Why I can't know if PostGIS is correctly installed on my PostgreSQL database?
<p>I am absolutly new in <strong>PostgreSQL</strong> and I am following this tutorial to check if I have <strong>PostGIS</strong> extension installed on my <strong>PostgreSQL</strong> installation.</p>

<p>This is the tutorial: <a href="https://www.a2hosting.com/kb/developer-corner/postgresql/determining-the-postgresql-and-postgis-versions" rel="nofollow">https://www.a2hosting.com/kb/developer-corner/postgresql/determining-the-postgresql-and-postgis-versions</a></p>

<p>I am using <strong>PostgreSQL 9.6.1</strong>.</p>

<p>So I have access to my <strong>PostgreSQL</strong> via the command line and I performed this command:</p>

<pre><code>SELECT PostGIS_full_version();
</code></pre>

<p>This is the obtained output:</p>

<p>C:\Users\Andrea>pasql -u admin
'pasql' is not recognized as an internal or external command,
operable program or batch file.</p>

<pre><code>C:\Users\Andrea&gt;psql -U postgres
psql (9.6.1)
ATTENZIONE: Il code page della console (850) differisce dal code page
            di Windows (1252). I caratteri a 8-bit potrebbero non
            funzionare correttamente. Vedi le pagine di riferimento
            psql "Note per utenti Windows" per i dettagli.
Digita "help" per avere un aiuto.

postgres=# SELECT PostGIS_full_version();
ERROR:  function postgis_full_version() does not exist
RIGA 1: SELECT PostGIS_full_version();
               ^
NOTA: No function matches the given name and argument types. You might need to add explicit type casts.
postgres=#
</code></pre>

<p>So I have done the access to the database with the standard user and then I have performed the command but seems that the <strong>PostGIS_full_version()</strong> function doesn't exist.</p>

<p>So what is means? It means that simply <strong>PoistGIS</strong> is not yet installed or am I doing something wrong? (maybe have I to perform it on a specific database?)</p>