An error occurred When i use C# to connect mysql in first time.
the error message is:
Connection open error . Authentication to host 'localhost' faied.
...but in the second time,it become normal.
this is my connect string
DefaultConnectionString": "Server=localhost;Database=DatabaseName;Uid=root;Pwd=123456;
if you add:
ConnectionReset=True;
.this command is supposed to make one more trip and reset the connection.
I have a C# Application which would access a MySQL server on another computer. I am trying to do it via IP. Here is my Connection String :
result = "server =66.45.233.226; user id=testcampuscrm; password =Daph$5656; database=testcampuscrm; convert zero datetime=true; ";
getting error this
Access denied for user 'testcampuscrm'#'66.45.232.178' (using
password: YES)
My code is anther hosting and mysql database anther hostig please help us. Thanks
There is multiple things you have to take into consideration while accessing mysql from another machine some them are -
Assuming you did write correct code
1.Change mysql config (my.ini) to receive packets from all IP
2.Add firewall Exception for port 3306 on machine where Mysql is Hosted
3.User name password is Correct and granted proper privileges.
PS:-Do not share server credentials on public forums
I see several answers to problems similar to mine, but I don't know enough to adapt those answers to my problem. So, with apologies for what is probably a duplicate question, here goes:
I'm trying to connect to a Microsoft SQL 2014 database on my local machine from a ASP.NET application. The code is:
oCN = new OleDbConnection(connectionString);
With a connectionString of:
Provider=SQLNCLI11; Server=FLIPPY\SQLEXPRESS; Trusted_Connection=yes;
Database=FingerTipDisplay; User Id=<my user id>; Password=<my password>
oCN is as follows after the call to new OleDbConnection():
- oCN {System.Data.OleDb.OleDbConnection} System.Data.OleDb.OleDbConnection
CanRaiseEvents true bool
ConnectionString "Provider=SQLNCLI11; Server=FLIPPY\\SQLEXPRESS; Trusted_Connection=yes; Database=FingerTipDisplay; User Id=<my user id>; Password=<my password>" string
ConnectionTimeout 15 int
Container null System.ComponentModel.IContainer
DataSource "" string
Database "" string
DbProviderFactory null System.Data.Common.DbProviderFactory
DesignMode false bool
+ Events {System.ComponentModel.EventHandlerList} System.ComponentModel.EventHandlerList
Provider "SQLNCLI11" string
+ ServerVersion 'oCN.ServerVersion' threw an exception of type 'System.InvalidOperationException' string {System.InvalidOperationException}
Site null System.ComponentModel.ISite
State Closed System.Data.ConnectionState
+ Static members
+ Non-Public members
I believe my SQL server is running correctly:
I can't get SQL Server Agent to start, and am not sure if that's causing my problem or not. From other replies I've ensured TCP/IP is enabled:
This is my database structure:
and I think that the user name and password I'm connecting has the right permissions from the dbo schema:
I've checked the SQL Server logs and don't see anything that looks like a failed login attempt, and I don't know where to look in the OleDbConnection object for feedback on why the connection failed. I'm working on someone else's code, so I'm reluctant to use SqlConnection() since I don't know the implications for the rest of the app.
I'm guessing that the problem is in the connection string, but I don't know what to use for that. I've tried SQLOLEDB as the provider, and I've tried using Initial Catalog instead of Database.
Thanks in advance for your help.
Update:
Thanks for all the help so far. oCN.Open() was throwing an OleDbException immediately, and it was:
"Login failed for user 'riehlj2002#gmail.com'."
I made some changes to the connection string based on the advice below...this is what it looks like right now:
Provider=SQLNCLI11; server=localhost; DataSource=localhost\SQLEXPRESS; Database=FingerTipDisplay; user id=<my user id>; password=<my password>
Now it doesn't throw the exception right away, but it still throws it. This is the exception I get:
{"Login timeout expired\r\nA network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online.\r\nNamed Pipes Provider: Could not open a connection to SQL Server [2]. \r\nInvalid connection string attribute"}
A few things I notice.
First, if I change server to localhost\SQLEXPRESS I get an immediate exception telling me that I have an invalid connection string attribute, so the advice in this link doesn't work for me.
Second, it doesn't seem to matter whether I use localhost or my machine name...it does the same thing.
Third, I was surprised to see something in there about the named pipes protocol. I went into the SQL Server Configuration Manager and enabled that protocol...it didn't make a difference.
Fourth, it doesn't make a difference whether I specify DataSource or not in terms of the exception, but intuitively it seems like I have to specify the server instance somewhere so I've left it in.
Fifth, if I change the provider to SQLOLEDB I get a different exception: {"[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied.\r\nInvalid connection string attribute"}, so I think I'm on the right track with SQLNCLI11.
Sixth, in the OleDbConnection object the DataSource and Database properties are both empty strings despite their being specified in the connection string.
Finally, the very last part of the exception I'm getting now talks about an invalid connection string attribute, but I removed each one in turn and either got the same exception or got another one that I've already described.
Again, thanks for the help.
You are using Trusted_Connection=yes but specifying a username and password. It's either one or the other, I don't think you can do both in the same connection string (not sure if that'd raise any errors, but the supplied user and password would be at least ignored, for sure).
In your case, since you are using a user and a password, you'd need to set Trusted_Connection to no (or false), or just not set it (it should be false by default)
OK, I found the problem. My original connection string wasn't finding the database, so I got no additional information in the server logs. I changed the connection string to:
Provider=SQLNCLI11; server=localhost\SQLEXPRESS; Database=FingerTipDisplay; user id=<my user id>; password=<my user id>
And then I found in the server log that it was configured to use Windows authentication only. I used this link to allow SQL server authentication, and all is now well. Your answers got me going in the right direction...thanks.
I am creating desktop application in c# but i wont to use Online Database created in mysql.
String mysqlConnectionString = "Server=216.14.120.105;Database=xxx_keys;UID=xxx_root;Password=xxx;Port=3306";
MySqlConnection connection = new MySqlConnection(mysqlConnectionString);
connection.Open();
this is the code i am using but i got an error unable to access host.
where i am wrong and if you have any proper code or details then give me.
If this is a MySQL database in local server user "localhost" for server IP as georgi-it also told. But if this is an external database first try to open a telnet connection on dos-prompt to see if there is some firewall block or something like that:
telnet 216.14.120.105 3306
if you don't get an error message and see a blank page then it means you can reach mysql server
What connection string should I use if SSMS connects to it using simply machine name, without instance name?
I mean it connects using the following string: PCName
I used to connect using PCName/SQLExpress. I cannot set correct connection string in my app in order to connect app to database on this machine.
How can I check what data source I should use? I've checked in Sql Server configuration that server instance named as SQLEXPRESS.
So I tried data source as:
.\SQLEXPRESS
PCName\SQLEXPRESS
.
I'm trying to connect to a service-based database, located in my app folder. So I'm using the following connection string:
data source=PCName;attachdbfilename=|DataDirectory|\spareparts.mdf;integrated security=true;user instance=true;multipleactiveresultsets=true;App=EntityFramework;
If SSMS connects via PCName then your application should be able to use Data Source=PCName. However it depends on whether your application is on the same machine as SSMS or not. If on a different machine it might not be able to connect for a variety of reasons. We can't speculate what the problem might be if all you do to describe the issue is "It won't connect" - what does that mean? Do you get an error message? If so, what is it? Make sure:
SQL Browser service is started
TCP/IP is enabled
Add Network=DBMSSOCN; to the connection string
You've also tried the IP address in addition to PCName
Firewall isn't blocking the SQL Server port