使用 VB .net 从 Sqlserver db 检索记录答案

【问题标题】：Retrieve records from Sqlserver db with VB .net使用 VB .net 从 Sqlserver db 检索记录
【发布时间】：2012-04-27 16:06:47
【问题描述】：

这是我的工作：

Dim connstr = "data source=mydatasource;initial catalog=gcs_dw;persist security   info=True;user id=myuser;password=mypassword;Asynchronous Processing=True"
Dim sqlquery = "SELECT * FROM Customer WHERE CITY = 'Anytown'"
Dim connection As SqlConnection = New SqlConnection(connstr)
connection.Open()

Dim command As SqlCommand = connection.CreateCommand()
command.CommandText = sqlquery
Dim reader As SqlDataReader = command.ExecuteReader()
reader.Read()
Console.WriteLine(reader.ToString)
connection.Close()
Console.Read()

如您所见，我正在尝试将查询结果显示到命令行，目前它显示的只是“System.Data.SqlClient.SqlDataReader”。我的 sql 查询的结果去哪了，为什么我检索不到？

【问题讨论】：

标签： .net sql-server vb.net ado.net

【解决方案1】：

这就是问题所在：

Console.WriteLine(reader.ToString)

您直接在阅读器上调用ToString，而不是要求它从当前行获取特定值。比如：

Console.WriteLine(reader.GetString(0))

应该没问题。

【讨论】：

我知道 .ToString 所做的正是它所假设的，我只是不知道还能使用什么。 .GetString 和 .GetValue 都运行良好。谢谢！

【解决方案2】：

Dim str As String

Dim myConn As SqlConnection = New SqlConnection("Server=(local)\netsdk;" & _
                                                "uid=sa;pwd=;database=master")

str = "CREATE DATABASE MyDatabase ON PRIMARY " & _
      "(NAME = MyDatabase_Data, " & _
      " FILENAME = 'D:\MyFolder\MyDatabaseData.mdf', " & _
      " SIZE = 2MB, " & _
      " MAXSIZE = 10MB, " & _
      " FILEGROWTH = 10%) " & _
      " LOG ON " & _
      "(NAME = MyDatabase_Log, " & _
      " FILENAME = 'D:\MyFolder\MyDatabaseLog.ldf', " & _
      " SIZE = 1MB, " & _
      " MAXSIZE = 5MB, " & _
      " FILEGROWTH = 10%) "

Dim myCommand As SqlCommand = New SqlCommand(str, myConn)

Try
    myConn.Open()
    myCommand.ExecuteNonQuery()
    MessageBox.Show("Database is created successfully", _
                    "MyProgram", MessageBoxButtons.OK, _
                     MessageBoxIcon.Information)
   Catch ex As Exception
       MessageBox.Show(ex.ToString())
   Finally
       If (myConn.State = ConnectionState.Open) Then
           myConn.Close()
       End If
   End Try

结束子

【讨论】：