postgresql/doc/src/sgml/ref/dropdb.sgml
Robert Haas 68281e0054 Make command-line tools smarter about finding a DB to connect to.
If unable to connect to "postgres", try "template1".  This allows things to
work more smoothly in the case where the postgres database has been
dropped.  And just in case that's not good enough, also allow the user to
specify a maintenance database to be used for the initial connection, to
cover the case where neither postgres nor template1 is suitable.
2011-12-06 08:48:15 -05:00

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<!--
doc/src/sgml/ref/dropdb.sgml
PostgreSQL documentation
-->
<refentry id="APP-DROPDB">
<refmeta>
<refentrytitle><application>dropdb</application></refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo>Application</refmiscinfo>
</refmeta>
<refnamediv>
<refname>dropdb</refname>
<refpurpose>remove a <productname>PostgreSQL</productname> database</refpurpose>
</refnamediv>
<indexterm zone="app-dropdb">
<primary>dropdb</primary>
</indexterm>
<refsynopsisdiv>
<cmdsynopsis>
<command>dropdb</command>
<arg rep="repeat"><replaceable>connection-option</replaceable></arg>
<arg rep="repeat"><replaceable>option</replaceable></arg>
<arg choice="plain"><replaceable>dbname</replaceable></arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<application>dropdb</application> destroys an existing
<productname>PostgreSQL</productname> database.
The user who executes this command must be a database
superuser or the owner of the database.
</para>
<para>
<application>dropdb</application> is a wrapper around the
<acronym>SQL</acronym> command <xref linkend="SQL-DROPDATABASE">.
There is no effective difference between dropping databases via
this utility and via other methods for accessing the server.
</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>
<application>dropdb</> accepts the following command-line arguments:
<variablelist>
<varlistentry>
<term><replaceable class="parameter">dbname</replaceable></term>
<listitem>
<para>
Specifies the name of the database to be removed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-e</></term>
<term><option>--echo</></term>
<listitem>
<para>
Echo the commands that <application>dropdb</application> generates
and sends to the server.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-i</></term>
<term><option>--interactive</></term>
<listitem>
<para>
Issues a verification prompt before doing anything destructive.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>--if-exists</></term>
<listitem>
<para>
Do not throw an error if the database does not exist. A notice is issued
in this case.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-V</></term>
<term><option>--version</></term>
<listitem>
<para>
Print the <application>dropdb</application> version and exit.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-?</></term>
<term><option>--help</></term>
<listitem>
<para>
Show help about <application>dropdb</application> command line
arguments, and exit.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
<application>dropdb</application> also accepts the following
command-line arguments for connection parameters:
<variablelist>
<varlistentry>
<term><option>-h <replaceable class="parameter">host</replaceable></></term>
<term><option>--host=<replaceable class="parameter">host</replaceable></></term>
<listitem>
<para>
Specifies the host name of the machine on which the
server
is running. If the value begins with a slash, it is used
as the directory for the Unix domain socket.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-p <replaceable class="parameter">port</replaceable></></term>
<term><option>--port=<replaceable class="parameter">port</replaceable></></term>
<listitem>
<para>
Specifies the TCP port or local Unix domain socket file
extension on which the server
is listening for connections.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-U <replaceable class="parameter">username</replaceable></></term>
<term><option>--username=<replaceable class="parameter">username</replaceable></></term>
<listitem>
<para>
User name to connect as.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-w</></term>
<term><option>--no-password</></term>
<listitem>
<para>
Never issue a password prompt. If the server requires
password authentication and a password is not available by
other means such as a <filename>.pgpass</filename> file, the
connection attempt will fail. This option can be useful in
batch jobs and scripts where no user is present to enter a
password.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-W</></term>
<term><option>--password</></term>
<listitem>
<para>
Force <application>dropdb</application> to prompt for a
password before connecting to a database.
</para>
<para>
This option is never essential, since
<application>dropdb</application> will automatically prompt
for a password if the server demands password authentication.
However, <application>dropdb</application> will waste a
connection attempt finding out that the server wants a password.
In some cases it is worth typing <option>-W</> to avoid the extra
connection attempt.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>--maintenance-db=<replaceable class="parameter">dbname</replaceable></></term>
<listitem>
<para>
Specifies the name of the database to connect to in order to drop the
target database. If not specified, the <literal>postgres</literal>
database will be used; if that does not exist (or is the database
being dropped), <literal>template1</literal> will be used.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1>
<title>Environment</title>
<variablelist>
<varlistentry>
<term><envar>PGHOST</envar></term>
<term><envar>PGPORT</envar></term>
<term><envar>PGUSER</envar></term>
<listitem>
<para>
Default connection parameters
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
This utility, like most other <productname>PostgreSQL</> utilities,
also uses the environment variables supported by <application>libpq</>
(see <xref linkend="libpq-envars">).
</para>
</refsect1>
<refsect1>
<title>Diagnostics</title>
<para>
In case of difficulty, see <xref linkend="SQL-DROPDATABASE">
and <xref linkend="APP-PSQL"> for
discussions of potential problems and error messages.
The database server must be running at the
targeted host. Also, any default connection settings and environment
variables used by the <application>libpq</application> front-end
library will apply.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
To destroy the database <literal>demo</literal> on the default
database server:
<screen>
<prompt>$ </prompt><userinput>dropdb demo</userinput>
</screen>
</para>
<para>
To destroy the database <literal>demo</literal> using the
server on host <literal>eden</literal>, port 5000, with verification and a peek
at the underlying command:
<screen>
<prompt>$ </prompt><userinput>dropdb -p 5000 -h eden -i -e demo</userinput>
<computeroutput>Database "demo" will be permanently deleted.
Are you sure? (y/n) </computeroutput><userinput>y</userinput>
<computeroutput>DROP DATABASE demo;</computeroutput>
</screen></para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="app-createdb"></member>
<member><xref linkend="sql-dropdatabase"></member>
</simplelist>
</refsect1>
</refentry>