I need to fetch all databases of Microsoft Access in localhost.
On clicking the database name I have to list the tables
I can able to fetch the tables for a particular database.
My problem is I cant able to list out the MS Access databases available in localhost
please suggest me the ideas to start coding
I tried
OleDbConnection con; // create connection
OleDbCommand com; // create command
OleDbDataReader dr; //Data read for read data from database
con = new OleDbConnection("Provider = Microsoft.Jet.OLEDB.4.0; Data Source =D:\mydb.mdb");
com = new OleDbCommand("Select * from Table1",con);
con.Open(); // open the connection dr = com.ExecuteReader();
expected result:
with out mentioning Data Source =D:\mydb.mdb" i have to list all ms access databases of
localhost
All available databases like
database1.accdb
database2.accdb
Access (or Jet, to use the name of the database engine) doesn't run a server, in the way that Sql Server or MySql do. An Access database is simply a file of particular format that is loaded on request, but the Jet engine libraries.
For this reason, there's no simple way to find all databases on a local machine: you would need to scan all files on the machine for .accdb or .mdb extensions. More likely, you should ask the user to select a specific file or scan a specified subfolder, since searching the whole machine will likely take a prohibitively long time.
Related
The following script works within a SQL Server 2014 Management Studio in a Stored Procedure but not when I call the stored proc via a C# app .NET Framework 4.8.
SQL Code:
create proc getData
as
Insert INTO tmpLeaveImport ([CarName], Year, Make , Model)
SELECT * FROM OPENROWSET('Microsoft.ACE.OLEDB.15.0',
'Excel 12.0;Database=E:\Cars\Cars.xlsx',
'SELECT * FROM [Car Report$]')
From C# I get the following error:
System.Data.SqlClient.SqlException: 'Cannot initialize the data source
object of OLE DB provider "Microsoft.ACE.OLEDB.15.0" for linked server
"(null)". OLE DB provider "Microsoft.ACE.OLEDB.15.0" for linked server
"(null)" returned message "Unspecified error".'
When this code is executed in C#:
//Tried the conn strign with Integrated Security=yes and SSPI
string ConnString = #"Data Sournce=MySQLServerDB;Initial Catalog=DBName;Integrated Security=true;";
using (SqlConnection conn = new SqlConnection(ConnString))
{
using (SqlCommand cmd = conn.CreateCommand())
{
conn.Open();
cmd.CommandText = "getData";
cmd.CommandType = CommandType.StoredProcedure;
cmd.ExecuteNonQuery();
}
conn.Open();
}
Short Version
According to this possibly duplicate question the Excel file may be open. Or this could be a more serious error.
Don't use OPENROWSET to import Excel data into SQL Server. Use a library like ExcelDataReader to read it without using the Access Engine and insert it to the target table with SqlBulkCopy. You'll avoid a lot of pain.
using (var stream = File.Open(filePath, FileMode.Open, FileAccess.Read))
{
using (var reader = ExcelReaderFactory.CreateReader(stream))
{
using (var bcp = new SqlBulkCopy(connString))
{
bcp.DestinationTableName ="SomeTable";
bcp.WriteToServer(reader);
}
}
}
Long Version
In both cases, the stored procedure runs on SQL Server, not on the client. SSMS is just another client as far as SQL Server is concerned. Assuming the same server is used in both cases, what's different is that the account that executes the stored procedure is different in each case.
With SSMS, it's the developer's account which quite often has sysadmin privileges on the server. With C#, the account may be the end user's, or the application pool account that runs a web site, which has very restricted privileges. SQL Server's default service account is a restricted account too.
This matters because the Access Engine is a COM component. To use it, applications need to look it up in the registry, which requires its own permissions. If you search SO for the error you got you'll see questions where the choice of service account affected whether Access Engine can be used or not. In other cases, the file was open.
Another potential problem is that ACE must target the same architecture as any previous Office components installed on a machine. If you have a x86 Office application, you can only install the x86 version of ACE. That's because you can't use COM component created for one architecture from a process that targets another one.
This also means you can't use an x86 ACE in a x64 installation of SQL Server, which is the most common installation option in the last 10+ years.
I am writing code for a small company that is all about purchase and sell. I wrote C# code with using external database (SQL Server 2014), now it's time to make the exe file of that code.
I tried my best but it doesn't work.
How can I connect SQL Server 2014 database files with my application so that when someone installs it on his computer he also got SQL Server connected with that application?
Hi actually we deploy code as setup file (.msi), you can create setup project using Wix or install-shield ( maybe other too,but these two are most popular and widely used)
You can do database deployment in two ways
1.) you can provide SQL script for generating SQL server and give instruction for generating Database from Script. It is simple and easy to do.
2.) Other way is provide option to create database from setup. It need some work, but it is more good way.
Now come to your question, you can provide some UI in setup that take input from user and connect to appropriate DB. Or create a UI for Updating configurations, and save configuration (connection string ) in some file ( ex: .ini or .config file).
Below are the some URL for creating Setup and connecting to Db using Wix:
WIXDataBase
installing-databases-using-wix
Creating-an-installer-using-Wix
using-wix-to-install-sql-databases-and-execute-sql-scripts
WiX Samples
Ideally you'd have a SQL server set up somewhere. If not you'll have to install sql server. In your app it's just a matter of setting up the connection string and running sql commands against it.
string connectionString = "Data Source=server //rest of connection string"
Then in c# you can do
using (SqlConnection con = new SqlConnection(connectionString))
{
using (SqlCommand command = new SqlCommand("SELECT TOP 100 * FROM SomeTable", con))
using (SqlDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine("{0} {1} {2}",
reader.GetString(0), reader.GetString(1), reader.GetString(2));
}
}
}
GetString can be changed to GetInt or whatever the datatable will be. This should be enough information to get you started. If you know the structure of the database its simple to put the results into your classes for the application.
Context
My appliction uses an SQL database from which it reads my datatables at start of my application. If the application would fail to connect to the SQL DB, I have a local Ms Access .MDB file. I have a separate thread that checks if the local database is outdated.
I have a DataTable which I obtain from my SQL connection --> Verified and working
I can connect to my Access database locally and read from it --> Verified and working
Issue/Question
I'm trying to update my local database by updating it with the DataTable I obtained from my SQL Connection.
public static void UpdateLocalDatabase(string strTableName, OleDbConnection MyConnection, DataTable MyTable)
{
try
{
if (CreateDatabaseConnection() != null)
{
string strQuery = "SELECT * FROM " + strTableName;
OleDbDataAdapter MyAdapter = new OleDbDataAdapter();
OleDbCommandBuilder MyCommandBuilder = new OleDbCommandBuilder(MyAdapter);
MyAdapter.SelectCommand = new OleDbCommand(strQuery, odcConnection);
MyAdapter.UpdateCommand = MyCommandBuilder.GetUpdateCommand();
MyConn.Open();
MyAdapter.Update(MyTable);
MyConn.Close();
}
}
catch { }
}
If I debug this snippet, all variables are what they should be:
strTableName = the correct name for my table
MyConn = #"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=MyLocation;Persist Security Info=True;JET OLEDB:Database Password=MyPassword;"
MyTable = is the correct table that is also used further on by my application
This process runs through without an error and without using the catch but it does not touch my database, it just doesn't do a thing.
Am I dropping the ball here or just missing the obvious, I have no idea but I browsed many articles and apart for showing the MyAdapter.Update(), there doesn't seem to be much more to it.
Any help is welcome.
Thanks,
Kevin
Does your backup database have to be in access? because if you used SQL Compact Edition it'd be much easier to copy between the two?
Yes, it would either mean attaching it with your installer or just ensuring that all client machines have it pre-installed, it is free however.
if this is an issue then all you need to do (I think, not done it myself)
would be to go to your installer projects properties, click prerequisites and then tick SQL compact so that it will be installed before your application can be used, iv done this before with other frameworks and it just pops up a box with the install shield asking whether they want to download the necessary software and its just one click then it should be done for them.
Do you need a hand on using the compact database also?
One negative by the way is it does lack some higher end features but shouldn't affect average database work
EDIT
if you will be using sql CE you can easily make the databse in VS by clicking data and new data source then following the steps making sure to put sql CE when asked
if it works, you'll end up with an .sdf database
I provided a code snippet that fixed the issue on my related question here: Export SQL DataBase to WinForm DataSet and then to MDB Database using DataSet
I'm trying to search the Indexing Service of a remote Windows 2003 server from ASP.NET. There's sample code for this on the MS site, but only for local searches. Here's what I've got so far; the remote server in this example is called "indexserver", isn't on a domain, and has a index called "system":
OleDbConnection conn = new OleDbConnection();
conn.ConnectionString = "Provider=MSIDXS;User ID=administrator;Password=Password";
OleDbCommand cmd = conn.CreateCommand();
cmd.CommandText= "SELECT * FROM indexserver.system..FILEINFO";
conn.Open();
cmd.ExecuteReader();
Running this gives me the error "Multiple-step OLE DB operation generated errors. Check the OLE DB status if available. No work was done".
Does anyone know how to get this working? All I need to do is query the Index for a filename and get the path of that file back.
Never mind, I discovered that Windows Indexing Service is somewhat depreciated,and Windows Search seems to be the way to go...
We are trying to build a Help Desk ticketing system just for intranet. Deciding upon the ASP .NET (C#) with Visual Studio 2008 Express (think we have a full version floating around if we need it). Nothing fancy, couple of pages grabbing NTLM information, system information and storing it along with their problem in a database. Goal is to make it simple, but instead of using our SQL Server 2000 back end, the admin wants me to use MS Access. I have the GridView and connections running smooth. Can pull select queries until my heart is content. However, tying in a couple variables with a text box on a submit button into say an INSERT statement.. well I don't even know where to begin with MS Access. Every internet example is in VB .NET plus seems to be hand coding what Visual Studio has already done for me in a few clicks.
Is MS Access going to be too hard for all we want to do? If not, where do we begin to simply submit this data into the tables?
Edit: After a bunch of playing around we have the OleDB working. It's not pretty, yes SQL Server would be awesome but, sometimes you just have to play ball.
Edit: Anyone looking for an actual coded answer, here you are. There has got to be others out there in the same boat.
string userIP = Request.UserHostAddress.ToString();
string userDNS = Request.UserHostName.ToString();
string duser = Request.ServerVariables["LOGON_USER"]; //NTLM Domain\Username
string computer = System.Environment.MachineName.ToString(); //Computer Name
string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\helpdesk.MDB;";
OleDbConnection conn = new OleDbConnection(connectionString);
conn.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = conn;
cmd.CommandText = "INSERT INTO ticketing ([user], [comp], [issue]) VALUES (#duser, #computer, #col3)";
cmd.Parameters.Add("#duser", OleDbType.VarChar).Value = duser;
cmd.Parameters.Add("#computer", OleDbType.VarChar).Value = computer;
cmd.Parameters.Add("#col3", OleDbType.LongVarChar).Value = TextBox1.Text;
cmd.ExecuteNonQuery();
conn.Close();
The admin is nuts. Access is an in-process database, and as such is not well suited for web sites where users will be creating or updating records.
But as far as creating INSERT queries go, Access is no harder than anything else. If you can't create INSERT queries for Access you'll probably have trouble with SQL Server as well.
I also suggest using SQL Server, but considering your problem:
What is your problem writing an INSERT query for Access ?
You should make use of the classes that you'll find in the System.Data.OleDb namespace:
OleDbConnection
OleDbCommand
Quick'n dirty code (not compiled whatsoever):
OleDbConnection conn = new OleDbConnection (connectionString);
OleDbCommand command = new OleDbCommand();
command.Connection = conn;
command.CommandText= "INSERT INTO myTable (col1, col2) VALUES (#p_col1, #p_col2)";
command.Parameters.Add ("#p_col1", OleDbType.String).Value = textBox1.Text;
...
command.ExecuteNonQUery();
There are some caveats with the OleDb classes however (like adding the Parameters to the collection in the order that they occur in your SQL statement, for instance).
Don't bother with Access. Use SQL Server Express. There's also an admin tool for it that looks like the full blown SQL Server management tool.
Access has its place, and can usually do more than what most people give it credit for, but yes you want to use SQL Server in ones of its many forms (eg. SQL Server Express) or another proper "server" database for a web app like this.