database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-07 00:36:50 +03:00
Code Activity

Suggest shell here-documents instead of psql -c for multiple commands.

Browse Source 
The documentation suggested using "echo | psql", but not the often-superior
alternative of a here-document.  Also, be more direct about suggesting
that people avoid -c for multiple commands.  Per discussion.
This commit is contained in:
Tom Lane
2014-02-14 12:54:58 -05:00
parent 7644a7bd8c
commit b0154f20b3
1 changed files with 17 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
doc/src/sgml/ref/psql-ref.sgml
View File

@ -88,8 +88,8 @@ PostgreSQL documentation
or a single backslash command. Thus you cannot mix or a single backslash command. Thus you cannot mix
<acronym>SQL</acronym> and <application>psql</application> <acronym>SQL</acronym> and <application>psql</application>
meta-commands with this option. To achieve that, you could meta-commands with this option. To achieve that, you could
pipe the string into <application>psql</application>, like pipe the string into <application>psql</application>, for example:
this: <literal>echo '\x \\ SELECT * FROM foo;' | psql</literal>. <literal>echo '\x \\ SELECT * FROM foo;' | psql</literal>.
(<literal>\\</> is the separator meta-command.) (<literal>\\</> is the separator meta-command.)
</para> </para>
<para> <para>
@ -98,7 +98,21 @@ PostgreSQL documentation
<command>BEGIN</>/<command>COMMIT</> commands included in the <command>BEGIN</>/<command>COMMIT</> commands included in the
string to divide it into multiple transactions. This is string to divide it into multiple transactions. This is
different from the behavior when the same string is fed to different from the behavior when the same string is fed to
<application>psql</application>'s standard input. <application>psql</application>'s standard input. Also, only
the result of the last SQL command is returned.
</para>
<para>
Because of these legacy behaviors, putting more than one command in
the <option>-c</option> string often has unexpected results. It's
better to feed multiple commands to <application>psql</application>'s
standard input, either using <application>echo</application> as
illustrated above, or via a shell here-document, for example:
<programlisting>
psql &lt;&lt;EOF
\x
SELECT * FROM foo;
EOF
</programlisting>
</para> </para>
</listitem> </listitem>
</varlistentry> </varlistentry>