在 Ubuntu 18.04 服务器上安装 Oracle Express Edition 18c - 连接问题

Question

安装
数据库版本：Oracle 18c XE
在虚拟机管理器中运行的 Ubuntu 18.04 服务器上

问题
安装 Oracle XE 18c 后，我以用户 oracle 身份登录并启动监听器

lsnrctl start

当我尝试连接时出现以下问题：

A.使用：

sqlplus / as sysdba

=>

ERROR:
ORA-12547: TNS:lost contact

B.使用：

sqlplus oracle@ubu-srv as sysdba  

=>

ORA-12514: TNS:listener does not currently know of service requested in connect descriptor 

检查监听器：

lsnrctl status 

=>

LSNRCTL for Linux: Version 18.0.0.0.0 - Production on 28-MAR-2020 22:05:40  
Copyright (c) 1991, 2018, Oracle.  All rights reserved.  
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ubu-srv)(PORT=1521)))

STATUS of the LISTENER

Alias                     LISTENER  
Version                   TNSLSNR for Linux: Version 18.0.0.0.0 - Production  
Start Date                28-MAR-2020 21:28:33  
Uptime                    0 days 0 hr. 37 min. 6 sec  
Trace Level               off  
Security                  ON: Local OS Authentication  
SNMP                      OFF  
Default Service           XE  
Listener Parameter File   /opt/oracle/product/18c/dbhomeXE/network/admin/listener.ora  
Listener Log File         /opt/oracle/diag/tnslsnr/ubu-srv/listener/alert/log.xml  
Listening Endpoints Summary...  
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ubu-srv)(PORT=1521)))  
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))  
The listener supports no services  
The command completed successfully  

listener.ora 的内容：

  # listener.ora Network Configuration File: /opt/oracle/product/18c/dbhomeXE/network/admin/listener.ora  
  # Generated by Oracle configuration tools.  

DEFAULT_SERVICE_LISTENER = XE  

LISTENER =  
  (DESCRIPTION_LIST =  
    (DESCRIPTION =  
      (ADDRESS = (PROTOCOL = TCP)(HOST = ubu-srv)(PORT = 1521))  
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))  
    )  
  )  

tnsnames.ora 的内容：

  # tnsnames.ora Network Configuration File: /opt/oracle/product/18c/dbhomeXE/network/admin/tnsnames.ora  
  # Generated by Oracle configuration tools.  

LISTENER_XE =  
  (ADDRESS = (PROTOCOL = TCP)(HOST = ubu-srv)(PORT = 1521))  

Answer 1

数据库似乎没有在运行，或者它已经向网络侦听器注册。如果数据库正在运行，您应该会在运行“lsnrctl status”时看到列出的几个服务，如下所示：

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dbhost.example.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 18.0.0.0.0 - Production
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Default Service           XE
Listener Parameter File   /opt/oracle/product/18c/dbhomeXE/network/admin/listener.ora
Listener Log File         /opt/oracle/diag/tnslsnr/dbhost/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbhost.example.com)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=dbhost.example.com)(PORT=5500))(Security=(my_wallet_directory=/opt/oracle/admin/XE/xdb_wallet))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "77f81bd10c818208e053410cc40aef5a" has 1 instance(s).
  Instance "XE", status READY, has 1 handler(s) for this service...
Service "XE" has 1 instance(s).
  Instance "XE", status READY, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
  Instance "XE", status READY, has 1 handler(s) for this service...
Service "xepdb1" has 1 instance(s).
  Instance "XE", status READY, has 1 handler(s) for this service...
The command completed successfully

您根本不需要为您的选项 A 运行侦听器，从同一主机连接，但您需要设置 ORACLE_SID 环境变量以匹配您想要的数据库（容器或可插入数据库）的 SID连接到。要连接到容器数据库，如手动启动所有数据库服务，您可以这样做：

export ORACLE_SID=XE
sqlplus / as sysdba

对于选项 B，通过网络连接，您的连接字符串也会出现格式错误；除了主机名之外，它通常还应包括一个服务名称（最少）。有关示例，请参见此处：https://docs.oracle.com/en/database/oracle/oracle-database/18/sqpug/starting-SQL-Plus.html#GUID-A33231E7-9180-4544-A055-411209FD0363

sqlplus username@[//]host[:port][/service_name]
sqlplus pdb_admin@ubu-srv:1521/xepdb1

也就是说，Oracle 未通过 Ubuntu Linux 认证，因此无法保证结果。您应该在 CentOS、Red Hat 或 Oracle Linux 上运行它。支持的 Linux 版本的完整列表在这里：https://docs.oracle.com/en/database/oracle/oracle-database/18/ladbi/operating-system-checklist-for-oracle-database-installation-on-linux.html#GUID-E5C0A90E-7750-45D9-A8BC-C7319ED934F0