====== Change character set (and national character set) for a database ======

**sqlplus /nolog**
<code>
SQL*Plus: Release 18.0.0.0.0 - Production on Sun Mar 24 23:38:27 2019
Version 18.3.0.0.0

Copyright (c) 1982, 2018, Oracle.  All rights reserved.
</code>
SQL> **connect SYS@PMJWE8 as SYSDBA;**
<code>
Enter password:
Connected.
</code>
SQL> **shutdown immediate;**
<code>
Pluggable Database closed.
</code>
SQL> **startup restrict;**
<code>
Pluggable Database opened.
</code>
SQL> **alter database character set internal_use WE8ISO8859P15;**
<code>
Database altered.
</code>
SQL> **alter database national character set internal_use AL16UTF16;**
<code>
Database altered.
</code>
SQL>** alter system disable restricted session;**
<code>
System altered.
</code>
SQL> **select * from nls_database_parameters where parameter like '%SET%';**
<code>
PARAMETER                 VALUE
------------------------- -------------------------
NLS_NCHAR_CHARACTERSET    AL16UTF16
NLS_CHARACTERSET          WE8ISO8859P15
</code>