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    pg_result_error

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

    pg_result_error — Get error message associated with result

    Descrierea

    pg_result_error ( resource $result ) : string

    pg_result_error() returns any error message associated with the result resource. 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.

    Parametri

    result

    PostgreSQL query result resource, returned by pg_query(), pg_query_params() or pg_execute() (among others).

    Valorile întoarse

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

    Exemple

    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);
    ?>

    A se vedea și

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    User Contributed Notes 4 notes

    up
    6
    spamuser at test dot com
    13 years ago
    pg_result_error does NOT work with prepared statements.
    up
    0
    VLroyrenn
    5 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;
    }
    up
    0
    axon dot wp at wp dot pl
    18 years ago
    You can  use pg_set_error_verbosity() to retrieve SQLSTATUS from pg_last_error().
    up
    0
    Anonymous
    20 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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