This article describes the way to read or write into the excel workbook(or a file, used interchangeably) pro-grammatically using C#.NET language and ACE Oledb data providers by Microsoft. This covers the following topics:.
Excel 2010 crashes when attempting to open ADODB.Connection. Hi All, I hope everyone is well and hope someone might be able to suggest how to resolve the below issue. My Excel 2010 crashes when attempting to open ADODB.Connection (establishing connection to later use recordset to read contents of another sheet within the same Excel file). I installed Access Databaes 2010 64-bit as I have 64-bit version of Office 2010 installed. I changed the target platform of the project to Any CPU. I also realized that I did some mistake in connection string.
System Requirements. Development Environment. Versions of Excel files which can be read or written. How to build a connection string?. How to build a command string?. Possible errors and exceptions System Requirements To read/write the excel worksheet using ACE oledb providers, MS office need not to be installed on a machine.
An installable package containing ACE oledb providers can be installed from Go to this link to install the required version and also check the system requirements. Note: You can install either 32 bits version or 64 bits version but not both. Also, if you have 64 bits office installed then you can’t install 32 bits ACE oledb and vice versa. Check the requirements carefully on the page. Development Environment. ACE 12.0 oledb Data Providers dlls. Development IDE – Visual Studio or simple Notepad Versions of Excel files which can be read or written This ACE 12.0 oledb data provider can carry out operations on all excel files till version 2010.
How to build a Connection String? A typical example of connection string: Provider=Microsoft.ACE.OLEDB.8.0;Data Source=;Extended Properties='Excel 8.0;' Below is the description for each part:.
Provider: It is the main oledb provider that is used to open the excel sheet. This can be Microsoft.Jet.OLEDB.4.0 for Excel 97 onwards Excel file format or Microsoft.ACE.OLEDB.12.0. So far it is tested with upto Excel 2010 version.
Data Source: It is the full path of the excel workbook. Replace with the full path of your existing excel workbook/ file. Extended Properties (Optional): Extended properties can be applied to Excel workbooks which may change the overall activity of the excel workbook from your program.
The most common ones are the following:. HDR: It represents Header of the fields in the excel table. Default is YES.
If you dont have fieldnames in the header of your worksheet, you can specify HDR=NO which will take the columns of the tables that it finds as f1,f2 etc. ReadOnly: You can also open excel workbook in readonly mode by specifying ReadOnly=true; By Default Readonly attribute is false, so you can modify data within your workbook.
FirstRowHasNames: It is the same as HDR, it is always set to 1 ( which means true) you can specify it as false if you dont have your header row. If HDR is YES provider disregards this property.
You can change the default behaviour of your environment by changing the Registry Value- HKLM Software Microsoft Jet 4.0 Engines Excel FirstRowHasNames to 00 (which is false). MaxScanRows: Excel does not provide the detailed schema defination of the tables it finds. It need to scan the rows before deciding the data types of the fields.
MaxScanRows specifies the number of cells to be scanned before deciding the data type of the column. By default the value of this is 8. You can specify any value from 1 – 16 for 1 to 16 rows. You can also make the value to 0 so that it searches all existing rows before deciding the data type. You can change the default behaviour of this property by changing the value of HKLM Software Microsoft Jet 4.0 Engines Excel TypeGuessRows which is 8 by default. Currently MaxScanRows is ignored, so you need only to depend on TypeGuessRows Registry value. Hope Microsoft fixes this issue to its later versions.
IMEX: (A Caution) As mentioned above excel have to guess a number or rows to select the most appropriate data type of the column, a serious problem may occur of you have mixed data in one column. Say you have data of both integer and text on a single column, in that case excel will choose its data type based on majority of the data. Thus it selects the data for the majority data type that is selected, and returns NULL for the minority data type. If the two types are equally mixed in the column, the provider chooses numeric over text. For e.g., In your eight (8) scanned rows, if the column contains five (5) numeric values and three (3) text values, the provider returns five (5) numbers and three (3) null values. To work around this problem for data, set “IMEX=1” in the Extended Properties section of the connection string.
This enforces the ImportMixedTypes=Text registry setting. You can change the enforcement of type by changing HKLM Software Microsoft Jet 4.0 Engines Excel ImportMixedTypes to numeric as well Thus if you look into the simple connectionstring with all of them, it will look like: Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E: testexcel.xls;Extended Properties= 'Excel 8.0;HDR=YES;IMEX=1;MAXSCANROWS=15;READONLY=FALSE ' or Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E: testexcel.xlsx;Extended Properties= 'Excel 12.0;HDR=YES;IMEX=1;MAXSCANROWS=15;READONLY=FALSE ' How to build a command string? If you have ever written a MS SQL query then you will not have difficulty in writing a command string. Here, command strings are written or defined in the same fashion as in MS SQL. Think of each excel sheet as a MS SQL table from which data is to be fetched. Thus, complete excel file as a database. Below image is the snapshot of a sample excel sheet which we will try to read or write into.
![Find Find](http://3.bp.blogspot.com/-sIsd8fyydic/UqI5tWoO5vI/AAAAAAAADpM/iwkA2a-Vmgc/s1600/Untitled.png)
Read Command String In order to read the excel sheet, “SELECT” command is used. Either you may want to read the complete excel sheet or you may be interested in reading just a block of data. Both scenarios are supported and this is what us different from defining the MS SQL “Select” query. Range (block of data) is defined using A2:R5 format.
Don’t worry about ranges. I have described it in the below section. How to read complete excel sheet? Below is the sample command string to read the complete data in an excel sheet: Select. from NameOfExcelSheet$ Here, NameOfExcelSheet is the name of an excel sheet. Excel file can have multiple sheets.
So, one has to specify the name of the sheet in order to fetch the data. This command string reads the complete excel sheet. Note: This may read empty rows, columns as well if there is any hidden data or there are empty rows in b/w the filled data. How to specify range to read a block of data from excel sheet? Below is the sample command string to read the complete data in an excel sheet: Select. from NameOfExcelSheet$ A1:E5 Here, NameOfExcelSheet is the name of the excel sheet.
Excel file/workbook can have multiple sheets. So, one has to specify the name of the sheet in order to fetch the data.
This command string reads the complete excel sheet. And, text after ‘$’ sin specifies the range of data to be read.
Thus, as per the above command string, it will read the data from the excel cell A1 till E5. In other words, it will read 5 rows from row# ‘1’ to ‘5’ and 5 columns from column# ‘A’ to ‘E’. This can be beneficial in reading the data in chunks which can be easily achieved by dynamically specifying the range in the above format.
Another way to specify range is: Select. from NameOfExcelSheet$ A1:E Here, as per the above command string, it will read all rows starting from row# ‘1’ and 5 columns from column# ‘A’ to ‘E’ Write Command String This also corresponds to DML queries (INSERT,UPDATE and DELETE) in MS SQL. You can write: INSERT INTO NameOfExcelSheet VALUES('firsttextcol', 2, '4/11/2009'); I assume First Column is char field, 2nd col is integer, 3rd is Date DELETE FROM NameOfExcelSheet Where secondintcol=2; UPDATE NameOfExcelSheet SET secondintcol = 3 where firsttextcol = ‘firsttextcol’; As in MS SQL, you can use (Square brackets) to allow spaces within column names and table names. How to create an excel worksheet? Use Create table NameOfExcelSheet For e.g.
Create table myTableName (col1 int, col2 char(20)) How to Drop an excel workSheet? To drop an excel worksheet, just use Drop table NameOfExcelSheet This will drop the worksheet. Note:. About Deleting Worksheet: If this is the last worksheet, it will not delete the workbook file. You need to do it yourself. About specifying ranges: When you specify a worksheet as your source, the provider adds new records below existing records in the worksheet as space allows.
When you specify a range (named or unnamed), Jet also adds new records below the existing records in the range as space allows. However, if you requery on the original range, the resulting recordset does not include the newly added records outside the range. Using MDAC you cannot add new rows beyond the defined limits of the range, otherwise you will receive Exception: “Cannot expand named range” Possible errors and exceptions.
1)”Microsoft.ACE.OLEDB.12.0-provider” is not registered Reason:This is because of mismatch b/w compilation configuration in Visual Studio and the ACE version installed on the system. Resolution:Make sure that both are same. Compile your app using the 64x bits if 64 bits ACE is installed or use 32 bits ACE. After all the issues like ACE.OLEDB.12.0 is not installed in your machine and could not find installable isam, i am getting another error “Cannot modify the design of table ‘Persons’. It is in a read-only database.”. I am tring to create table in Excel sheet here is the code m using string con2 = “Provider=Microsoft.ACE.OLEDB.12.0;Data Source= ” + flpath + “;Extended Properties= ”Excel 12.0;HDR=YES;IMEX=1;READONLY=FALSE ””; OleDbConnection mycon1 = new OleDbConnection(con2); mycon1.Open; OleDbCommand cmd2 = new OleDbCommand(“CREATE TABLE Persons( PId int, LastName varchar(255), FirstName varchar(255), Address varchar(255), City varchar(255) )”,mycon1); cmd2.ExecuteNonQuery; Like.
I'm in Windows 7 running Office 2010. I have an Excel 2010 file that queries an Access 2010 database. When I open the Excel file, I get the 'Could Not Find Installable ISAM' error.
If I click 'OK' and then answer 'yes' to the next message box (Do you still want to connect to.accdb?), it seems to return the correct information. However, this is annoying and - more importantly - it confuses my users.
I do not get this message when I run the query from within Access. It is only when I run from Excel. I looked at some of the other posts relative to this error, but I was concerned about the solutions because they were generally speaking in terms of Office 2003 and I know there are alot of changes since 2007, particularly with Access and Excel.
This morning's events: 1) I got the same error; 2) I went to the Connection Properties in Excel and added the recommended syntax; 3) When I clicked 'OK', the dialog closed, and I got the 'Cannot Find Installable ISAM' error. This is new because the only other times I've seen this error is upon opening the workbook. 4) I looked back in the definition, and the added syntax is gone.
5) I closed the workbook without saving and reopened. I did not get the ISAM error, but now it asks me four times if I want to connect to the accdb file (one for each connection). It is the same dialog box I received AFTER the ISAM error, but now I get just this dialog box without the ISAM error first. To clarify, yesterday when the problem went away, I received neither. So this is still different. 6) I still don't see the added syntax in the Connection String in the Definition tab of the Connection Properties dialog.
7) Looks like I picked the wrong week to stop smoking crack (just kidding) Ideas? Did you find a solution to your problem? I have the same problem happen in this type of scenario. My laptop has access 2k3 and 2k10 installed and office 2k10. If I create a workbook and bring in data from an Access database in(in 2003 format) my excel inserts that bypass user string.
However If I go on a desktop that has office 2k3 and office 2k10 installed and create the workbook the user bypass doesn't not get added. Furthur more I can remove the string on the desktop, save and reopen and the ISAM error does not appear. But as soon as I reopen, refresh the connections on my laptop and save the file the connections go back. Its really irritating and I don't understand what M$ install is causing it. Without reformatting my laptop I am foreced to create and update everything on the desktop. Both are work PCs too which make it hard to reformat. I have been trying anything I can to discover the cause.
Infact I can even get the userby pass to happen if I open the workbooks in excel 2k3(which i've since removed) and save and close. I have a feeling I need to rip out both versions of access and reinstall.
I believe thats where the issue comes from. Hope my situation helps shed some light on a fix for BBNB. Sorry I didn't mean to be confusing.
I was trying to state that I have a laptop that I is causing the problem. If I open up any excel reports that i've created on other PCs the error occurs. If I remove the Jet OLEDB:Bypass UserInfo Validation=False string in the report on any other PC, save and close, none gets the error. Its only when I use my laptop to open the report and let the data refresh. Its at that moment that the Jet OLEDB:Bypass UserInfo Validation=False string gets inserted back into the connection. Since my last post I removed all versions of excel except 2010 and removed all versions Access and reinstalled 2010.
So now my laptop only has 2010. The problem still remains if I open a report and refresh data.
The string goes back in. I have given up on trying to fix the problem as I believe its another install on my PC that introduced the connectioin type.
Since its a work PC and I can not readily reformat it or replace it I will wait till my hardware refresh date and hopefully it will not comeback with a new pc. My work around: Don't save any excel file on my laptop that other people need to use. Hi, Any more news on this? I'm having exactly the same trouble, but can add a bit more behavioural detail to this.
Not only does the ISAM error appear, but when you click the 'Yes' on the 2nd option, the database then enters a locked state, preventing other users from updating data in the tables.