-Dec-13 5:03am

you mean the one in 0730 csv file....or the column that i want to create??... process, product family, status,

Karthik_Mahalingam 30-Dec-13 5:07am

try this code..

{
List<TableList> lstData = new List<TableList>(); // declare this line outside the loop.

DataTable dt = new DataTable(); // dt.Load(cmd.ExecuteReader());
foreach (DataRow row in dt.Rows)
{
lstData.Add(new TableList() { process = row["process"] + "", product_family = row["product family"] + "", status = row["status"] + "" });
}

// assign the lstData to the gridview..

}

// declare this class outside the function..
class TableList
{

public string process { get; set; }
public string product_family { get; set; }
public string status { get; set; }
}

acing wei 30-Dec-13 21:48pm

Yes it works...all the data is in one datatable...how bout if my 'status column' inside got pass and fail...can i get another table to list out how many pass and fail?

Karthik_Mahalingam 30-Dec-13 23:28pm

you want to show only the count of pass / fail ??

acing wei 30-Dec-13 23:34pm

Karthik_Mahalingam 31-Dec-13 1:36am

is this grid or something?

acing wei 31-Dec-13 2:34am

yes its in grid....like above... is it possible to do that?

acing wei 31-Dec-13 2:39am

instead of showing the whole table , i want to show it in column of 0730 ,how many pass...0830 how many pass? it will count and show it in different column ...

acing wei 31-Dec-13 7:12am

mr karthik, can guide me with my problem?..

Karthik_Mahalingam 31-Dec-13 12:33pm

pls provide sample format of output, so that i can give suggestion on that..

acing wei 31-Dec-13 23:43pm

0730|0830|0930|
| | |
| | |
| | |
this is the sample output gridview...
1)inside the table is the count of "how many pass"..
2)how many pass is counted from the "status" column from the file.
3)the header is the "time' of different file that read from the for loop...

acing wei 2-Jan-14 1:03am

Loop for one DataTable and count that column store in a Variable.
Then go for next, count the same column and store in another variable and so on for other DataTables.

Then sum all the variable counts. You now have the total count.

Create a DataTable and make columns as you need and show these data under appropriate columns.
so this is what i suppose to do right? can help me one more round with example mr karthik?

Karthik_Mahalingam 2-Jan-14 1:05am

ok , pls wait for some time...

acing wei 2-Jan-14 1:10am

sorry, i will wait...
because i can understand your code and you really help me a lot.
thanks again mr karthik..

Karthik_Mahalingam 2-Jan-14 2:00am

you need only count ?

acing wei 2-Jan-14 2:06am

yes counting pass and fail

how to use for loop to read csv file one at a time?

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