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Implement '\copy from -' to support reading copy data from the same

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source the \copy came from.  Also, fix prompting logic so that initial
and per-line prompts appear for all cases of reading from an interactive
terminal.  Patch by Mark Feit, with some kibitzing by Tom Lane.
This commit is contained in:
Tom Lane
2004-01-20 23:48:56 +00:00
parent 0f8a313508
commit 04cc4e18dd
4 changed files with 68 additions and 32 deletions
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40
doc/src/sgml/ref/psql-ref.sgml
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@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.103 2004/01/20 19:49:34 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.104 2004/01/20 23:48:56 tgl Exp $
PostgreSQL documentation
-->
@ -705,7 +705,7 @@ testdb=>
<term><literal>\copy <replaceable class="parameter">table</replaceable>
[ ( <replaceable class="parameter">column_list</replaceable> ) ]
{ <literal>from</literal> | <literal>to</literal> }
<replaceable class="parameter">filename</replaceable> | stdin | stdout
{ <replaceable class="parameter">filename</replaceable> | stdin | stdout | - }
[ <literal>with</literal> ]
[ <literal>oids</literal> ]
[ <literal>delimiter [as] </literal> '<replaceable class="parameter">character</replaceable>' ]
@ -720,26 +720,41 @@ testdb=>
reading or writing the specified file,
<application>psql</application> reads or writes the file and
routes the data between the server and the local file system.
This means that file accessibility and privileges are those
of the local user, not the server, and no SQL superuser
privileges are required.
This means that file accessibility and privileges are those of
the local user, not the server, and no SQL superuser
privileges are required.
</para>
<para>
The syntax of the command is similar to that of the
<acronym>SQL</acronym> <command>COPY</command> command. (See its
description for the details.) Note that, because of this,
<acronym>SQL</acronym> <xref linkend="sql-copy"
endterm="sql-copy-title"> command. Note that, because of this,
special parsing rules apply to the <command>\copy</command>
command. In particular, the variable substitution rules and
backslash escapes do not apply.
</para>
<para>
For <literal>\copy <replaceable
class="parameter">table</replaceable> from <replaceable
class="parameter">filename</replaceable></literal> operations,
<application>psql</application> adds the option of using a
hyphen instead of <replaceable
class="parameter">filename</replaceable>. This causes
<literal>\copy</literal> to read rows from the same source that
issued the command, continuing until <literal>\.</literal> is
read or the stream reaches <acronym>EOF</>. This option is
useful for populating tables in-line within a SQL script file.
In contrast, <literal>\copy from stdin</> always reads from
<application>psql</application>'s standard input.
</para>
<tip>
<para>
This operation is not as efficient as the <acronym>SQL</acronym>
<command>COPY</command> command because all data must pass
through the client/server connection. For large
amounts of data the other technique may be preferable.
amounts of data the <acronym>SQL</acronym> command may be preferable.
</para>
</tip>
@ -747,11 +762,12 @@ testdb=>
<para>
Note the difference in interpretation of
<literal>stdin</literal> and <literal>stdout</literal> between
client and server copies: in a client copy these always
<literal>\copy</literal> and <command>COPY</command>.
In <literal>\copy</literal> these always
refer to <application>psql</application>'s input and output
stream. On a server copy <literal>stdin</literal> comes from
wherever the <command>COPY</command> itself came from (for
example, a script run with the <option>-f</option> option), and
streams. In <command>COPY</command>, <literal>stdin</literal> comes
from wherever the <command>COPY</command> itself came from (for
example, a script run with the <option>-f</option> option), while
<literal>stdout</literal> refers to the query output stream (see
<command>\o</command> meta-command below).
</para>