为什么感觉自己语句上没啥问题，但是就是连不上数据库

Question

连不上数据库，“System.Data.OracleClient.OracleException”类型的未经处理的异常出现在 System.Data.OracleClient.dll 中。 其他信息: ORA-12154: TNS:could not resolve the connect identifier specified
代码如下，求解决啊：
Imports System.Data.OracleClient
Module CommModule
Public userlevel As String
Public flag As Integer
Public no As String
Public cno As String
Public mytable As DataTable
Public mysql As String
Public condstr As String = ""
Public mydv As New DataView()
Public logontime As Date
Public Function Exesql(ByVal mysql As String) As DataTable
Dim myconn As New OracleConnection
Dim mycmd As New OracleCommand
Dim mystr As String
mystr = "data source=orcl;user id=scott;password=tiger;"
myconn.ConnectionString = mystr
myconn.Open()
If Strings.InStr("INSERT,DELETE,UPDATE", Split(mysql, " ")(0).ToUpper) Then
mycmd.Connection = myconn
mycmd.CommandText = mysql
mycmd.CommandType = CommandType.Text
mycmd.ExecuteOracleNonQuery(mysql)
myconn.Close()
Return Nothing
Else
Dim myda As New OracleDataAdapter(mysql, myconn)
Dim myds As New DataSet
myda.Fill(myds)
myconn.Close()
Return myds.Tables(0)
End If
End Function
End Module

Answer 1

检查连接字符串，你这个错误提示是无法登录数据库，用户名密码问题，或者连接服务器失败。