I am working on an ASP.NET project, which uses C# for code-behind. It attempts to connect to an Oracle database using the following code, which already existed in the project when I began working on it:
OracleConnection myConnection = new OracleConnection();
myConnection.ConnectionString = ConfigurationManager.ConnectionStrings["OraFinCnString"].ConnectionString;
myConnection.Open();
The application runs locally (opens up in a browser on localhost), and attempts to connect to a remote Oracle Database. When I run it, the The last line above gives the following error:
"InvalidOperationException was unhandled by user code. Attempt to load Oracle client libraries threw BadImageFormatException. This problem will occur when running in 64 bit mode with the 32 bit Oracle client components installed."
The connection string was provided by my client, so I presume it is correct, and this doesn't seem like the sort of error that would be caused by incorrect connection information. But I'm pretty well stumped as to exactly what the problem is, and would appreciate any insight.
Please take a look at the following link. You will need to Install Oracle 11g Oracle Data Access Components
Oracle Provider
Related
I am attempting to connect to an IBM DB2 database from a .NET 5 console application. This works fine against DB2 LUW in a local Docker instance, but fails when connecting to a z/OS mainframe instance.
Server:
IBM DB2 v11.5
z/OS
Client:
.NET 5 console application
IBM.Data.DB2.Core (v3.1.0.400)
IBM Data Server Driver (v11.5)
Error:
IBM.Data.DB2.Core.DB2Exception (0x80004005): ERROR [57017] [IBM] SQL0332N Character conversion from the source code page "" to the target code page "" is not supported. SQLSTATE=57017
at IBM.Data.DB2.Core.DB2ConnPool.Open(DB2Connection connection, String& szConnectionString, DB2ConnSettings& ppSettings, Object& ppConn)
at IBM.Data.DB2.Core.DB2Connection.Open()
at <my code>
Connection string:
Database=<redacted>;User ID=<redacted>;Password=<redacted>;Server=<redacted>:448;Persist Security Info=True;CurrentSchema=<redacted>;Connect Timeout=30
Opening connection:
var connection = new DB2Connection(connectionString);
try
{
connection.Open();
}
catch (DB2Exception e)
{
logger.LogError("Unable to access DB2 instance");
logger.LogError(e.ToString());
throw new DbAccessAcception(e);
}
The DB user I am testing with is already in use by another .NET program to connect to this database, though that app is older (.NET Framework 3.5).
What I've tried:
Setting the code page to 1200, 1208, or 1252, using both the DB2CODEPAGE environment variable as well as the connection string CodePage parameter; nothing changed the error message
Verified all software (DB2, DB2 DSDRIVER, .NET provider) are v11.5
Verified I can connect and run queries with db2cli.exe
Now what?
Is there somewhere I can/should be setting the DB2 server type? Eg, z/OS vs LUW? Note that I'm not using EntityFramework, just directly executing Commands on that Connection object (though the error comes before then).
We have solved the problem. There were two changes to make, which definitely complicated things.
We did need to set the DB2CODEPAGE environment variable to 1208
We were using the CurrentSchema connection string parameter to set the prefix for our SQL queries, but the prefix wasn't the actual schema, which broke the connection even when the right codepage was set, without a useful error message on the client. We removed that parameter and manually set the table prefix on our SQL queries.
Making both those changes got the application working.
Connecting to the local Docker instance had worked because I had set an actual schema for that prefix, not realizing the prod instance was configured differently.
After a few years, I have returned to writing in C# and I am really struggling here - I would like to have my app to have a local SQL database. I have added Service-based database and "Database1.mdf" was added to my project. I created a table and added some data just to see if it is working but I cannot connect to it. I tried numerous connection strings with no success (Server not accessible).
Do I need to run something else in the background? I thought that I might have a local database and with .NET client I can access it, and I hoped it would work whenever I bring my application (also not requiring any SQL server running). Is that wrong?
If you don't require any SQL server, take a look at SQLite. This is lite SQL database engine. Database is just one file. C# has a great library to SQLite on NuGet: https://www.nuget.org/profiles/mistachkin
SQLite is widely used, event in Android (as a native db engine).
here is what i use to connect. it appears as a Data Connection in Server Explorer.
string con2 = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=" + Application.StartupPath + "\\jobfile_2017.mdf;Integrated Security=True;Connect Timeout=30";
when i first started working with these, i used this source 1
it works on PC's that i have nothing installed (not even office) but as i said i'd be interested to know of any shortcomings of this method
I experiencing same problem and decided to move mdf file to static c:\db directory. Connection string was changed to incorporate new file location (AttachDbFile).
But AttachDbFile has some issues also (by some reason one table in db is inaccesible and error is access denied).
So I decided to move to Sqlite. LocalDb has many issues to work with. I read good note to resolve problem: in command line stop/remove/start name of instance. But it nuissance.
Wish you good luck to work with these db files.
I am attempting to connect to DB2 database from C#.Net. The connection string i used is:
Provider=DB2OLEDB;Cache Authentication=True;Password=xxxxxxx;Persist Security Info=True;User ID=xxxxxx;Initial Catalog=xxxxxxxx;Data Source=xxxxxxxxx;Defer Prepare=False;Derive Parameters=False;Network Transport Library=TCPIP;Host CCSID=37;PC Code Page=1252;Network Address=xxxxxxxxx;Network Port=446;Package Collection=CDATA;Default Schema=CDATA;DBMS Platform=DB2/AS400;Process Binary as Character=False;Connection Pooling=True;Units of Work=RUW
On executing the ExecuteReader(), i keep getting the runtime exception:
The 'DB2OLEDB' provider isn't registered on the local system.
I have already included the reference to library "System.Data.OleDb" in my class.
The DB2 resides on a different server and i don't have any db2 instance on my local machine. How do I solve this difficulty?
Can someone please help me with fixing this error, is it any other dll reference that I am missing? I am assuming I do not need to get any DB2 client installaed on my machine in order to be fixing this issue, could it be done by just a dll reference?
Change the provider name from "DB2OLEDB" to "IBMDADB2" and see also here: IBM Knowledge Center
I am working on application which uses Sybase database and entity framework for accessing database. I am trying to make application to open connection itself and close it. I created model using Sybase database file and now connecting to it to get data. But when I try to get data I get exception "The underlying provider failed to Open".
Here is my code.
var connectionString = metadata=res://*/SampleModel.csdl|res://*/SampleModel.ssdl|res://*/SampleModel.msl; +
provider=iAnywhere.Data.SQLAnywhere; +
provider connection string="DBF=D:\SampleDatabase.db;UID=DBA;PWD=sql"
var dataContext = new SampleContext(connectionString);
var contacts = dataContext.Contacts; --> Here I get this exception.
Note: If I create a DSN in ODBC and use DSN instead of giving filename it gives me Not connected to a database exception. If I open this connection and do not close it, then it works fine. But I don't want to create DSN entry and open it manually. I want my program to do this.
There was problem with my version of Sybase. I was using 3840 build of Sybase 12. I removed it and installed 3769 version and it worked fine. On different forums I found out that latest (3840) is having problems.
I'm running Visual Studio Developer Preview 2011 on a Windows 7 x64 machine.
I'm a beginning to learn C# and am having difficulties connecting to a database. I created a database with MS Access and created a connection by using the Connect to a Database option.
Here is the connection string
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\USER\Documents\BlankDB.mdb
I am following this tutorial
I added the variable masterConnectionString to the Project Settings and initialized it with the value of the connection string.
The program compiles but at run-time I get the following error
A first chance exception of type 'System.ArgumentException' occurred in System.Data.dll
Additional information: Keyword not supported: 'provider'. After this the program terminates.
If I remove the provider part from the string the following exception is thrown.
Additional information:
A network-related or instance-specific error occurred while establishing a connection to SQL Server.
The server was not found or was not accessible.
Verify that the instance name is correct and that SQL Server is configured to allow remote connections.
(provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I have been trying for sometime now and this is really frustrating. Is there some other easier method of connecting to databases in C# ? Is it possible to create a SQL Server database from within Visual Studio?
Here is the code that I use to connect to the data base.
static void TryCreateTable()
{
using (SqlConnection con = new SqlConnection(DogsDB.Properties.Settings.Default.BlankDBConnectionString))
{
con.Open();
try
{
using (SqlCommand command = new SqlCommand("CREATE TABLE Dogs1 (Weight INT, Name TEXT, Breed TEXT)", con))
{
command.ExecuteNonQuery();
}
}
catch
{
Console.WriteLine("Table couldn't be created.");
}
}
}
You are following a tutorial for sql server. To connect to your MS Access db, your connection code should look something like this:
OleDbConnection sqlConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Users\\USER\\Documents\\BlankDB.mdb");
Make sure the backslashes are escaped.
Then you can do
try{
sqlConn.Open();
OleDbCommand command = new OleDbCommand("CREATE....", sqlConn);
command.CommandType = CommandType.Text;
command.ExecuteNonQuery();
}
catch(InvalidOperationException ioe)
{
....
}
catch(OleDbException ode)
{
....
}
sqlConn.Close();
That's an OleDB connection string, not a SQL Server connection string.
You need to use it with an OleDbConnection.
If you want to use SQL Server rather than Access, you can create a database using SQL Server Management Studio or VS's Server Explorer.
You can then connect to it using a SQL Server connection string.
You can see sample connection strings here.
There are several reasons you are getting this error.
1) The reference website is to use SQL Server database not Access.
2) You are running on a x64 operating system which means the following is true.
The Microsoft OLE DB Provider for Jet and the Jet ODBC driver are available in 32-bit versions only. You can't run them in 64 bit mode.
For example, you have a 32-bit application that uses the Microsoft OLE DB Provider for Jet. If you migrate the application to run in the
64-bit mode, the application cannot connect to the data source by
using the Microsoft OLE DB Provider for Jet. This issue occurs because
the application requires a 64-bit version of the Microsoft OLE DB
Provider for Jet. Note also that a website can be either an 32 bit or
64 bit application.
So the solution is use the following:
http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=13255
If you run a program in a 64 bit environment and need to utilize jet
to open an access, excel or text file there are several options to
make this work. •Run the program in WoW64 mode (emulates 32-bit on 64
bit systems). This will make the 32 bit drivers work. •If the
application is an web app hosted on IIS 7 you can choose to configure
the web sites application pool to run in 32-bit mode. •With the new
Office 2010, there will be new drivers coming, "2010 Office System
Driver", which will be provided as booth 32-bit and 64-bit versions.
You can use these drivers to let you application connect to Access,
Excel and text-files in a 64 bit environment, utilizing the new 64 bit
drivers. The provider name is "Microsoft.ACE.OLEDB.14.0". You don't
need to buy or install the Office suite, the components are available
as a separate download.
If you want additiona assistance you will have to provide the code your using.
You should update the code in your question AFTER you have researched and installed the linked library.