Inserting a row into Excel Spreadsheet via C# and OleDb - c#

I need to programmatically insert a row into an Excel Spreadsheet multiple times. I need to actually insert a new row and not insert data, that is, I need to actually shift all other rows down by one.
I am currently using OleDB to insert the data itself like so:
//Note I have missed some code out for simplicities sake, this all works fine however
OleDbConnection oledbConn = null;
OleDbCommand cmd = null;
OleDbConnection = new OleDbConnection(connString);
OleDbConnection.Open();
string connString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0; \"", TargetFile);
sting InsertCommand = string.Format("INSERT INTO [{0}${1}:{1}] Values({2})", WorksheetName, Coord, valuestring);
cmd = new OleDbCommand(InsertCommand, oledbConn);
cmd.ExecuteNonQuery();
//close etc
I want to be able to insert a row in a similar fashion. Is this possible?

At a glance, you need to specify read write, the default is read only. Perhaps:
"Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:\Docs\Test.xls;" & _
"Mode=ReadWrite;Extended Properties=""Excel 8.0;HDR=No"""
At a second glance and re comments, I think Interop might be the best bet.

ipavlic is right, you will be better off using an external third-party library for this. There are several available. OfficeWriter is one example:
http://www.officewriter.com
Once you open a workbook with OfficeWriter, you can use this method on the Worksheet class to insert rows. It mimics Excel's behavior, including updating/stretching formulas and other updates:
public void InsertRows(int rowNumber, int rowCount)

Related

Storing a big Excel table into array with C#

I have an Excel table with about 50 columns and over 6000 rows.
I found the following solution to read the data:
https://coderwall.com/p/app3ya/read-excel-file-in-c
It uses Microsoft.Office.Interop.Excel to read the file.
Sadly, it is really slow. Reading a file with only 50 rows allready take about a minute. I never finished loading the 6000 row file.
I then thought about using csv, but the table contains , and ; so this won't be an option.
Can anyone suggest another method?
Apart from my comment-
Here is the method I use in order to read from an Excel file and into a table. You will need to have:
using Microsoft.Office.Interop; using statement, along with adding the correct Microsoft.Office.Interop.Excel reference to your project.
Method:
public DataTable ReadExcel(string fileName, string TableName)
{
DataTable dt = new DataTable();
OleDbConnection conn = new OleDbConnection(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + fileName + ";Extended Properties=\"Excel 8.0\"");
OleDbCommand cmd = new OleDbCommand("SELECT * FROM " + TableName, conn);
try
{
conn.Open();
OleDbDataReader reader = cmd.ExecuteReader();
while (!reader.IsClosed)
{
dt.Load(reader);
}
}
finally
{
conn.Close();
}
return dt;
}
Explanation:
fileName will be the file path to the Excel file you are wanting to read the data form.
TableName will be the Excel Sheet name you are wanting to read data from.
The reason it is written this way, is because C# will read it and treat the Excel file like a database, where instead of sheets, there are tables.
You may need to alter the OleDbConnection(#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + fileName + ";Extended Properties=\"Excel 8.0\"");
You can find the proper/correct Provider here: https://www.connectionstrings.com/excel/
If you're only going to read the Excel file, I suggest ExcelDataReader instead of the interop.

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 excel file in c#.net cell by cell

I'm new to c#.net
I have excel sheet and I want to import into database.
I want to read it cell by cell and want to insert value in database.
this.openFileDialog1.FileName = "*.xls";
DialogResult dr = this.openFileDialog1.ShowDialog();
if (dr == System.Windows.Forms.DialogResult.OK)
{
string path = openFileDialog1.FileName;
string connectionString = String.Format(#"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=""Excel 8.0;HDR=no;IMEX=1;""", openFileDialog1.FileName);
string query = String.Format("select * from [{0}$]", "Sheet3");
OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, connectionString);
DataSet dataSet = new DataSet();
dataAdapter.Fill(dataSet);
dataGridView1.DataSource = dataSet.Tables[0];
I assume that after you execute the code in your question, you can see the values within dataGridView1.
The actual reading from the excel sheet is done when calling dataAdapter.Fill. So, in your case, reading the cells comes down to indexing columns and rows in dataSet.Tables[0].
For example:
for (int row = 0; row < dataSet.Tables[0].Rows.Count; row++)
{
DataRow r = dataSet.Tables[0].Rows[row];
}
Accessing the cells in row r is trivial (like the sample above, just for cell).
EDIT
I forgot to describe the "insert the values into a database" part. I presume that the database is SQL Server (may be Express edition, too).
First: create a database connection. Instead of manually composing the connection string, use the SqlConnectionStringBuilder:
SqlConnectionStringBuilder csb = new SqlConnectionStringBuilder();
csb.DataSource = <your server instance, e.g. "localhost\sqlexpress">;
csb.InitialCatalog = <name of your database>;
csb.IntegratedSecurity = <true if you use integrated security, false otherwise>;
if (!csb.IntegratedSecurity)
{
csb.UserId = <User name>;
csb.Password = <Password>;
}
Then, create and open a new SqlConnection with the connection string:
using (SqlConnection conn = new SqlConnection(csb.ConnectionString))
{
conn.Open();
Iterate over all the values you want to insert and execute a respective insert command:
for (...)
{
SqlCommand cmd = new SqlCommand("INSERT INTO ... VALUES (#param1, ..., #paramn)", conn);
cmd.Parameters.AddWithValue("#param1", value1);
...
cmd.Parameters.AddWithValue("#paramn", valuen);
cmd.ExecuteNonQuery();
}
This closes the connection, as the using block ends:
}
And there you go. Alternatively, you could use a data adapter with a special insert-command. Then, inserting the values would come down to a one-liner, however, your database table must have the same structure as the Excel-sheet (respectively: as the data table you obtained in the code you posted.
Check out NPOI
http://npoi.codeplex.com/
It's the .NET version of Apache's POI Excel implementation. It'll easily do what you need it to do, and will help avoid some of the problems ( i.e. local copy of Excel, or worse, copy of Excel on the server ) that you'll face when using the Jet provider.

Writing to a blank excel sheet with ADO.NET

I am trying to use ADO.NET to connect to and write to an excel file. I have created a blank file with the default excel sheets (I have also tried with a custom sheet.)
For some reason I am unable to write a full row of data to the sheet. If I create a new sheet it works fine, however then I have too many sheets and I am unable to delete any sheets.
Is there something special you need to do to write a row of data to a blank sheet?
I try to do:
path= the path including my file.
connString = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;HDR=NO;\"", Server.MapPath(path));
dbCmd.CommandText = "Update [Sheet1$] Set F1 = 'Col1', F2 = 'Col2', F3 = 'Col3', F4 = 'Col4'";
dbCmd.ExecuteNonQuery();
Here's an example of creating a brand new spreadsheet, creating a sheet (Sheet1) and then inserting a row into that. Most of this example was based on a blog entry from David Hayden (great blog entry for this task, btw!!).
Also, you should check out this Microsoft KB article for reading/writing to Excel from ADO.NET -- it really goes into a lot of detail.
//Most of this code was from David Hayden's blog:
// http://www.davidhayden.com/blog/dave/archive/2006/05/26/2973.aspx
static void Main(string[] args)
{
string connectionString = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Temp\TestSO1.xls;Extended Properties=""Excel 8.0;HDR=NO;""";
DbProviderFactory factory =
DbProviderFactories.GetFactory("System.Data.OleDb");
using (DbConnection connection = factory.CreateConnection())
{
connection.ConnectionString = connectionString;
using (DbCommand command = connection.CreateCommand())
{
connection.Open(); //open the connection
//use the '$' notation after the sheet name to indicate that this is
// an existing sheet and not to actually create it. This basically defines
// the metadata for the insert statements that will follow.
// If the '$' notation is removed, then a new sheet is created named 'Sheet1'.
command.CommandText = "CREATE TABLE [Sheet1$] (F1 number, F2 char(255), F3 char(128))";
command.ExecuteNonQuery();
//now we insert the values into the existing sheet...no new sheet is added.
command.CommandText = "INSERT INTO [Sheet1$] (F1, F2, F3) VALUES(4,\"Tampa\",\"Florida\")";
command.ExecuteNonQuery();
//insert another row into the sheet...
command.CommandText = "INSERT INTO [Sheet1$] (F1, F2, F3) VALUES(5,\"Pittsburgh\",\"Pennsylvania\")";
command.ExecuteNonQuery();
}
}
}
The only problem I found is that even though the connection string states not to use headers, you still have to define column names for your sheet, and ADO.NET inserts a row when you create the sheet that has the row header names. I can't seem to find a way around that besides going in after I insert everything and removing the first row. Not very elegant.
Hope this helps!! Let me know if you have other questions.

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