SqlConnection Constructors
Definition
Important
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Overloads
SqlConnection() |
Initializes a new instance of the SqlConnection class. |
SqlConnection(String) |
Initializes a new instance of the SqlConnection class when given a string that contains the connection string. |
SqlConnection(String, SqlCredential) |
Initializes a new instance of the SqlConnection class given a connection string, that does not use |
SqlConnection()
Initializes a new instance of the SqlConnection class.
public:
SqlConnection();
public SqlConnection ();
Public Sub New ()
Examples
The following example creates and opens a SqlConnection.
using Microsoft.Data.SqlClient;
class Program
{
static void Main()
{
OpenSqlConnection();
Console.ReadLine();
}
private static void OpenSqlConnection()
{
string connectionString = GetConnectionString();
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
Console.WriteLine("ServerVersion: {0}", connection.ServerVersion);
Console.WriteLine("State: {0}", connection.State);
}
}
static private string GetConnectionString()
{
// To avoid storing the connection string in your code,
// you can retrieve it from a configuration file, using the
// System.Configuration.ConfigurationManager.ConnectionStrings property
return "Data Source=(local);Initial Catalog=AdventureWorks;"
+ "Integrated Security=SSPI;";
}
}
Remarks
When a new instance of SqlConnection is created, the read/write properties are set to the following initial values unless they are specifically set using their associated keywords in the ConnectionString property.
Properties | Initial value |
---|---|
ConnectionString | empty string ("") |
ConnectionTimeout | 15 |
Database | empty string ("") |
DataSource | empty string ("") |
You can change the value for these properties only by using the ConnectionString property. The SqlConnectionStringBuilder class provides functionality for creating and managing the contents of connection strings.
Applies to
SqlConnection(String)
Initializes a new instance of the SqlConnection class when given a string that contains the connection string.
public:
SqlConnection(System::String ^ connectionString);
public SqlConnection (string connectionString);
new Microsoft.Data.SqlClient.SqlConnection : string -> Microsoft.Data.SqlClient.SqlConnection
Public Sub New (connectionString As String)
Parameters
- connectionString
- String
The connection used to open the SQL Server database.
Exceptions
The supplied connection string argument failed ConnectionString validation.
Examples
The following example creates and opens a SqlConnection.
using Microsoft.Data.SqlClient;
class Program
{
static void Main()
{
OpenSqlConnection();
Console.ReadLine();
}
private static void OpenSqlConnection()
{
string connectionString = GetConnectionString();
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
Console.WriteLine("State: {0}", connection.State);
Console.WriteLine("ConnectionString: {0}",
connection.ConnectionString);
}
}
static private string GetConnectionString()
{
// To avoid storing the connection string in your code,
// you can retrieve it from a configuration file, using the
// System.Configuration.ConfigurationSettings.AppSettings property
return "Data Source=(local);Initial Catalog=AdventureWorks;"
+ "Integrated Security=SSPI;";
}
}
Remarks
When a new instance of SqlConnection is created, the read/write properties are set to the following initial values unless they are specifically set using their associated keywords in the ConnectionString property.
Properties | Initial value |
---|---|
ConnectionString | connectionString |
ConnectionTimeout | 15 |
Database | empty string ("") |
DataSource | empty string ("") |
You can change the value for these properties only by using the ConnectionString property. The SqlConnection class provides functionality for creating and managing the contents of connection strings.
Applies to
SqlConnection(String, SqlCredential)
Initializes a new instance of the SqlConnection class given a connection string, that does not use Integrated Security = true
and a SqlCredential object that contains the user ID and password.
public:
SqlConnection(System::String ^ connectionString, Microsoft::Data::SqlClient::SqlCredential ^ credential);
public SqlConnection (string connectionString, Microsoft.Data.SqlClient.SqlCredential credential);
new Microsoft.Data.SqlClient.SqlConnection : string * Microsoft.Data.SqlClient.SqlCredential -> Microsoft.Data.SqlClient.SqlConnection
Public Sub New (connectionString As String, credential As SqlCredential)
Parameters
- connectionString
- String
A connection string that does not use any of the following connection string keywords: Integrated Security = true
, UserId
, or Password
; or that does not use ContextConnection = true
.
- credential
- SqlCredential
A SqlCredential object. If credential
is null, SqlConnection(String, SqlCredential) is functionally equivalent to SqlConnection(String).
Exceptions
The supplied arguments failed validation, including ConnectionString validation.