ASP.NET数据库连接
您好,当我在服务器上运行应用程序时,连接未打开 -->我的数据集仍处于关闭状态ASP.NET数据库连接,asp.net,database,connection,Asp.net,Database,Connection,您好,当我在服务器上运行应用程序时,连接未打开 -->我的数据集仍处于关闭状态 Dim strconnect As String = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + "rootPath" + "\" + "VSS_TESTDB.mdb" + "Persist Security Info=False" Dim objConnection As New OleDbConnection(strconnect) Dim
Dim strconnect As String = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + "rootPath" + "\" + "VSS_TESTDB.mdb" + "Persist Security Info=False"
Dim objConnection As New OleDbConnection(strconnect)
Dim sql As String = "SELECT VSS_Files.id, VSS_Files.filename,VSS_Files.dateOfCreation,VSSDirs.dir FROM VSS_Files , VSSDirs Where VSS_Files.dir_id = VSSDirs.id;"
Dim cmd As New OleDbCommand(sql, objConnection)
Dim myDataReader As OleDbDataReader
myDataReader = cmd.ExecuteReader()
我能做什么
你好,泰扎克这个问题很模糊,很难从一行代码中正确诊断。以下是几点建议:
您需要使用OleDbConnectionStringBuilder创建OleDbConnection以连接到数据库 例如:
Dim builder As New OleDbConnectionStringBuilder
builder.Provider = "Microsoft.Jet.OLEDB.4.0"
builder.DataSource = Path.Combine(rootPath, "VSS_TESTDB.mdb")
builder.PersistSecurityInfo = False
Using connection As New OleDbConnection(builder.ToString())
Using command As New OleDbCommand("SELECT VSS_Files.id, VSS_Files.filename,VSS_Files.dateOfCreation,VSSDirs.dir FROM VSS_Files, VSSDirs Where VSS_Files.dir_id = VSSDirs.id;", connection)
connection.Open()
Using reader As OleDbDataReader = command.ExecuteReader()
'Do something
End Using
End Using
编辑:您的问题可能是在根路径
周围加了引号。连接字符串的数据源是DataSource=rootPath\VSS_TESTDB.mdb
。我假设您实际上希望它具有rootPath
变量的值
此外,您还需要打开连接
最后,应该使用using
语句关闭连接和数据读取器
查看我的更新示例。您好,很抱歉,我发布了更多代码:Dim strconnect As String=“Provider=Microsoft.Jet.OLEDB.4.0;”“+”数据源=“+”rootPath“+”\”+”VSS_TESTDB.mdb“+”Persist Security Info=False”Dim objConnection As New OleDbConnection(strconnect)Dim sql As String=“从VSS_文件中选择VSS_Files.id、VSS_Files.filename、VSS_Files.dateOfCreation、VSSDirs.dir,其中VSS_Files.dir_id=VSSDirs.id;“Dim cmd作为新的OleDbCommand(sql,objConnection)Dim myDataReader作为OleDbDataReader myDataReader=cmd.ExecuteReader()