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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2014-02-14 12:54:50 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2014-02-14 12:54:50 -0500 |
| commit | e7cf0b89fbf6a0c6e2fa7ece01197e9b6d6f48d3 (patch) | |
| tree | 148aa50e2253b59e6895f54c3d7b2c1c9b6a3b9f /doc/src | |
| parent | 7182bd239457b9cc3a1db337e3f10a9ee1388f78 (diff) | |
| download | postgresql-e7cf0b89fbf6a0c6e2fa7ece01197e9b6d6f48d3.tar.gz postgresql-e7cf0b89fbf6a0c6e2fa7ece01197e9b6d6f48d3.zip | |
Suggest shell here-documents instead of psql -c for multiple commands.
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.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/psql-ref.sgml | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index 4c65dc3e980..29631c0d7c7 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -83,14 +83,15 @@ PostgreSQL documentation (<filename>psqlrc</filename> and <filename>~/.psqlrc</filename>) are ignored with this option. </para> - <para><replaceable class="parameter">command</replaceable> must be either + <para> + <replaceable class="parameter">command</replaceable> must be either a command string that is completely parsable by the server (i.e., it contains no <application>psql</application>-specific features), or a single backslash command. Thus you cannot mix <acronym>SQL</acronym> and <application>psql</application> meta-commands with this option. To achieve that, you could - pipe the string into <application>psql</application>, like - this: <literal>echo '\x \\ SELECT * FROM foo;' | psql</literal>. + pipe the string into <application>psql</application>, for example: + <literal>echo '\x \\ SELECT * FROM foo;' | psql</literal>. (<literal>\\</> is the separator meta-command.) </para> <para> @@ -102,6 +103,19 @@ PostgreSQL documentation <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 <<EOF +\x +SELECT * FROM foo; +EOF +</programlisting> + </para> </listitem> </varlistentry> |