An Oracle table or view does not exist ____oracle

1 Check Database connection information

2 Check the query's table name

3 View the permissions of the table and whether the currently logged on user has query permissions for the table.

4 ORACLE queries automatically convert uppercase so the query's table name plus "" is generated.

The problem was solved using the 4th.

In Java code

Select ID name from \ t_test\ where 1=1

In SQL view

Select ID name from "t_test" where 1=1

Failed to get connection

1 Check that the monitor and service are starting normally

2 Check whether the firewall is off (the port is blocked)

3 Modify the Listening parameters

Cmd

Lsnrctl

Lsnrctl > Status

Locate the listener's parameter file address

Modify listening files

Generally in the installation directory of the Oracle/product/dbhome_1/network/admin/listener.ora

In (address = (PROTOCOL=TCP) (HOST =localhost) (port=1521))

Append row

(address = (PROTOCOL=TCP) (HOST =xxx.xxx.xxx) (port=1521))

XXX is the IP address of the server.