我认为数据源= xxxxxxx.db.yyyy.com：端口是问题。您应该提供文件 tnsnames.ora 中定义的TNS别名，而不是ServerName.Domain：Port。

我不知道OLEDB提供商是否支持Easy Connect命名方法。您在 sqlnet.ora 文件中指定像 NAMES.DIRECTORY_PATH =（tnsnames，ezconnect）

I'm using this connection string pattern with ADODB

Set oConn = New ADODB.Connection
oConn.ConnectionString = "User ID=USERNAME;Password=PW;Data Source=xxxxxxx.db.yyyy.com:port;Provider=OraOLEDB.Oracle; "
oConn.ConnectionTimeout = 30
oConn.Open
rs.CursorType = adOpenForwardOnly

and when I open the connection I'll get a run time error

ORA-12504: TNS:listener wa not given the SERVICE_NAME in CONNECT_DATA

I have also tried using this connection string

"ODBC;DRIVER={Oracle in OraClient11g_home2};" & _
"DBQ=" & inputHost & ";UID=" & inputUser & ";PWD=" & inputPassword & ";" & _
"HOST=" & inputHost & ";PORT=1521;DB=" & inputHost & ";" & _
"DefaultIsolationLevel=READUNCOMMITTED"

and I get the run time error

[Microsoft][ODBC Driver Manager] Data source name not found an no default driver specified

I think Data Source=xxxxxxx.db.yyyy.com:port is the problem. You should provide the TNS alias as defined in file tnsnames.ora instead of "ServerName.Domain:Port".

I do not know if OLEDB provider supports Easy Connect naming method. Did you specify like NAMES.DIRECTORY_PATH=(tnsnames, ezconnect) in your sqlnet.ora file?