}

所以說，用.net新提供的managed provider來訪問oracle數據(system.data.oracleclient),
是無法以sys用戶登錄的。
這只有使用oracle odp.net（可以去oracle官方網站下載）

oracle odp.net數據庫訪問連接字符串 

connection string attribute 
默認值 
描述 
connection lifetime 
0 
maximum life time (in seconds) of the connection 
當數據庫連接被返回到連接池中時，它的創建時間將與當前時間比較，如果超過了 connection lifetime 規定的時間，它將被釋放掉。 為 0 時將被視為最大連接時間。 
connection timeout 
15 
maximum time (in seconds) to wait for a free connection from the pool 
data source 
empty string 
oracle net service name that identifies the database to connect to 
dba privilege 
empty string 
administrative privileges: sysdba or sysoper 
decr pool size 
1 
controls the number of connections that are closed when an excessive amount of established connections are unused 
enlist 
true 
enables or disables serviced components to automatically enlist in distributed transactions 
當此值為 true 時，池中現存的所有數據庫連接將被加入到它的創建線程的 transaction context 中。如果不存在這個 transaction context 則無任何變化。 
incr pool size 
5 
controls the number of connections that are established when all the connections in the pool are used 
max pool size 
100 
maximum number of connections in a  pool 
min pool size 
1 
minimum number of connections in a pool 
password 
empty string 
password for the user specified by user id 
persist security info 
false 
enables or disables the retrieval of password in the connection string 
pooling 
true 
enables or disables connection pooling 
proxy user id 
empty string 
user name of the proxy user 
proxy password 
empty string 
password of the proxy user 
user id 
empty string 
oracle user name 
  
  
  
// c# 
... 
oracleconnection con = new oracleconnection(); 
con.connectionstring = "user id=scott;password=tiger;data source=oracle;
pooling=true;enlist=true;min pool size=10;connection lifetime=120;
connection timeout=60;incr pool size=5; decr pool size=2"; 
con.open(); 
... 
  
以下網站提供連接字符串大全： 
www.connectionstrings.com