I am trying to connect to a SQL Server database in my website. I have created a database from Add -> Add New Item -> SQL Server database. The name of my database file is database.mdf.
I have created a ConnectionString:
<connectionStrings>
<add name="Khulna_website"
connectionString= "Server=(localDB)\\v11.0;Integrated Security=SSPI;Database=Database.mdf;"
providerName="System.Data.SqlClient" />
</connectionStrings>
My first question is, when I open a database that way, is it necessary to add a connection string? Asking that because I can already see a green connection line on the side of the database.
Then, how do I connect it on my C# code?
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["RegistrationConnectionString"].ConnectionString);
conn.Open();
The question is, what do I add on ["RegistrationConnectionString"] part? Should I give the name of my ConnectionString? Am I missing any point here? I am completely new here. Any help would be highly appreciated.
Yes, in order to connect to a database - you do need some form of a connection string - one way or another. It's typically considered a best practice to put those connection strings into a config file, so you can modify it without changing your code.
To retrieve the actual connection string from the config, you need to use the name=.... to you gave it in the config file:
<add name="Khulna_website"
*************** this is the **name** of your connection string
Retrieve it like this:
string conStr = ConfigurationManager.ConnectionStrings["Khulna_website"].ConnectionString;
************** same name again
and then use it to create your connection object to the database:
SqlConnection conn = new SqlConnection(conStr);
Put the name of the connection string which is Khulna_website instead of RegistrationConnectionString
I am working on a MVC 4 web site. It should allow the user to select which database to be connected with depending on user selection from the View. All the databases have the same table structure and schema etc.
I have a database ConnectionString defined in the Web.config file that allows for connection to the first database.
<connectionStrings>
<add name="DBConnectionString" connectionString="Data Source=DATABSE_SERVER;Initial Catalog=DATABASE_NAME;Persist Security Info=True;User ID=USERNAME;Password=PASSWORD" providerName="System.Data.SqlClient" />
</connectionStrings>
I also used Linq DataContext to initialize connection to the database. Table mappings were all automatically generated by Linq to SQL in MVC 4.
public NEMP_DataDataContext() :
base(global::System.Configuration.ConfigurationManager.ConnectionStrings["DBConnectionString"].ConnectionString, mappingSource)
{
OnCreated();
}
What is the best way to achieve this?
In LINQ to SQL, you just create the Context with the connection string:
DataContext myContext = new DataContext(customConnectionString);
You don't need to worry about closing them or anything. SQL Server is handling all that for you. So you simply adjust the connection string slightly (Database Name) and create a new context based on whatever variable in every page you need to use the Context.
You can use the ChangeDatabase method of SqlConnection
See MSDN.
First of all, you should have a storage to get all of the database connections.
Maybe the storage is a xml file or a simple database.
But you need to implement how to get the connection strings.
If you have used EntityFramework for your dataconext in your applicaiton.
You could have a constructor like the folowing code:
public ApplicationDbContext(string nameOfConnection)
: base(nameOfConnection)
{
this.Configuration.ProxyCreationEnabled = true;
this.Configuration.LazyLoadingEnabled = true;
}
Please invoke the 1 and get the nameOfConneciton, then invoke 2 to initialize the DbContext.
I'm not sure if I understand your question fully. But I assume you ask us that you want to let the user select the database they want to connect to. Then set the connection string.
Here's my solution, for example if you have 5 database to let user to select. You write those 5 connection string into web.config. Then make something like a drop down list or radio button that let's user to select database. And then make a if statement. For example if the first radio button is selected then
String connection string=connection.string["the name of connection string in web.confug"];
I hope this help you
This line:
WebSecurity.InitializeDatabaseConnection(connectionStringName: "DefaultConnection", userTableName: "UserProfile", userIdColumn: "UserID", userNameColumn: "UserName", autoCreateTables: true);
Is throwing:
'System.ArgumentException' occurred in System.Data.dll but was not handled in user code
Additional information: Keyword not supported: 'metadata'.
My connection string is:
add name="DefaultConnection" connectionString="metadata=res://*/TalyllynModel.csdl|res://*/TalyllynModel.ssdl|res://*/TalyllynModel.msl;provider=System.Data.SqlClient;provider connection string="data source=***********;initial catalog=********;persist security info=True;user id=*********;password=********;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.SqlClient" /></connectionStrings>
Not sure where it is im going wrong.
The string you passed is not a valid database connection string, it's an EF connection string that contains a SQL Server connection string in its provider connection string parameter. WebSecurity.InitializeDatabaseConnection expects a valid database connection string
To avoid parsing the connection string yourself, you can use the EntityConnectionStringBuilder class to parse the string and retrieve the database connection string from its ProviderConnectionString property
When this happened to me it was because the connection string had:
providerName="System.Data.SqlClient"
but it should be:
providerName="System.Data.EntityClient"
because as was said by the other answer, it is an EF connection string.
Just to add another possibility (which I encountered) - which might be the case if you're developing/maintaining an Azure WebApp, using a connection string saved in Azure's Application Settings.
Beside each connection string in the Application Settings is a dropdown for the connection string type - it's very easy to forget to set this to 'Custom' for Entity Framework values and leave it at the default (SQL Database) - which also causes the above error.
Here's some code I use, to extract the database name & server name from a connection string.
Notice how it checks if it's an Entity Framework connection string, and if so, it extracts the "provider connection string" part of that, which can then be passed into SqlConnectionStringBuilder:
If I didn't do this, I'd get that nasty "Keyword Not Supported: Metadata" error.
if (connectionString.ToLower().StartsWith("metadata="))
{
System.Data.Entity.Core.EntityClient.EntityConnectionStringBuilder efBuilder = new System.Data.Entity.Core.EntityClient.EntityConnectionStringBuilder(connectionString);
connectionString = efBuilder.ProviderConnectionString;
}
SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(connectionString);
DatabaseServer = builder.DataSource; // eg "MikesServer"
DatabaseName = builder.InitialCatalog; // eg "Northwind"
I'm going to throw out another answer, just in case someone else runs into this through the same weird scenario as I did.
To start with, as others have said, ADO connection strings and EF connection strings are different.
An ADO connection string contains a number of semicolon-separated fields, which can very from one connection type to another, but you usually see "data source=xxx", "initial catalog=yyy", etc. You will not see "metadata=zzz".
An EF connection string has the same structure, but it has a "metadata=zzz" and a "provider connection string=www", where "www" is an escaped ADO connection string.
So a normal format for an ADO connection string is:
data source=myserver;
initial catalog=mydatabase;
Persist Security Info=True;
User ID=myusername;
Password=mypassword;
MultipleActiveResultSets=True
While a normal format for an EF connection string is:
metadata=res://*/MyDbContext.csdl|
res://*/MyDbContext.ssdl|
res://*/MyDbContext.msl;
provider=System.Data.SqlClient;
provider connection string="
data source=myserver;
initial catalog=mydatabase;
Persist Security Info=True;
User ID=myusername;
Password=mypassword;
MultipleActiveResultSets=True;
application name=EntityFramework
"
Most folks who are running into this problem seem to have cut an EF connection string and pasted it into a place that needed an ADO connection string. In essence, I did the same thing, but the process wasn't as clear as all that.
In my case, I had a web application that used EF, so its web.config properly contained EF connection strings.
I published a deployment package, and the process prompts you for the connection strings to be used when deploying. These are stored in the deployment package's generated SetParameters.xml file.
I cut and pasted the EF connection strings into the publish dialog's entry fields.
I deployed the web application, tried to access it, and got the "Keyword not supported: metadata" error.
What I didn't realize is that MS's publish tool expected an ADO connection string, and that given it it would construct an EF connection string.
The result was that SetParameters.xml and my deployed web.config had connection strings that looked like this:
metadata=res://*/MyDbContext.csdl|
res://*/MyDbContext.ssdl|
res://*/MyDbContext.msl;
provider=System.Data.SqlClient;
provider connection string="
metadata=res://*/XxDbContext.csdl|
res://*/XxDbContext.ssdl|
res://*/XxDbContext.msl;
provider=System.Data.SqlClient;
provider connection string="
data source=myserver;
initial catalog=mydatabase;
Persist Security Info=True;
User ID=myusername;
Password=mypassword;
MultipleActiveResultSets=True;
application name=EntityFramework
"
""
In other words, the embedded provider connection string was an EF connection string and not an ADO connection string, so when EF tried to use it to connect to the database, it generated this error.
In other words, when you are pasting the connection strings into the publish dialogues, you need to paste a ADO connection string, not an EF connection string, even if what you have in the web.config you are copying from is an EF connection string.
You can extract an ADO connection string from the provider connection string field of an EF connection string, and that's what you will need, if you're using the same connection in the deploy as you did in local development.
For use in Azure Application Settings => Connection Strings:
If the connection string is generated by EF-designer be sure to replace &qout; with " in the string.
Check that provider=System.Data.SqlClient
Choose Type Custom in the dropdown
If the connection is for a model (Entity Framework) ensure that correct path to your model is used
Ex: A model "MyWebRoot/Models/MyModel.edmx" is configured as: metadata=res:///Models.MyModel.csdl|res:///Models.MyModel.ssdl|res://*/Models.MyModel.msl;
Hi,
In my opinion, the connection string for ADO.NET (in this
caseSqlConnection) can't use 'metadata. You're using the one specific
for Entity Framework. The ADO.NET one should be something like:
"data source=KAPS-PC\KAPSSERVER;initial catalog=vibrant;integrated security=True"
So, to sum it up, you need two separate connection strings, one for EF
and one for ADO.NET.
Souce: http://forums.iis.net/post/2097280.aspx
For Azure Web App, Connection string type has not "System.Data.EntityClient", Custom works good.
Dry This,
Remove metadata Info from your ConnectionString.
Change this.
<add name="DefaultConnection" connectionString="metadata=res://*/TalyllynModel.csdl|res://*/TalyllynModel.ssdl|res://*/TalyllynModel.msl;provider=System.Data.SqlClient;provider connection string="data source=***********;initial catalog=********;persist security info=True;user id=*********;password=********;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.SqlClient" /></connectionStrings>
To
<add name="DefaultConnection" connectionString="data source=***********;initial catalog=********;persist security info=True;user id=*********;password=********;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.SqlClient" /></connectionStrings>
Before i give My Solution let me explain something , I got this problem too , im using EntityFramework and Ado.net you cant use Entity framework Connection string in ADo and vice versa , so what i did was in the Web.config file i left the EF Connection string(Metadata one)
and in the Controller for ADO i Added the connection string which i got from the database(properties). add the ADO string like this :
SqlConnection sql = new SqlConnection();
sql.ConnectionString = #"Data Source=.\alienbwr;Initial Catalog=ABTO_POS;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False";(dont use my string)
An old post but my solution,
Unfortunately these didn't solve it for me using Azure Functions talking to a separate project (class library) with an EDMX.
I had to edit the Context.CS class constructor replacing the
: base ("Entities")
with
: base (ConfigurationManager.ConnectionStrings["Entities"].ConnectionString)
Hopefully this might help someone else in need.
Check in this place
<add name="ConnectionString" connectionString="Data Source=SMITH;Initial Catalog=db_ISMT;Persist Security Info=True;User ID=sa;Password=#darksoul45;MultipleActiveResultSets=True;Application Name=EntityFramework"
providerName="System.Data.SqlClient" />
As you can see there's a two connection string one for ADO and another for the Login System or whatever you want. In my case, ConnectionString is for Login system so I've used that in:-
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
SqlCommand cmd = null;
SqlDataReader dr = null;
protected void Page_Load(object sender, EventArgs e)
How do I change the connection string in a code first entity framework/MVC application? I'm trying to transfer it to a live site, but it overlooks web config values and still references my local version of the database.
Here is the connection string section of my web.config:
<add name="MembershipConnectionString" connectionString="Data Source=192.168.1.43;Initial Catalog=Website.Models.IntranetApplication;User Id=[UserName];Password=[Password];timeout=30" />
<add name="WebsiteConnectionString" connectionString="Data Source=192.168.1.43;Initial Catalog=Website.Models.IntranetApplication;User Id=[UserName];Password=[Password];timeout=30" />
<add name="Entities" connectionString="metadata=res://*/Models.IntranetModel.csdl|res://*/Models.IntranetModel.ssdl|res://*/Models.IntranetModel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=192.168.1.43;Initial Catalog=Website.Models.IntranetApplication;User Id=[UserName];Password=[Password];MultipleActiveResultSets=True"" providerName="System.Data.EntityClient" />
I'm not sure if the Entities string has any relevance, as I used Code First entity framework, and I think that only appeared when I tried to create an edmx file (although I ended up just deleting it). The Entities connection string has sat commented out so I don't think it's used.
I want entity framework to read the "WebsiteConnectionString", but it seems to want to use the local connection string, but I can't even see where that is set. How do I change it?
The connection string or its name can be passed to constructor of DbContext. If you are using default constructor it searches for the connection string with the same name as the name of your derived context class and if it doesn't find it, it uses this one:
Data Source=.\SQLEXPRESS; Integrated Security=True; MultipleActiveResultSets=True
With database name same like your context class.
I am developing an asp.net application which I have hosted on an IIS server. To open a connection I use:
SqlConnection con = new SqlConnection("Server = INLD50045747A\\SQLEXPRESS;
Database = MyDatabase;User ID = sa; Password = Welcome1; Trusted_Connection = False;");
con.Open();
Is it possible to store this connection string somewhere so that I don't need to write in every aspx.cs file? I am using MSSQL database.
I'm facing an issue which says:
The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached
I read somewhere which asks me to increase the maximum connection pool to 100. Will it affect the performance of my application?
You probably aren't closing your open connections propertly.
Increasing the "pool size" is like putting a bigger bucket under a waterfall - it will help, but barely.
Try and locate areas where something like this is happening:
con.Open();
Ensure that if it's not in a try/catch, that it is in one, and that it includes a finally statement.
try {
con.Open();
//several other data base releated
//activities
} catch (Exception ex) {
// do something
} finally {
con.Close();
}
Also, to avoid having to use the finally block, you can just wrap the SqlConnection in a using statement.
using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["yourKey"].ConnectionString))
{
// write your code here
}
In regards to your question about connection string, yes store it in your web.config
<connectionStrings>
<add name="name" connectionString="Data Source=;Initial Catalog=;User ID=sa;password=;Persist Security Info=True;Connection TimeOut=20; Pooling=true;Max Pool Size=500;Min Pool Size=1" providerName="System.Data.SqlClient"/>
</connectionStrings>
Store it in the web.config file, in the connectionStrings section:
<connectionStrings>
<add name="name"
connectionString="Data Source=;Initial Catalog=;User ID=sa;password=;Persist Security Info=True;Connection TimeOut=20; Pooling=true;Max Pool Size=500;Min Pool Size=1"
providerName="System.Data.SqlClient"/>
</connectionStrings>
And then you will be able to access this in your code...
ConfigurationManager.ConnectionStrings["name"].ConnectionString
you can do using also
it will automatically disposes the object
if you use "using" there is no need of con.close and all
using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["yourKey"].ConnectionString))
{
// write your code here
}
Store the connection string in the web.config files. you can find numerous examples. Check this for the properties. http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring%28v=vs.71%29.aspx
Thanks
Shankar
Use the Help of Both
try
{
con.Open();
}
catch(Exception ex)
{
if(con.State== ConnectionState.Open)
con.Close();
}
finally
{
con.Close();
}
and also add the Connection String in Web.Config, under Configuration. This will help you.
Yes, store it in the web.config file but make sure that if there is an error it doesn't display the content of the web.config file to the user (thus showing the world your password.)
If you use that same connection string in a lot of applications you could consider writing a service to provide the connection strings, that way you only have to change them in one place.
The best option is to use typed settings.
Open your project properties.
Go to Settings tab.
Add new setting, for example MainConnectionString, select setting type (ConnectionString). In the value insert your connection string or hit '...' button to bring a dialog to build connection string.
Now you can reference your connection string in the code like this:
Settings.Default.MainConnectionString
If you open your config file you will see
<configuration>
<connectionStrings>
<add name="WebApplication1.Properties.Settings.MainConnectionString"
connectionString="Data Source=localhost;Initial Catalog=AdventureWorks;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
You can have this connection string
specified:
for one web site in its own web.config.
for a group of web sites
for all web sites on a box: in machine scope web.config.
for all application on a box: in the machine.config.
This can be convenient if you have a lot of applications that connect to the same db and are installed on one box. If db location changes you update just one file machine.config, instead of going to each application's config file.