16.3.6 ORA-12262

Indicates that the specified connection alias cannot be resolved due to invalid host name in the Easy Connect syntax.

Message

ORA-12262: Cannot connect to database.
Could not resolve hostname string 
    in Easy Connect connection string string.

For example:

ORA-12262: Cannot connect to database. 
Could not resolve hostname sales1.example.com
    in Easy Connect connection string sales1.example.com:1522/sales.

Cause

A connection to the database or other service is requested using a host name or Easy Connect connection string, but the host name is invalid and cannot be resolved.

Action

1. Check for mistakes in the specified connection string.

2. Ensure that the specified host name value is correct.

3. Try enclosing the connect identifier in quotation marks.