C# Issue while importing Excel sheets - c#

I've searched the internet for this and couldn't really find a question like it.I am coding an application that takes data from Excel and view it.
All of my tests were correct, but suddenly I found that Importing a column that contains set of numbers in a row then letters will result in not showing the fields that contain those letters at all
PathConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + FilePath + ";Extended Properties=\"Excel 8.0;HDR=Yes;\";";
OleDbConnection conn = new OleDbConnection(PathConn);
System.Data.DataTable dtSchema = new System.Data.DataTable();
conn.Open();
dtSchema = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
string Sheet1 = dtSchema.Rows[0].Field<string>("TABLE_NAME");
conn.Close();
OleDbDataAdapter myDataAdapter = new OleDbDataAdapter("Select * from [" + Sheet1 + "]", conn);
DataSet ds = new DataSet();
myDataAdapter.Fill(ds);
the first dataset is the regular result
7841
7847s
2344
2262
7738
JD32916
JD329161
JD318161
JD31716
JD7643
JD21116
7194
the second dataset is the problematic result (notice that I removed the 's' from "7847s")
7841
7847
2344
2262
7738
7194
as you can see, all the fields with letters in them just disappeared,
it only happens where there are 5 or more consecutive fields with no letters in them. example (2nd number from the top contains 's' to prevent that error from happening)

Use IMEX=1 in your extended properties to treat all columns as text values. Without it, the Jet provider will infer a data type based on whatever type the majority of the values in that column is, which may not be correct.
Secondly, since your data does not have a header row, you should use HDR=NO in your extended properties as well.

Related

Search Excel sheet from ASP.NET C#

UPDATE:
I have found that this code works! it searches the Excel sheet and only outputs the data I need.
But can anyone explain to me why this works? how does it know that the first line in the spreadsheet is the "index"??
//Coneection String by default empty
string ConStr = "";
//connection string for that file which extantion is .xlsx
ConStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + "C:\\TestExcel.xlsx" + ";Extended Properties='Excel 12.0 XML;HDR=YES;';";
//making query
string query = "SELECT * FROM [lol$] where ID='i2200'";
//Providing connection
OleDbConnection conn = new OleDbConnection(ConStr);
//checking that connection state is closed or not if closed the
//open the connection
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
//create command object
OleDbCommand cmd = new OleDbCommand(query, conn);
// create a data adapter and get the data into dataadapter
OleDbDataAdapter da = new OleDbDataAdapter(cmd);
DataSet ds = new DataSet();
//fill the Excel data to data set
da.Fill(ds);
foreach (DataRow row in ds.Tables[0].Rows)
{
lblud.Text = "" + row["Hylde"];
}
OLD
I have been trying to do this for several hours now but no matter what i try, I don't end up with the result i want.
So now im "starting from scratch" again. See if I have approached this incorretly.
Question:
I wan't to create a ASPX website that can search my excel sheet for specific data.
Something like Select * from [Sheet1$] where Column A = i2200
then display only Column B and C from that specific row into a Label / two labels.
See picture here: http://itguruen.dk/EXCEL.png
Does anyone have a simple way of doing this?
Thanks in advance!
Jasper
Have you thought about importing the Excel Spreadsheet into a DataTable, and then analyse that DataTable to populate your labels? You can perform SQL queries on DataTables, so you'll be able to extract the exact data you require quite easily (the hardest part will be importing the Excel Spreadsheet into the DataTable).
There's a very detailed report on this process here: http://www.aspsnippets.com/Articles/Read-and-Import-Excel-File-into-DataSet-or-DataTable-using-C-and-VBNet-in-ASPNet.aspx
Update the post so you can see the solution.
Allthough I dont really know why this works??

Reading from excel file using oledb - empty strings

I'm using oledb to read from excel file.
DataTable sheet1 = new DataTable();
string excelCS = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";" + "Extended Properties=\"Excel 12.0 Xml;HDR=NO;TypeGuessRows=0;ImportMixedTypes=Text\"";
using (OleDbConnection connection = new OleDbConnection(excelCS))
{
connection.Open();
string selectSql = #"SELECT * FROM [Sheet1$]";
using (OleDbDataAdapter adapter = new OleDbDataAdapter(selectSql, connection))
{
adapter.Fill(sheet1);
}
connection.Close();
}
But there is a problem with some cells of the file.
For some cells I get an empty value instead of text. I tried to put some other text into these cells but it didn't work - I'm still getting empty strings.
But after deleting the column and inserting again my application get the right value of cell. Important is that the problem is not with all cells in the column.
Is this a problem with cell format or something? This excel file will be generated by another system so I won't be able to modify it manually.
Has anybody any sugestions what's wrong and what can I do?
Use IMEX = 1 at the end of your connection string. That will fix your problem.
To always use IMEX=1 is a safer way to retrieve data for mixed data
columns. .."
Remember that, sometimes there are some errors involved using IMEX while you're using Update rather than Selecting.
using this method convert Execel to Dataset without Empty String in c#
public static DataSet ConvertExcelToDataTable(string FileName)
{
DataSet ds = new DataSet();
string strConn = "";
strConn = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + FileName + ";Extended Properties=\"Excel 8.0; HDR=YES; IMEX=1;\"";
OleDbDataAdapter da = new OleDbDataAdapter
("SELECT * FROM [Sheet1$]", strConn);
da.Fill(ds);
return ds;
}
it will return dataset.
I had this issue. What I found was that on the cells that returned blank values the data looked like strings, but the rest of the data looked like numbers, so excel stored the strings in a different place as the numbers. I changed the column format to text and all the data was picked up.
This thread might help with changing the format: Format an Excel column (or cell) as Text in C#?

Reading an Excel file with C# causes OleDbException to be thrown

The message says
The Microsoft Access database engine could not find the object
'Sheet1$'. Make sure the object exists and that you spell its name and
the path name correctly. If 'Sheet1$' is not a local object, check
your network connection or contact the server administrator.
The name of the sheet in the Worksheet is "Sheet1"
string connectionString = String.Format(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=""Excel 12.0 Xml;HDR=YES"";", fileName);
string query = String.Format("SELECT [columnName1],[columnName2],[columnName3] from [{0}]", "Sheet1$");
OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, connectionString);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet);
DataTable YourTable = dataSet.Tables[0];
listBox1.DataSource = YourTable.Columns["ColumnName1"];
This works for me:
string filename = #"C:\Book1.xlsm";
string connectionString = String.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=YES\";", filename);
string query = String.Format("SELECT * from [{0}$]", "Sheet1");
OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, connectionString);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet);
DataTable YourTable = dataSet.Tables[0];
*NOTE: * If your data does not have headers to make HDR=NO
Also noticed that in your question you used
[columnName1],[columnName2],[columnName3]
for your columns to select. Please remember these should be the value(s) of the first cell in the column(s) that you would like to grab.
To get column E Use:
string connectionString = String.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=NO\";", filename);
string query = String.Format("SELECT [F5] from [{0}$]", "Sheet1");
Replace 5 With any other column number you need so
F1 = A
F2 = B
F3 = C
and so on.
The Error you are getting could be because you have the file open and active.
OR you are pointing at the wrong file (Remember you have to include full file path in the filename string. and make sure the sheet is correct. Alos take notice to the fact the i include the $ in my string not in my parameter so rememer to only put just the name of the sheet you are trying to get. If you are still having trouble supply me with the FULL file name for the worksheet you are using i.e. C:\Book1.xlsm and the sheet you are trying to get data from.
Please put square brackets around Sheet1.
So your query is: select * from [Sheet1$]

Importing "0000" or "0030" into DataTable

I am importing values like 0000,0002,0023,0034 from a text file. However, the table shows them as 0, 2, 23, 34. Does anyone know why it is removing the leading zeros?
Here is my code:
private DataTable ImportTabFile()
{
string dataSourcePath = #"C:\Documents and Settings\agordon\Desktop";
string dataFileName = "ACTIVITYEX.txt";
string connString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dataSourcePath + #";Extended Properties=""text;HDR=No;FMT=Delimited""";
OleDbConnection conn = new OleDbConnection(connString);
OleDbCommand cmd = conn.CreateCommand();
cmd.CommandText = String.Format("SELECT * FROM [{0}]", dataFileName);
DataSet ds = new DataSet();
OleDbDataAdapter da = new OleDbDataAdapter(cmd);
da.Fill(ds);
return ds.Tables[0];
}
How can I keep the leading zeroes during the import?
here is what my schema file looks like:
[ACTIVITYEX.txt]
Format=TabDelimited
ColNameHeader=False
Col13=ErrorCode Text
JET will infer types based on the first row. It is probably inferring your fields are INT because 0000 can be converted to a number. As mentioned above, leading zeroes are useless.
You can use schema.ini to explicitly define the column types. As noted in the comments above, you need to specify each column as per the documentation:
You must specify each column by number and designate the column name, data type, and width for fixed-length files.
Alternatively this article has some information on controlling how the types are inferred.

Read data from Excel

I have been trying to read data from an excel file. It has been successful, but I enountered a problem. Whenever the format of the cell and the data entered in the cell is not matching then I get empty data
e.g
If the data cell is formatted as Date - dd/mm/yyyy, and the user enters 13/17/2011, the as the date format and the date entered is contradictory so the excel gives me entirely empty cell. Only if the cell format is text I get the data as entered.
Why is the excel file giving me empty cell in case the entered date format is not complying with the cell format set?
This is the code that reads the excel data
if(fileEXT.Equals(".xls"))
{
oledbConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+Server.MapPath("../Portal_Docs/UploadDocs/"+filename+"")+";Extended Properties=Excel 8.0");
}
else if(fileEXT.Equals(".xlsx"))
{
oledbConn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source="+Server.MapPath("../Portal_Docs/UploadDocs/"+filename+"")+";Extended Properties=\"Excel 12.0;HDR=YES;\"");
}
else if(fileEXT.Equals(".xlsm"))
{
oledbConn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source="+Server.MapPath("../Portal_Docs/UploadDocs/"+filename+"")+";Extended Properties=Excel 12.0 Macro");
}
oledbConn.Open();
OleDbCommand cmd = new OleDbCommand("SELECT * FROM [Sheet1$]", oledbConn);
OleDbDataAdapter oleda = new OleDbDataAdapter();
oleda.SelectCommand = cmd;
DataSet ds = new DataSet();
oleda.Fill(ds,"LocationDetails");
You can change your connection string to
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+Server.MapPath("../Portal_Docs/UploadDocs/"+filename+"")+";Extended Properties=Excel 8.0;HDR=Yes;IMEX=1"
HDR=Yes;IMEX=1
tells OldDb driver that data at columns in defferent format.
Instead of OLEDB, I would suggest using EPPLus library to handle your excel files.It is very easy and comprehensive. Nuget package is also available for the same. http://nuget.org/packages/EPPlus

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