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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
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+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>34.10. Functions Associated with the COPY Command</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="libpq-notify.html" title="34.9. Asynchronous Notification" /><link rel="next" href="libpq-control.html" title="34.11. Control Functions" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">34.10. Functions Associated with the <code xmlns="http://www.w3.org/1999/xhtml" class="command">COPY</code> Command</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="libpq-notify.html" title="34.9. Asynchronous Notification">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="libpq.html" title="Chapter 34. libpq — C Library">Up</a></td><th width="60%" align="center">Chapter 34. <span xmlns="http://www.w3.org/1999/xhtml" class="application">libpq</span> — C Library</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="libpq-control.html" title="34.11. Control Functions">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="LIBPQ-COPY"><div class="titlepage"><div><div><h2 class="title" style="clear: both">34.10. Functions Associated with the <code class="command">COPY</code> Command</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="libpq-copy.html#LIBPQ-COPY-SEND">34.10.1. Functions for Sending <code class="command">COPY</code> Data</a></span></dt><dt><span class="sect2"><a href="libpq-copy.html#LIBPQ-COPY-RECEIVE">34.10.2. Functions for Receiving <code class="command">COPY</code> Data</a></span></dt><dt><span class="sect2"><a href="libpq-copy.html#LIBPQ-COPY-DEPRECATED">34.10.3. Obsolete Functions for <code class="command">COPY</code></a></span></dt></dl></div><a id="id-1.7.3.17.2" class="indexterm"></a><p>
+ The <code class="command">COPY</code> command in
+ <span class="productname">PostgreSQL</span> has options to read from or write
+ to the network connection used by <span class="application">libpq</span>.
+ The functions described in this section allow applications to take
+ advantage of this capability by supplying or consuming copied data.
+ </p><p>
+ The overall process is that the application first issues the SQL
+ <code class="command">COPY</code> command via <a class="xref" href="libpq-exec.html#LIBPQ-PQEXEC"><code class="function">PQexec</code></a> or one
+ of the equivalent functions. The response to this (if there is no
+ error in the command) will be a <code class="structname">PGresult</code> object bearing
+ a status code of <code class="literal">PGRES_COPY_OUT</code> or
+ <code class="literal">PGRES_COPY_IN</code> (depending on the specified copy
+ direction). The application should then use the functions of this
+ section to receive or transmit data rows. When the data transfer is
+ complete, another <code class="structname">PGresult</code> object is returned to indicate
+ success or failure of the transfer. Its status will be
+ <code class="literal">PGRES_COMMAND_OK</code> for success or
+ <code class="literal">PGRES_FATAL_ERROR</code> if some problem was encountered.
+ At this point further SQL commands can be issued via
+ <a class="xref" href="libpq-exec.html#LIBPQ-PQEXEC"><code class="function">PQexec</code></a>. (It is not possible to execute other SQL
+ commands using the same connection while the <code class="command">COPY</code>
+ operation is in progress.)
+ </p><p>
+ If a <code class="command">COPY</code> command is issued via
+ <a class="xref" href="libpq-exec.html#LIBPQ-PQEXEC"><code class="function">PQexec</code></a> in a string that could contain additional
+ commands, the application must continue fetching results via
+ <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> after completing the <code class="command">COPY</code>
+ sequence. Only when <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> returns
+ <code class="symbol">NULL</code> is it certain that the <a class="xref" href="libpq-exec.html#LIBPQ-PQEXEC"><code class="function">PQexec</code></a>
+ command string is done and it is safe to issue more commands.
+ </p><p>
+ The functions of this section should be executed only after obtaining
+ a result status of <code class="literal">PGRES_COPY_OUT</code> or
+ <code class="literal">PGRES_COPY_IN</code> from <a class="xref" href="libpq-exec.html#LIBPQ-PQEXEC"><code class="function">PQexec</code></a> or
+ <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a>.
+ </p><p>
+ A <code class="structname">PGresult</code> object bearing one of these status values
+ carries some additional data about the <code class="command">COPY</code> operation
+ that is starting. This additional data is available using functions
+ that are also used in connection with query results:
+
+ </p><div class="variablelist"><dl class="variablelist"><dt id="LIBPQ-PQNFIELDS-1"><span class="term"><code class="function">PQnfields</code><a id="id-1.7.3.17.7.3.1.1.2" class="indexterm"></a></span></dt><dd><p>
+ Returns the number of columns (fields) to be copied.
+ </p></dd><dt id="LIBPQ-PQBINARYTUPLES-1"><span class="term"><code class="function">PQbinaryTuples</code><a id="id-1.7.3.17.7.3.2.1.2" class="indexterm"></a></span></dt><dd><p>
+ 0 indicates the overall copy format is textual (rows separated by
+ newlines, columns separated by separator characters, etc). 1
+ indicates the overall copy format is binary. See <a class="xref" href="sql-copy.html" title="COPY"><span class="refentrytitle">COPY</span></a> for more information.
+ </p></dd><dt id="LIBPQ-PQFFORMAT-1"><span class="term"><code class="function">PQfformat</code><a id="id-1.7.3.17.7.3.3.1.2" class="indexterm"></a></span></dt><dd><p>
+ Returns the format code (0 for text, 1 for binary) associated with
+ each column of the copy operation. The per-column format codes
+ will always be zero when the overall copy format is textual, but
+ the binary format can support both text and binary columns.
+ (However, as of the current implementation of <code class="command">COPY</code>,
+ only binary columns appear in a binary copy; so the per-column
+ formats always match the overall format at present.)
+ </p></dd></dl></div><p>
+ </p><div class="sect2" id="LIBPQ-COPY-SEND"><div class="titlepage"><div><div><h3 class="title">34.10.1. Functions for Sending <code class="command">COPY</code> Data</h3></div></div></div><p>
+ These functions are used to send data during <code class="literal">COPY FROM
+ STDIN</code>. They will fail if called when the connection is not in
+ <code class="literal">COPY_IN</code> state.
+ </p><div class="variablelist"><dl class="variablelist"><dt id="LIBPQ-PQPUTCOPYDATA"><span class="term"><code class="function">PQputCopyData</code><a id="id-1.7.3.17.8.3.1.1.2" class="indexterm"></a></span></dt><dd><p>
+ Sends data to the server during <code class="literal">COPY_IN</code> state.
+</p><pre class="synopsis">
+int PQputCopyData(PGconn *conn,
+ const char *buffer,
+ int nbytes);
+</pre><p>
+ </p><p>
+ Transmits the <code class="command">COPY</code> data in the specified
+ <em class="parameter"><code>buffer</code></em>, of length <em class="parameter"><code>nbytes</code></em>, to the server.
+ The result is 1 if the data was queued, zero if it was not queued
+ because of full buffers (this will only happen in nonblocking mode),
+ or -1 if an error occurred.
+ (Use <a class="xref" href="libpq-status.html#LIBPQ-PQERRORMESSAGE"><code class="function">PQerrorMessage</code></a> to retrieve details if
+ the return value is -1. If the value is zero, wait for write-ready
+ and try again.)
+ </p><p>
+ The application can divide the <code class="command">COPY</code> data stream
+ into buffer loads of any convenient size. Buffer-load boundaries
+ have no semantic significance when sending. The contents of the
+ data stream must match the data format expected by the
+ <code class="command">COPY</code> command; see <a class="xref" href="sql-copy.html" title="COPY"><span class="refentrytitle">COPY</span></a> for details.
+ </p></dd><dt id="LIBPQ-PQPUTCOPYEND"><span class="term"><code class="function">PQputCopyEnd</code><a id="id-1.7.3.17.8.3.2.1.2" class="indexterm"></a></span></dt><dd><p>
+ Sends end-of-data indication to the server during <code class="literal">COPY_IN</code> state.
+</p><pre class="synopsis">
+int PQputCopyEnd(PGconn *conn,
+ const char *errormsg);
+</pre><p>
+ </p><p>
+ Ends the <code class="literal">COPY_IN</code> operation successfully if
+ <em class="parameter"><code>errormsg</code></em> is <code class="symbol">NULL</code>. If
+ <em class="parameter"><code>errormsg</code></em> is not <code class="symbol">NULL</code> then the
+ <code class="command">COPY</code> is forced to fail, with the string pointed to by
+ <em class="parameter"><code>errormsg</code></em> used as the error message. (One should not
+ assume that this exact error message will come back from the server,
+ however, as the server might have already failed the
+ <code class="command">COPY</code> for its own reasons.)
+ </p><p>
+ The result is 1 if the termination message was sent; or in
+ nonblocking mode, this may only indicate that the termination
+ message was successfully queued. (In nonblocking mode, to be
+ certain that the data has been sent, you should next wait for
+ write-ready and call <a class="xref" href="libpq-async.html#LIBPQ-PQFLUSH"><code class="function">PQflush</code></a>, repeating until it
+ returns zero.) Zero indicates that the function could not queue
+ the termination message because of full buffers; this will only
+ happen in nonblocking mode. (In this case, wait for
+ write-ready and try the <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTCOPYEND"><code class="function">PQputCopyEnd</code></a> call
+ again.) If a hard error occurs, -1 is returned; you can use
+ <a class="xref" href="libpq-status.html#LIBPQ-PQERRORMESSAGE"><code class="function">PQerrorMessage</code></a> to retrieve details.
+ </p><p>
+ After successfully calling <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTCOPYEND"><code class="function">PQputCopyEnd</code></a>, call
+ <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> to obtain the final result status of the
+ <code class="command">COPY</code> command. One can wait for this result to be
+ available in the usual way. Then return to normal operation.
+ </p></dd></dl></div></div><div class="sect2" id="LIBPQ-COPY-RECEIVE"><div class="titlepage"><div><div><h3 class="title">34.10.2. Functions for Receiving <code class="command">COPY</code> Data</h3></div></div></div><p>
+ These functions are used to receive data during <code class="literal">COPY TO
+ STDOUT</code>. They will fail if called when the connection is not in
+ <code class="literal">COPY_OUT</code> state.
+ </p><div class="variablelist"><dl class="variablelist"><dt id="LIBPQ-PQGETCOPYDATA"><span class="term"><code class="function">PQgetCopyData</code><a id="id-1.7.3.17.9.3.1.1.2" class="indexterm"></a></span></dt><dd><p>
+ Receives data from the server during <code class="literal">COPY_OUT</code> state.
+</p><pre class="synopsis">
+int PQgetCopyData(PGconn *conn,
+ char **buffer,
+ int async);
+</pre><p>
+ </p><p>
+ Attempts to obtain another row of data from the server during a
+ <code class="command">COPY</code>. Data is always returned one data row at
+ a time; if only a partial row is available, it is not returned.
+ Successful return of a data row involves allocating a chunk of
+ memory to hold the data. The <em class="parameter"><code>buffer</code></em> parameter must
+ be non-<code class="symbol">NULL</code>. <em class="parameter"><code>*buffer</code></em> is set to
+ point to the allocated memory, or to <code class="symbol">NULL</code> in cases
+ where no buffer is returned. A non-<code class="symbol">NULL</code> result
+ buffer should be freed using <a class="xref" href="libpq-misc.html#LIBPQ-PQFREEMEM"><code class="function">PQfreemem</code></a> when no longer
+ needed.
+ </p><p>
+ When a row is successfully returned, the return value is the number
+ of data bytes in the row (this will always be greater than zero).
+ The returned string is always null-terminated, though this is
+ probably only useful for textual <code class="command">COPY</code>. A result
+ of zero indicates that the <code class="command">COPY</code> is still in
+ progress, but no row is yet available (this is only possible when
+ <em class="parameter"><code>async</code></em> is true). A result of -1 indicates that the
+ <code class="command">COPY</code> is done. A result of -2 indicates that an
+ error occurred (consult <a class="xref" href="libpq-status.html#LIBPQ-PQERRORMESSAGE"><code class="function">PQerrorMessage</code></a> for the reason).
+ </p><p>
+ When <em class="parameter"><code>async</code></em> is true (not zero),
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQGETCOPYDATA"><code class="function">PQgetCopyData</code></a> will not block waiting for input; it
+ will return zero if the <code class="command">COPY</code> is still in progress
+ but no complete row is available. (In this case wait for read-ready
+ and then call <a class="xref" href="libpq-async.html#LIBPQ-PQCONSUMEINPUT"><code class="function">PQconsumeInput</code>
+ </a> before calling
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQGETCOPYDATA"><code class="function">PQgetCopyData</code></a> again.) When <em class="parameter"><code>async</code></em> is
+ false (zero), <a class="xref" href="libpq-copy.html#LIBPQ-PQGETCOPYDATA"><code class="function">PQgetCopyData</code></a> will block until data is
+ available or the operation completes.
+ </p><p>
+ After <a class="xref" href="libpq-copy.html#LIBPQ-PQGETCOPYDATA"><code class="function">PQgetCopyData</code></a> returns -1, call
+ <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> to obtain the final result status of the
+ <code class="command">COPY</code> command. One can wait for this result to be
+ available in the usual way. Then return to normal operation.
+ </p></dd></dl></div></div><div class="sect2" id="LIBPQ-COPY-DEPRECATED"><div class="titlepage"><div><div><h3 class="title">34.10.3. Obsolete Functions for <code class="command">COPY</code></h3></div></div></div><p>
+ These functions represent older methods of handling <code class="command">COPY</code>.
+ Although they still work, they are deprecated due to poor error handling,
+ inconvenient methods of detecting end-of-data, and lack of support for binary
+ or nonblocking transfers.
+ </p><div class="variablelist"><dl class="variablelist"><dt id="LIBPQ-PQGETLINE"><span class="term"><code class="function">PQgetline</code><a id="id-1.7.3.17.10.3.1.1.2" class="indexterm"></a></span></dt><dd><p>
+ Reads a newline-terminated line of characters (transmitted
+ by the server) into a buffer string of size <em class="parameter"><code>length</code></em>.
+</p><pre class="synopsis">
+int PQgetline(PGconn *conn,
+ char *buffer,
+ int length);
+</pre><p>
+ </p><p>
+ This function copies up to <em class="parameter"><code>length</code></em>-1 characters into
+ the buffer and converts the terminating newline into a zero byte.
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINE"><code class="function">PQgetline</code></a> returns <code class="symbol">EOF</code> at the
+ end of input, 0 if the entire line has been read, and 1 if the
+ buffer is full but the terminating newline has not yet been read.
+ </p><p>
+ Note that the application must check to see if a new line consists
+ of the two characters <code class="literal">\.</code>, which indicates
+ that the server has finished sending the results of the
+ <code class="command">COPY</code> command. If the application might receive
+ lines that are more than <em class="parameter"><code>length</code></em>-1 characters long,
+ care is needed to be sure it recognizes the <code class="literal">\.</code>
+ line correctly (and does not, for example, mistake the end of a
+ long data line for a terminator line).
+ </p></dd><dt id="LIBPQ-PQGETLINEASYNC"><span class="term"><code class="function">PQgetlineAsync</code><a id="id-1.7.3.17.10.3.2.1.2" class="indexterm"></a></span></dt><dd><p>
+ Reads a row of <code class="command">COPY</code> data (transmitted by the
+ server) into a buffer without blocking.
+</p><pre class="synopsis">
+int PQgetlineAsync(PGconn *conn,
+ char *buffer,
+ int bufsize);
+</pre><p>
+ </p><p>
+ This function is similar to <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINE"><code class="function">PQgetline</code></a>, but it can be used
+ by applications
+ that must read <code class="command">COPY</code> data asynchronously, that is, without blocking.
+ Having issued the <code class="command">COPY</code> command and gotten a <code class="literal">PGRES_COPY_OUT</code>
+ response, the
+ application should call <a class="xref" href="libpq-async.html#LIBPQ-PQCONSUMEINPUT"><code class="function">PQconsumeInput</code>
+ </a> and
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINEASYNC"><code class="function">PQgetlineAsync</code></a> until the
+ end-of-data signal is detected.
+ </p><p>
+ Unlike <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINE"><code class="function">PQgetline</code></a>, this function takes
+ responsibility for detecting end-of-data.
+ </p><p>
+ On each call, <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINEASYNC"><code class="function">PQgetlineAsync</code></a> will return data if a
+ complete data row is available in <span class="application">libpq</span>'s input buffer.
+ Otherwise, no data is returned until the rest of the row arrives.
+ The function returns -1 if the end-of-copy-data marker has been recognized,
+ or 0 if no data is available, or a positive number giving the number of
+ bytes of data returned. If -1 is returned, the caller must next call
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQENDCOPY"><code class="function">PQendcopy</code></a>, and then return to normal processing.
+ </p><p>
+ The data returned will not extend beyond a data-row boundary. If possible
+ a whole row will be returned at one time. But if the buffer offered by
+ the caller is too small to hold a row sent by the server, then a partial
+ data row will be returned. With textual data this can be detected by testing
+ whether the last returned byte is <code class="literal">\n</code> or not. (In a binary
+ <code class="command">COPY</code>, actual parsing of the <code class="command">COPY</code> data format will be needed to make the
+ equivalent determination.)
+ The returned string is not null-terminated. (If you want to add a
+ terminating null, be sure to pass a <em class="parameter"><code>bufsize</code></em> one smaller
+ than the room actually available.)
+ </p></dd><dt id="LIBPQ-PQPUTLINE"><span class="term"><code class="function">PQputline</code><a id="id-1.7.3.17.10.3.3.1.2" class="indexterm"></a></span></dt><dd><p>
+ Sends a null-terminated string to the server. Returns 0 if
+ OK and <code class="symbol">EOF</code> if unable to send the string.
+</p><pre class="synopsis">
+int PQputline(PGconn *conn,
+ const char *string);
+</pre><p>
+ </p><p>
+ The <code class="command">COPY</code> data stream sent by a series of calls
+ to <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTLINE"><code class="function">PQputline</code></a> has the same format as that
+ returned by <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINEASYNC"><code class="function">PQgetlineAsync</code></a>, except that
+ applications are not obliged to send exactly one data row per
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTLINE"><code class="function">PQputline</code></a> call; it is okay to send a partial
+ line or multiple lines per call.
+ </p><div class="note"><h3 class="title">Note</h3><p>
+ Before <span class="productname">PostgreSQL</span> protocol 3.0, it was necessary
+ for the application to explicitly send the two characters
+ <code class="literal">\.</code> as a final line to indicate to the server that it had
+ finished sending <code class="command">COPY</code> data. While this still works, it is deprecated and the
+ special meaning of <code class="literal">\.</code> can be expected to be removed in a
+ future release. It is sufficient to call <a class="xref" href="libpq-copy.html#LIBPQ-PQENDCOPY"><code class="function">PQendcopy</code></a> after
+ having sent the actual data.
+ </p></div></dd><dt id="LIBPQ-PQPUTNBYTES"><span class="term"><code class="function">PQputnbytes</code><a id="id-1.7.3.17.10.3.4.1.2" class="indexterm"></a></span></dt><dd><p>
+ Sends a non-null-terminated string to the server. Returns
+ 0 if OK and <code class="symbol">EOF</code> if unable to send the string.
+</p><pre class="synopsis">
+int PQputnbytes(PGconn *conn,
+ const char *buffer,
+ int nbytes);
+</pre><p>
+ </p><p>
+ This is exactly like <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTLINE"><code class="function">PQputline</code></a>, except that the data
+ buffer need not be null-terminated since the number of bytes to send is
+ specified directly. Use this procedure when sending binary data.
+ </p></dd><dt id="LIBPQ-PQENDCOPY"><span class="term"><code class="function">PQendcopy</code><a id="id-1.7.3.17.10.3.5.1.2" class="indexterm"></a></span></dt><dd><p>
+ Synchronizes with the server.
+</p><pre class="synopsis">
+int PQendcopy(PGconn *conn);
+</pre><p>
+ This function waits until the server has finished the copying.
+ It should either be issued when the last string has been sent
+ to the server using <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTLINE"><code class="function">PQputline</code></a> or when the
+ last string has been received from the server using
+ <code class="function">PQgetline</code>. It must be issued or the server
+ will get <span class="quote">“<span class="quote">out of sync</span>”</span> with the client. Upon return
+ from this function, the server is ready to receive the next SQL
+ command. The return value is 0 on successful completion,
+ nonzero otherwise. (Use <a class="xref" href="libpq-status.html#LIBPQ-PQERRORMESSAGE"><code class="function">PQerrorMessage</code></a> to
+ retrieve details if the return value is nonzero.)
+ </p><p>
+ When using <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a>, the application should
+ respond to a <code class="literal">PGRES_COPY_OUT</code> result by executing
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQGETLINE"><code class="function">PQgetline</code></a> repeatedly, followed by
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQENDCOPY"><code class="function">PQendcopy</code></a> after the terminator line is seen.
+ It should then return to the <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> loop
+ until <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> returns a null pointer.
+ Similarly a <code class="literal">PGRES_COPY_IN</code> result is processed
+ by a series of <a class="xref" href="libpq-copy.html#LIBPQ-PQPUTLINE"><code class="function">PQputline</code></a> calls followed by
+ <a class="xref" href="libpq-copy.html#LIBPQ-PQENDCOPY"><code class="function">PQendcopy</code></a>, then return to the
+ <a class="xref" href="libpq-async.html#LIBPQ-PQGETRESULT"><code class="function">PQgetResult</code></a> loop. This arrangement will
+ ensure that a <code class="command">COPY</code> command embedded in a series
+ of <acronym class="acronym">SQL</acronym> commands will be executed correctly.
+ </p><p>
+ Older applications are likely to submit a <code class="command">COPY</code>
+ via <a class="xref" href="libpq-exec.html#LIBPQ-PQEXEC"><code class="function">PQexec</code></a> and assume that the transaction
+ is done after <a class="xref" href="libpq-copy.html#LIBPQ-PQENDCOPY"><code class="function">PQendcopy</code></a>. This will work
+ correctly only if the <code class="command">COPY</code> is the only
+ <acronym class="acronym">SQL</acronym> command in the command string.
+ </p></dd></dl></div></div></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="libpq-notify.html" title="34.9. Asynchronous Notification">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="libpq.html" title="Chapter 34. libpq — C Library">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="libpq-control.html" title="34.11. Control Functions">Next</a></td></tr><tr><td width="40%" align="left" valign="top">34.9. Asynchronous Notification </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 34.11. Control Functions</td></tr></table></div></body></html> \ No newline at end of file