pg_result_error()
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
获得查询结果的错误信息
说明
pg_result_error(resource $result): string
pg_result_error()返回和$result资源关联的错误信息。因此用户更有机会可以得到比pg_last_error()更好的错误信息。
参见pg_query(),pg_send_query(),pg_get_result(),pg_last_error()和pg_last_notice()。
pg_result_error does NOT work with prepared statements.
You can use pg_set_error_verbosity() to retrieve SQLSTATUS from pg_last_error().
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 $last_result; }
Because pg_query() returns FALSE if the query fails, you must must use pg_send_query() and pg_get_result() to get the result handle. PostgreSQL 7.4 introduced a new function called PQresultErrorField() that can be used to get SQLSTATE code from a query, which is far more useful than the error string returned from pg_result_error(). http://www.postgresql.org/docs/7.4/static/libpq-exec.html http://www.postgresql.org/docs/7.4/static/errcodes-appendix.html Here's a patch that adds the pg_result_error_field() function to PHP: http://collapsed.net/patches/php-4.3.5RC3-pg_result_error_field.diff (To apply the patch cd into your php-4.3.5RC directory and type: patch -p1 </path/to/php-4.3.5RC3-pg_result_error_field.diff) Example code: <?php if(!($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.