PostgreSQL database does not exist error I am getting a "database does not exist error", even when the database exists:

postgres=# GRANT ALL PRIVILEGES ON DATABASE Owino to OdooD;



  ERROR:  database "owino" does not exist


Name    |  Owner   | Encoding |   Collate   |    Ctype    |    Access privileges

Owino   | dominus  | UTF8     | en_US.UTF-8 | en_US.UTF-8 |
postgres| postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =Tc/postgres           +
        |          |          |             |             | postgres=CTc/postgres  +
        |          |          |             |             | orokon=CTc/postgres    +
        |          |          |             |             | powerbidev=CTc/postgres+
        |          |          |             |             | odoodev=CTc/postgres
The database was created with double quotes, so the name is now case-sensitive and you are now stuck with the dreaded quoted identifiers. "Owino" is a different name than Owino

GRANT ALL PRIVILEGES ON DATABASE "Owino" to OdooD;


Depending on how you created the user, you might need to use the dreaded double quotes for the user name as well ("OdooD"). 

I highly recommend to simply never use double quotes in SQL. 

See the manual for more details:
https://www.postgresql.org/docs/current/static/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS