Because pg_query() returns FALSE if the query fails, you must must use pg_send_query() and pg_get_result() to get the result handle.
PostgreSQL 7.4 introduced a new function called PQresultErrorField() that can be used to get SQLSTATE code from a query, which is far more useful than the error string returned from pg_result_error().
http://www.postgresql.org/docs/7.4/static/libpq-exec.html
http://www.postgresql.org/docs/7.4/static/errcodes-appendix.html
Here's a patch that adds the pg_result_error_field() function to PHP:
http://collapsed.net/patches/php-4.3.5RC3-pg_result_error_field.diff
(To apply the patch cd into your php-4.3.5RC directory and type: patch -p1 </path/to/php-4.3.5RC3-pg_result_error_field.diff)
Example code:
<?php
if(!($db = pg_connect("user=foo password=bar dbname=foobar")))
die("pg_connect");
if(!pg_send_query($db, "SELECT foo FROM bar"))
die("pg_send_query");
if(!($result = pg_get_result($db)))
die("pg_get_result");
echo(pg_result_error($result) . "<br />\n");
/* only available if you have patched php */
if(function_exists("pg_result_error_field"))
{
$fieldcode = array(
"PGSQL_DIAG_SEVERITY", "PGSQL_DIAG_SQLSTATE",
"PGSQL_DIAG_MESSAGE_PRIMARY", "PGSQL_DIAG_MESSAGE_DETAIL",
"PGSQL_DIAG_MESSAGE_HINT", "PGSQL_DIAG_STATEMENT_POSITION",
"PGSQL_DIAG_CONTEXT", "PGSQL_DIAG_SOURCE_FILE",
"PGSQL_DIAG_SOURCE_LINE", "PGSQL_DIAG_SOURCE_FUNCTION");
foreach($fieldcode as $fcode)
{
printf("%s: %s<br />\n",
$fcode,
pg_result_error_field($result, constant($fcode)));
}
pg_free_result($result);
}
?>
<?php pg_result_error_field($result, PGSQL_DIAG_SQLSTATE); ?>
Returns the SQLSTATE code.