I'm reading an XLSX (Microsoft Excel XML file) using the Excel Data Reader from http://exceldatareader.codeplex.com/ and am having a problem with missing data. Data which is in the source Excel spreadsheet is missing from the data set returned by the library.
Here's a bit more detail of what I'm doing:
Created a simple test spreadsheet in Excel with one sheet, a header row and two data rows. Save and close Excel.
Open the file and pass the stream into the CreateOpenXmlReader() method and get back an IExcelDataReader.
Call the AsDataSet() method on the IExcelDataReader and get back a DataSet.
Get the ItemArray from row 1 of table 0.
Loop through the ItemArray. Discovered there is data missing (i.e. there are System.DBNull members where I expected System.string members).
Here's a bit more analysis...
I debugged the code and looked inside the ExcelDataReader object model. Found a non-public string array called "SST" which appears to contain the data from the spreadsheet as a single linear (one-dimensional) array.
On closer inspection, I found that the data I was looking for was also missing from this array. In this raw data, the member does not exist at all.
My guess is that for some reason the parser is not picking up the data from the OOXML and concluding that the cell is empty. Looking at the OOXML itself, the data seems to be split across the sharedStrings.xml and sheet1.xml files, so perhaps the parser is having a tough time putting all this together.
Saving the file in binary format (Excel 97 to 2003) and reading that in solves the problem so on the surface that seems to confirm my suspicion is with reading the OOXML format.
Suggestions?
As a stop gap I'm converting all files to binary format, but that seems like a kludge. Is there some way to get my OOXML formatted Excel files to read in properly with Excel Data Reader?
To retrieve an Excel spreadsheet (.xlsx) and load it into a DataSet, you don't need to mess with XML readers or a separate library like Excel Data Reader. The code for reading an entire spreadsheet into a DataSet is pretty simple when using the normal OleDb functions in .NET:
Sub readInMyExcelFile
Dim xlsFile as string = "myexcelfile"
Dim conStr As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & xlsFile & ";Extended Properties=""Excel 12.0 Xml;HDR=YES"""
Dim dtSheets As New DataTable
Dim tmp As String
Dim sqlText as Sting
Using cn As New OleDbConnection(conStr)
cn.Open()
dtSheets = cn.GetSchema("Tables")
End Using
//Dataset for the spreadsheet
Dim ds as New DataSet
/Loop through the names of all the worksheets in the file.
For Each rw as DataRow in dtSheets.Rows
tmp = rw("TABLE_NAME")
tmp = "[" & tmp & "]"
Dim dt as New DataTable
Using cn as New OleDbConnection(conStr)
cn.Open
/Retrieve all the records from the worksheet.
sqlText = "SELECT * FROM " & tblName
Dim adp As New OleDbDataAdapter(sqlText, cn)
/Fill the data table with the all the data.
adp.Fill(dt)
End Using
ds.Tables.Add(dt)
Next
End Sub
It seems there is a bug in Excel Data Reader (it is first time I have heard about it). Do you have to use it? If not, EPPlus would be a better choice.
excel datareader from codeplex is used for reading data from the excel file directly on web application without any sort of caching on the server.the above code only stands when we can store the excel file somewhere.I have faced similar problems with exceldatareader where some of the data are missing.Most importanly i coludnt find any specific trend.All i cud see that if all the rows have values then there is no problem. Best chance is to convert xlsx to xls.
Related
I'm trying to use my company's software, Visio Standard, to create an entity relationship database using Excel. Usually the team has been creating this manually due to not having access to the Professional versions. With a mulitude of entities, the process is extremely tedious doing this one by one. I am trying to import from Excel to Visio without that pro version.
Theoretically the excel template would have Entity Name, Entity Structure (P'ship, Corp, DRE, Individual, ect.) and whatever else information needed to automatically populate into excel.
I have a background in VBA so that could be utilized, I just keep running into roadblocks due to the lack of tabs that the standard version has, including the main Data tab for import.
Is there any way I can import my data from Excel into Visio then run a code to convert it into shapes? What about my own custom template?
We make entity relationship diagrams often so one template would not work. We have a standard shapes & stencils that is used across the board, but the ERD is never the same. I thought I needed a template but I realized that I can't convert a personal template to a wizard or import an excel to the template that the template becomes quite useless.
#Surrogate My idea is that I want to pull the data from a template in excel to automatically create the ERD (or close to it) to save a large sum of time creating those entities through the shapes one by one. I think the template in Excel being so basic, with header columns for the Name of the Entity, Shape to use, hierarchy ladder; VBA does come into play pretty easily, just unsure how to mess around with that since I can't import excel into Visio through the standard version
#y4cine I am stuck because I cannot import data from excel in the standard version.
#TimWilliams I'm not capable of poaching to paying for the pro version, so regardless of the "fun" I would like to see if I could work around the pro version to do what the ERD/wizard can do, even if it requires a large VBA macro.
because I cannot import data from excel in the standard version
This example uses early binding.
In VBA you need to set a reference to the Excel Library.
It sets prop values in already existing shapes. The link being the shape ID.
If you rather need to draw new shapes, I' recommend using a master.
something like:
dim oMaster as master
dim oStencil as document
set oStencil = Application.Documents("myStencil")
set oMaster = oStencil.Masters("myMaster")
then inside the loop:
define some coordinates for x and y
set shp = activepage.drop(oMaster,x,y)
The function:
Public Function excelImport(filename As String) As Boolean
Dim xlsWorkbook As Excel.Workbook
Dim xlsSheet As Excel.Worksheet
Dim shp As Visio.Shape
Dim num_rows As Integer
Dim row As Integer
Dim shpID As String
Set xlsWorkbook = Excel.Workbooks.Open(filename)
Set xlsSheet = xlsWorkbook.Worksheets(1)
num_rows = xlsSheet.Range("A65000").End(xlUp).row
For row = 2 To num_rows
shpID = xlsSheet.Range("P" & row).FormulaR1C1
If Not shpID = "" Then
Set shp = ActivePage.Shapes.ItemFromID(CLng(shpID))
shp.Cells("prop.SoAndSo").Formula = Chr(34) & xlsSheet.Range("A" & row).FormulaR1C1 & Chr(34)
End If
Next row
xlsSheet.Application.Quit
Set xlsSheet = Nothing
Set xlsWorkbook = Nothing
excelImport = True
End Function
I am currently working on a project that will import data from multiple different sources in a variety of formats and structures - e.g., CSV, fixed-length, other-delimited (tab, pipe, etc.) plain-text, and Excel worksheets/workbooks. For this, I'm attempting to build "generic" readers for these files which will throw the files' contents into a DataTable/DataSet I can use in other methods. The plain-text files are pretty simple as I've created a large SCHEMA.INI file which contains field definitions for each of the files the system will handle. That SCHEMA.INI resides in a "processing folder" where the files are temporarily stored until their data has been integrated with other systems. A defined text files' data can be easily extracted using this method:
Private Function TextFileToDataTable(ByVal TextFile As IO.FileInfo) As DataTable
Dim TextFileData As New DataTable("TextFileData")
Using TapeFileConnect As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OleDb.4.0;Data Source='" + TextFile.DirectoryName + "';Extended Properties='Text';")
Using TapeAdapter As New OleDb.OleDbDataAdapter(String.Format("SELECT * FROM {0};", TextFile.Name), TapeFileConnect)
Try
TapeAdapter.Fill(TextFileData)
Catch ex As Exception
TextFileData = Nothing
End Try
End Using
End Using
Return TextFileData
End Function
This works well because a plain-text file isn't terribly complex in its data structure. A single file generally (at least for my requirements) contains, at most, one single table's worth of data - unless, of course, it's some sort of complex XML or JSON structure file, which can/should be handled completely differently anyway - so there's no need to go iterating through different elements beyond this.
NOTE: The code above is dependent on the SCHEMA.INI file being present in the same directory as the plain-text file being read and there being a section within that SCHEMA.INI defined with the same name as that plain-text file.
EXAMPLE:
[EXAMPLE_TEXT_FILE.TXT]
CharacterSet=ANSI
Format=FixedLength
ColNameHeader=FALSE
DateTimeFormat="YYYYMMDD"
COL1=CUSTOMER_NUMBER TEXT WIDTH 20
COL2=CUSTOMER_FIRSTNAME TEXT WIDTH 30
COL3=CUSTOMER_LASTNAME TEXT WIDTH 40
COL4=CUSTOMER_ADDR1 TEXT WIDTH 40
COL5=CUSTOMER_ADDR2 TEXT WIDTH 40
COL6=CUSTOMER_ADDR3 TEXT WIDTH 40
...
Excel workbooks, however, can be a bit trickier. Several of the workbooks I have to process contain multiple worksheets worth of data that I want to consolidate into a single DataSet with a DataTable for each worksheet. The basic functionality is, again, fairly straightforward and I've come up with the following method to read any and all sheets into a DataSet:
Private Function ExcelFileToDataSet(ByVal ExcelFile As IO.FileInfo, ByVal HasHeaderRow As Boolean) As DataSet
Dim ExcelFileData As New DataSet("ExcelFileData")
Dim ExcelConnectionString As String = String.Empty
Dim UseHeaders As String = "NO"
Select Case ExcelFile.Extension.ToUpper.Trim
Case ".XLS"
ExcelConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties='Excel 8.0;HDR={1}'"
Case ".XLSX"
ExcelConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 8.0;HDR={1}'"
End Select
If HasHeaderRow Then
UseHeaders = "YES"
End If
ExcelConnectionString = String.Format(ExcelConnectionString, ExcelFile.FullName, UseHeaders)
Try
Using ExcelConnection As New OleDb.OleDbConnection(ExcelConnectionString)
Dim ExcelSchema As New DataTable
ExcelConnection.Open()
ExcelSchema = ExcelConnection.GetOleDbSchemaTable(OleDb.OleDbSchemaGuid.Tables, Nothing)
For Each ExcelSheet As DataRow In ExcelSchema.Rows
Dim SheetTable As New DataTable
Using ExcelAdapter As New OleDb.OleDbDataAdapter
Dim SheetName As String = ExcelSheet("TABLE_NAME").ToString
Dim ExcelCommand As New OleDb.OleDbCommand
SheetTable.TableName = SheetName.Substring(0, SheetName.Length - 1)
ExcelCommand.Connection = ExcelConnection
ExcelCommand.CommandText = String.Format("SELECT * FROM [{0}]", SheetName)
ExcelAdapter.SelectCommand = ExcelCommand
ExcelAdapter.Fill(SheetTable)
End Using
ExcelFileData.Tables.Add(SheetTable)
Next ExcelSheet
End Using
Catch ex As Exception
ExcelFileData = Nothing
End Try
Return ExcelFileData
End Function
The above code will work in a majority of the cases I deal with, but my "difficulty" is that there may be some worksheets that have header rows and some that don't within the same workbook. Also, for those worksheets that do not have a header row, I'd like to be able to define the field names and data types similar to how I can with the plain-text SCHEMA.INI. The only thing I have going for me in these cases is that the "client" provides me with a data map to help me identify what data elements are in each field.
What I'd like to know is if there is a way similar to the text file's SCHEMA.INI to define the structure of an Excel workbook and the worksheet(s) it contains - including column data types to avoid the OleDb driver from "misinterpreting" a column's data - ahead of time. I imagine this could be any sort of structured file such as INI, XML, or whatever, but it would need to be capable of identifying whether or not a particular sheet contains a header row or, in lieu of such a row, the (expected) column definitions. Does any such "standard definition" file exist for Excel workbooks?
One thing to note: As you may have noticed in the code for the ExcelFileToDataSet() method, I may be dealing with the older .XLS (97-03) format or the .XLSX (07+) format, so I can't necessarily rely on the workbook being Open XML compliant. I suppose I could try breaking the methods out to one for each extension, but I'd rather find something that I can use regardless of which file format the Excel file is using.
my question about import excel to datagridview but there is an extra case.
I have also a oledb database with store code and store names.
I want it to show only store codes from db that are in the database after imported.
my codes here;
Dim conn As OleDbConnection
Dim dtr As OleDbDataReader
Dim dta As OleDbDataAdapter
Dim cmd As OleDbCommand
Dim dts As DataSet
Dim excel As String
Dim OpenFileDialog As New OpenFileDialog
OpenFileDialog1.FileName = ""
OpenFileDialog1.InitialDirectory = My.Computer.FileSystem.SpecialDirectories.Desktop
OpenFileDialog1.Filter = "All Files (*.*)|*.*|Excel files (*.xlsx)|*.xlsx|CSV Files (*.csv)|*.csv|XLS Files (*.xls)|*xls"
If (OpenFileDialog1.ShowDialog(Me) = System.Windows.Forms.DialogResult.OK) Then
DataGridView1.Columns.Clear()
Dim fi As New FileInfo(OpenFileDialog1.FileName)
Dim FileName As String = OpenFileDialog1.FileName
excel = fi.FullName
conn = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + excel + ";Extended Properties=Excel 12.0;")
dta = New OleDbDataAdapter("Select * From [Sheet1$]", conn)
dts = New DataSet
dta.Fill(dts, "[Sheet1$]")
DataGridView1.DataSource = dts
DataGridView1.DataMember = "[Sheet1$]"
conn.Close()
End If
firstly sorry for my terrible english :)
images as follows;
Main Form
Store List Form
I want only the ones in the store list to be displayed in datagrid.. :\
It's not exactly clear what your current presentation/display looks like, what the problem is, and what your desired presentation/display should look like. But you have asked about selecting only one part of the data you are importing, which is presumably found in only one column of the imported Excel data.
When the datatable is created, it has the columns and rows from the Excel worksheet. The columns will be data from the first row, and the rows will be the records from the succeeding rows in the worksheet. You can access both the header data and the row data easily. The code below is VERY rough but for you to see how to gain access to the data in the datatable which you have already very successfully imported in the limited code shown above.
Dim columns = datatable.Columns
Dim rows = datatable.Rows
Dim columns1 = columns(0)
Dim rows1 = rows(0)
Dim element1 = rows1(0)
Columns will have all the headers, so you can locate the column with the store codes or store names. Then the rows will have the data for each store. So above, rows1 is the first row of data and element1 is the data in that row from columns1, and so on. The (0) is the index into the respective collections.
You will, of course, have to write code to extract the data you want and if necessary eliminate duplicates, but the data is all there already.
Hopefully getting the data into a list and then sorting, filtering and selecting the data should be relatively straightforward, but if not, add a comment. That's kind of a different problem. You asked about getting only the store codes.
Added: Based on your additional images and explanation, you are looking to perform an SQL INNER JOIN operation. From the w3schools.com page on SQL INNER JOIN, "The INNER JOIN keyword selects all rows from both tables as long as there is a match between the columns." This is something you will have to study and learn, but it should provide what you need in this case. You will need to define and construct both tables and then perform the JOIN.
And, by the way, you could also follow the link provided in the first comment by T.S., and if that solves your problem, it's a far simpler solution.
Is there any way to read all the data from excel and put it in the datatable or any other container so that i can filter the data based on the conditions required. As shown in attached image i want to get the CuValue of a Partnumber whose status is Success and i want the latest record based on the Calculation date(Latest calculation date). In the below example i want the CuValue 11292 as it is the latest record with status Success..lue.
Thanks in advance
Your question seems very broad, but you're right to ask because there are many different possibilities and pitfalls.
As you don't provide any sample code, i assume you are looking for a strategy, so here is it.
In short: create a database, a table and a stored procedure. Copy the
data you need in this table, and then query the table to get the
result.
You may use ADO for this task. If it is not available on your machine you can download and install the MDAC redistributable from the Microsoft web site.
The advantage vs. OLE Automation is that you doesn't need to install Excel on the target machine where the import shall be executed, so you can execute the import also server-side.
With ADO installed, you will need to create two Connection objects, a Recordset object to read the data from the Excel file and a Command object to execute a stored procedure which will do the INSERT or the UPDATE of the subset of the source fields in the destination table.
Following is a guideline which you should expand and adjust, if you find it useful for your task:
Option Explicit
Dim PartNo as String, CuValue as Long, Status as String, CalcDate as Date
' objects you need:
Dim srcConn As New ADODB.Connection
Dim cmd As New ADODB.Command
Dim rs As New ADODB.Recordset
Dim dstConn As New ADODB.Connection
' Example connection with your destination database
dstConn.Open *your connection string*
'Example connection with Excel - HDR is discussed below
srcConn.Open "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:\Scripts\Test.xls;" & _
"Extended Properties=""Excel 8.0; HDR=NO;"";"
rs.Open "SELECT * FROM [Sheet1$]", _
srcConn, adOpenForwardOnly, adLockReadOnly, adCmdText
' Import
Do Until rs.EOF
PartNo = rs.Fields.Item(0);
CuValue = rs.Fields.Item(1);
CalcDate = rs.Fields.Item(6);
Status = rs.Fields.Item(7);
If Status = "Success" Then
'NumSuccess = NumSuccess + 1
' copy data to your database
' using a stored procedure
cmd.CommandText = "InsertWithDateCheck"
cmd.CommandType = adCmdStoredProc
cmd(1) = PartNo
cmd(2) = CuValue
cmd(3) = CalcDate
cmd.ActiveConnection = dstConn
cmd.Execute
Else
'NumFail = NumFail + 1
End If
rs.MoveNext
Loop
rs.Close
Set rs = Nothing
srcConn.Close
Set srcConn = Nothing
dstConn.Close
Set dstConn = Nothing
'
By using a stored procedure to check the data and execute the insert or update in your new table, you will be able to read from Excel in fast forward-only mode and write a copy of the data with the minimum of time loss, delegating to the database engine half the work.
You see, the stored procedure will receive three values. Inside the stored procedure you should insert or update this values. Primary key of the table shall be PartNo. Check the Calculation Date and, if more recent, update CuValue.
By googling on the net you will find enough samples to write such a stored procedure.
After your table is populated, just use another recordset to get the data and whatever tool you need to display the values.
Pitfalls reading from Excel:
The provider of your Excel file shall agree to remove the first two or three rows, otherwise you will have some more work for the creation of a fictitious recordset, because the intelligent datatype recognition of Excel may fail.
As you know, Excel cells are not constrained to the same data type per-column as in almost all databases.
If you maintain the field names, use HDR=YES, without all the first three rows, use HDR=NO.
Always keep a log of the "Success" and "Fail" number of records read
in your program, then compare these values with the original overall
number of rows in Excel.
Feel free to ask for more details, anyway i think this should be enough for you to start.
There are lots ways you can do this.
1. You can create an access DB table and import by saving your sheet as can file first, into the access table. Then you can write queries.
2. You can create a sql DB and a table, write some code to import the sheet into that table.
3. You can Write some code in VBA and accomplish that task if your data is not very big.
4. You can write c# code to access the sheet using excel.application and office objects, create a data table and query that data table
Depends on what skills you want to employ to accomplish your task.
Currently I have an application that takes information from a SQLite database and puts it to Excel. However, I'm having to take each DataRow, iterate through each item, and put each value into it's own cell and determine highlighting. What this is causing is 20 minutes to export a 9000 record file into Excel. I'm sure it can be done quicker than that. My thoughts are that I could use a data source to fill the Excel Range and then use the column headers and row numbers to format only those rows that need to be formatted. However, when I look online, no matter what I seem to type, it always shows examples of using Excel as a database, nothing about importing into excel. Unless I'm forgetting a key word or to. Now, this function has to be done in code as it's part of a bigger application. Otherwise I would just have Excel connect to the DB and pull the information itself. Unfortunately that's not the case. Any information that could assist me in quick loading an excel sheet would be appreciated. Thanks.Additional Information:Another reason why the pulling of the information from the DB has to be done in code is that not every computer this is loaded on will have Excel on it. The person using the application may simply be told to export the data and email it to their supervisor. The setup app includes the needed dlls for the application to make the proper format.Example Code (Current):
For Each strTemp In strColumns
excelRange = worksheet.Cells(1, nCounter)
excelRange.Select()
excelRange.Value2 = strTemp
excelRange.Interior.Color = System.Drawing.Color.Gray.ToArgb()
excelRange.BorderAround(Excel.XlLineStyle.xlContinuous, Excel.XlBorderWeight.xlThin, Excel.XlColorIndex.xlColorIndexAutomatic, Type.Missing)
nCounter += 1
Next
Now, this is only example code in terms of the iteration I'm doing. Where I'm really processing the information from the database I'm iterating through a dataTable's Rows, then iterating through the items in the dataRow and doing essentially the same as above; value by value, selecting the range and putting the value in the cell, formatting the cell if it's part of a report (not always gray), and moving onto the next set of data. What I'd like to do is put all of the data in the excel sheet (A2:??, not a row, but multiple rows) then iterate through the reports and format each row then. That way, the only time I iterate through all of the records is when every record is part of a report.
Ideal Code
excelRange = worksheet.Cells("A2", "P9000")
excelRange.DataSource = ds 'ds would be a queried dataSet, and I know there is no excelRange.DataSource.
'Iteration code to format cells
Update:
I know my examples were in VB, but it's because I was also trying to write a VB version of the application since my boss prefers VB. However, here's my final code using a Recordset. The ConvertToRecordset function was obtained from here.
private void CreatePartSheet(Excel.Worksheet excelWorksheet)
{
_dataFactory.RevertDatabase();
excelWorksheet.Name = "Part Sheet";
string[] strColumns = Constants.strExcelPartHeaders;
CreateSheetHeader(excelWorksheet, strColumns);
System.Drawing.Color clrPink = System.Drawing.Color.FromArgb(203, 192, 255);
System.Drawing.Color clrGreen = System.Drawing.Color.FromArgb(100, 225, 137);
string[] strValuesAndTitles = {/*...Column Names...*/};
List<string> lstColumns = strValuesAndTitles.ToList<string>();
System.Data.DataSet ds = _dataFactory.GetDataSet(Queries.strExport);
ADODB.Recordset rs = ConvertToRecordset(ds.Tables[0]);
excelRange = excelWorksheet.get_Range("A2", "ZZ" + rs.RecordCount.ToString());
excelRange.Cells.CopyFromRecordset(rs, rs.RecordCount, rs.Fields.Count);
int nFieldCount = rs.Fields.Count;
for (int nCounter = 0; nCounter < rs.RecordCount; nCounter++)
{
int nRowCounter = nCounter + 2;
List<ReportRecord> rrPartReports = _lstReports.FindAll(rr => rr.PartID == nCounter).ToList<ReportRecord>();
excelRange = (Excel.Range)excelWorksheet.get_Range("A" + nRowCounter.ToString(), "K" + nRowCounter.ToString());
excelRange.Select();
excelRange.NumberFormat = "#";
if (rrPartReports.Count > 0)
{
excelRange.Interior.Color = System.Drawing.Color.FromArgb(230, 216, 173).ToArgb(); //Light Blue
foreach (ReportRecord rr in rrPartReports)
{
if (lstColumns.Contains(rr.Title))
{
excelRange = (Excel.Range)excelWorksheet.Cells[nRowCounter, lstColumns.IndexOf(rr.Title) + 1];
excelRange.Interior.Color = rr.Description.ToUpper().Contains("TAG") ? clrGreen.ToArgb() : clrPink.ToArgb();
if (rr.Description.ToUpper().Contains("TAG"))
{
rs.Find("PART_ID=" + (nCounter + 1).ToString(), 0, ADODB.SearchDirectionEnum.adSearchForward, "");
excelRange.AddComment(Environment.UserName + ": " + _dataFactory.GetTaggedPartPrevValue(rs.Fields["POSITION"].Value.ToString(), rr.Title));
}
}
}
}
if (nRowCounter++ % 500 == 0)
{
progress.ProgressComplete = ((double)nRowCounter / (double)rs.RecordCount) * (double)100;
Notify();
}
}
rs.Close();
excelWorksheet.Columns.AutoFit();
progress.Message = "Done Exporting to Excel";
Notify();
_dataFactory.RestoreDatabase();
}
Can you use ODBC?
''http://www.ch-werner.de/sqliteodbc/
dbName = "c:\docs\test"
scn = "DRIVER=SQLite3 ODBC Driver;Database=" & dbName _
& ";LongNames=0;Timeout=1000;NoTXN=0;SyncPragma=NORMAL;StepAPI=0;"
Set cn = CreateObject("ADODB.Connection")
cn.Open scn
Set rs = CreateObject("ADODB.Recordset")
rs.Open "select * from test", cn
Worksheets("Sheet3").Cells(2, 1).CopyFromRecordset rs
BTW, Excel is quite happy with HTML and internal style sheets.
I have used the Excel XML file format in the past to write directly to an output file or stream. It may not be appropriate for your application, but writing XML is much faster and bypasses the overhead of interacting with the Excel Application. Check out this Introduction to Excel XML post.
Update:
There are also a number of libraries (free and commercial) which can make creating excel document easier for example excellibrary which doesn't support the new format yet. There are others mentioned in the answers to Create Excel (.XLS and .XLSX) file from C#
Excel has the facility to write all the data from a ADO or DAO recordset in a single operation using the CopyFromRecordset method.
Code snippet:
Sheets("Sheet1").Range("A1").CopyFromRecordset rst
I'd normally recommend using Excel to pull in the data from SQLite. Use Excel's "Other Data Sources". You could then choose your OLE DB provider, use a connection string, what-have-you.
It sounds, however, that the real value of your code is the formatting of the cells, rather than the transfer of data.
Perhaps refactor the process to:
have Excel import the data
use your code to open the Excel spreadsheet, and apply formatting
I'm not sure if that is an appropriate set of processes for you, but perhaps something to consider?
Try this out:
http://office.microsoft.com/en-au/excel-help/use-microsoft-query-to-retrieve-external-data-HA010099664.aspx
Perhaps post some code, and we might be able to track down any issues.
I'd consider this chain of events:
query the SQLite database for your dataset.
move the data out of ADO.NET objects, and into POCO objects. Stop using DataTables/Rows.
use For Each to insert into Excel.