pg_result_error

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

pg_result_error Get error message associated with result

Description

pg_result_error(PgSql\Result $result): string|false

pg_result_error() returns any error message associated with the result instance. Therefore, the user has a better chance of getting the correct error message than with pg_last_error().

The function pg_result_error_field() can give much greater detail on result errors than pg_result_error().

Because pg_query() returns false if the query fails, you must use pg_send_query() and pg_get_result() to get the result handle.

Parameters

result

An PgSql\Result instance, returned by pg_query(), pg_query_params() or pg_execute()(among others).

Return Values

Returns a string. Returns empty string if there is no error. If there is an error associated with the result parameter, returns false.

Changelog

Version Description
8.1.0 The result parameter expects an PgSql\Result instance now; previously, a resource was expected.

Examples

Example #1 pg_result_error() example

<?php
  $dbconn 
pg_connect("dbname=publisher") or die("Could not connect");

  if (!
pg_connection_busy($dbconn)) {
      
pg_send_query($dbconn"select * from doesnotexist;");
  }
  
  
$res1 pg_get_result($dbconn);
  echo 
pg_result_error($res1);
?>

See Also

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User Contributed Notes 4 notes

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6
spamuser at test dot com
10 years ago
pg_result_error does NOT work with prepared statements.
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0
VLroyrenn
2 years ago
So considering pg_query and pg_query_params don't return results on error, and that this would be an extremely handy thing to have, I just ended up writing my own functions wrapping the pg_send_* ones to work like the aforementionned two <em>should</em>. There's not a whole lot of code to them, the comments are mostly references from the libPQ and PHP doc, to explain the behavior.

<?php

class PostgresConnectionError extends Exception {
    public function
__construct($last_error) {
       
parent::__construct($message);
    }
}

function
pg_send_query_sync($connection, string $query) {
   
// This function cannot work if any query is already running for that connection because the results may then get mixed up.
   
assert(pg_get_result($connection) === false);

   
$dispatch_ok = pg_send_query($connection, $query);

   
// The *only* case where nothing can be returned, when the connection fails to dispatch the initial query.
   
if (!$dispatch_ok) throw new PostgresConnectionError(pg_​last_​error($connection));

   
// From the libPQ doc : "PQgetResult must be called repeatedly until it returns a null pointer, indicating that the command is done."

    // In the case of pg_query/PQExec, which we're trying to emulate:
    // "Note however that the returned PGresult structure describes only the result of the last command executed from the string."
    // "Should one of the commands fail, processing of the string stops with it and the returned PGresult describes the error condition."

   
while ($result = pg_get_result($connection)) {
       
// Drain all results on the connection and only return the last one.
       
if ($last_result) pg_free_result($last_result);
       
$last_result = $result;
    }

   
assert(is_resource($result) && get_resource_type($result) === "pgsql result");
    return
$last_result;
}

function
pg_send_query_params_sync($connection, string $query, array $params) {
   
// This function cannot work if any query is already running for that connection because the results may then get mixed up.
   
assert(pg_get_result($connection) === false);

   
$dispatch_ok = pg_send_query_params($connection, $query, $params);

   
// The *only* case where nothing can be returned, when the connection fails to dispatch the initial query.
   
if (!$dispatch_ok) throw new PostgresConnectionError(pg_​last_​error($connection));

   
// From the libPQ doc : "PQgetResult must be called repeatedly until it returns a null pointer, indicating that the command is done."
   
    // In the case of pg_query_params/PQExecParams, which we're trying to emulate:
    // "Unlike PQexec, PQexecParams allows at most one SQL command in the given string. (There can be semicolons in it, but not more than one nonempty command.)"

   
while ($result = pg_get_result($connection)) {
       
// Drain all results on the connection, although there should only be one.
       
if ($last_result) pg_free_result($last_result);
       
$last_result = $result;
    }

   
assert(is_resource($result) && get_resource_type($result) === "pgsql result");
    return
$last_result;
}
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0
axon dot wp at wp dot pl
15 years ago
You can  use pg_set_error_verbosity() to retrieve SQLSTATUS from pg_last_error().
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0
Anonymous
17 years ago
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.
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