How to open and close a pluggable database in 12c multitenant database

Connect to the container database:

sqlplus sys@cdbveg as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Wed Sep 6 13:22:57 2017

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Enter password:

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> show con_name

CON_NAME
------------------------------
CDB$ROOT
SQL>

Check status:

select con_id, dbid, name,open_mode from v$containers;

CON_ID	DBID	NAME	OPEN_MODE
1	3465911448	CDB$ROOT	READ WRITE
2	374976711	PDB$SEED	READ ONLY
3	53565692	PDBVEG1	MOUNTED

Open the pluggable database;

alter pluggable database pdbveg1 open;

Check status again:

CON_ID	DBID	NAME	OPEN_MODE
1	3465911448	CDB$ROOT	READ WRITE
2	374976711	PDB$SEED	READ ONLY
3	53565692	PDBVEG1	READ WRITE

To close the PDB and bring it back to a mounted state:

alter pluggable database pdbveg1 close;