Problem Description ------------------- You have installed Personal Oracle 8.0.4 (PO8) and Designer 2.1.2. When you try to make a SQL*Plus v3.3 connection from SQL*Net V2 you get an ORA-03121 error. Problem Explanation ------------------- Personal Oracle8 is installed with a LISTENER.ORA file that has two address lines: one with the host name of the system (such as USER-PC USING PORT 1521), and the second with the host name set to the loopback address 127.0.0.1. This has caused the listener to fail. Starting SQL*Plus without the listener working caused the error: ORA-3121: no interface driver connected. Solution Description -------------------- Remove the Address entry from LISTENER.ORA that references the PC name. Modify the LISTENER.ORA file so that it has one address entry, which is the entry for the loopback address of 127.0.0.1. For example: LISTENER = (ADDRESS= (PROTOCOL= TCP) (Host= 127.0.0.1) (Port= 1521) ) Explanation ----------- The listener did not start, and the SQL*Plus v3.3 connection failed to contact a listener and returned the error. SQL*Net v2 cannot make a BEQ connection to an Oracle8 database. Another symptom of this problem is Developer failing to connect to a Personal Oracle8 database. BEQ fails and the database might hang or an Ora-12547 error, TNS:lost contact, is returned. Implementing the above solution solves the problem. Note: There are a number of other possibilities if the server is on the network or has a network interface. There could be another address entry with the IP address of the system or the Host name if there is a method of interpreting the host name.
Action: If the message occurred during use of a program provided by Oracle Corporation, contact customer support. If a user program caused the message, relink the program with current versions of the Oracle libraries. 你装的是8I，为什么会有7。3。3的SQLPLUS呢，是不是装有两个系统？