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
DOK.. 8
获得连接字符串后,可以使用打开连接Connection.Open()
.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
在关闭连接之前的任何时候Connection.Close()
,您都可以使用它来检查其状态Connection.State
.它返回枚举中的值,例如ConnectionState.Open
.
获得连接字符串后,可以使用打开连接Connection.Open()
.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
在关闭连接之前的任何时候Connection.Close()
,您都可以使用它来检查其状态Connection.State
.它返回枚举中的值,例如ConnectionState.Open
.