我有以下模块,我想测试连接。如何测试连接是否有效?你能否回答一下你的答案:
Imports System.Data.SqlClient
Module Module1
Sub Main()
' Create a new SqlConnectionStringBuilder and
' initialize it with a few name/value pairs:
Dim builder As New SqlConnectionStringBuilder(GetConnectionString())
' The input connection string used the
' Server key, but the new connection string uses
' the well-known Data Source key instead.
Console.WriteLine(builder.ConnectionString)
' Pass the SqlConnectionStringBuilder an existing
' connection string, and you can retrieve and
' modify any of the elements.
builder.ConnectionString = _
"server=http://sql.example.com;user id=******;" & _
"password=***********;"
' Now that the connection string has been parsed,
' you can work with individual items.
Console.WriteLine(builder.Password)
builder.Password = "new@1Password"
builder.AsynchronousProcessing = True
' You can refer to connection keys using strings,
' as well. When you use this technique (the default
' Item property in Visual Basic, or the indexer in C#)
' you can specify any synonym for the connection string key
' name.
builder("Server") = "."
builder("Connect Timeout") = 1000
' The Item property is the default for the class,
' and setting the Item property adds the value to the
' dictionary, if necessary.
builder.Item("Trusted_Connection") = True
Console.WriteLine(builder.ConnectionString)
Console.WriteLine("Press Enter to finish.")
Console.ReadLine()
End Sub
Private Function GetConnectionString() As String
' To avoid storing the connection string in your code,
' you can retrieve it from a configuration file.
Return "Server=(local);Integrated Security=SSPI;" & _
"Initial Catalog=AdventureWorks"
End Function
End Module
答案 0 :(得分:8)
获得连接字符串后,可以使用Connection.Open()
打开连接。
您可以在try-catch块中执行此操作,以捕获尝试在此处打开connection.enter代码时发生的任何错误
在您关闭与Connection.Close()
的连接之前的任何时候,您都可以使用Connection.State
检查其状态。这会返回枚举中的值,例如ConnectionState.Open
。
答案 1 :(得分:2)
创建一个连接对象,然后将其打开