mysql_error
Данный модуль устарел, начиная с версии PHP 5.5.0, и удалён в PHP 7.0.0. Используйте вместо него MySQLi или PDO_MySQL. Смотрите также инструкцию MySQL: выбор API. Альтернативы для данной функции:
Описание
Возвращает текст ошибки выполнения последней функции MySQL. Ошибки работы с MySQL больше не вызывают сообщений в PHP. Вместо этого используйте функцию mysql_error() , для получения сообщения об ошибке. Учтите, что функция возвращает текст ошибки только последней выполненной функции MySQL (исключая mysql_error() и mysql_errno() ), поэтому убедитесь, что вы вызываете данную функцию до вызова следующей функции MySQL.
Список параметров
Соединение MySQL. Если идентификатор соединения не был указан, используется последнее соединение, открытое mysql_connect() . Если такое соединение не было найдено, функция попытается создать таковое, как если бы mysql_connect() была вызвана без параметров. Если соединение не было найдено и не смогло быть создано, генерируется ошибка уровня E_WARNING .
Возвращаемые значения
Возвращает текст ошибки выполнения последней функции MySQL, или » (пустую строку), если операция выполнена успешно.
Примеры
Пример #1 Пример использования mysql_error()
$link = mysql_connect ( «localhost» , «mysql_user» , «mysql_password» );
mysql_select_db ( «nonexistentdb» , $link );
echo mysql_errno ( $link ) . «: » . mysql_error ( $link ). «\n» ;
mysql_select_db ( «kossu» , $link );
mysql_query ( «SELECT * FROM nonexistenttable» , $link );
echo mysql_errno ( $link ) . «: » . mysql_error ( $link ) . «\n» ;
?>
Результатом выполнения данного примера будет что-то подобное:
1049: Unknown database 'nonexistentdb' 1146: Table 'kossu.nonexistenttable' doesn't exist
Смотрите также
User Contributed Notes 14 notes
If you want to display errors like «Access denied. «, when mysql_error() returns «» and mysql_errno() returns 0, use $php_errormsg. This Warning will be stored there. You need to have track_errors set to true in your php.ini.
Note. There is a bug in either documentation about error_reporting() or in mysql_error() function cause manual for mysql_error(), says: «Errors coming back from the MySQL database backend no longer issue warnings.» Which is not true.
Using a manipulation of josh ><>‘s function, I created the following. It’s purpose is to use the DB to store errors. It handles both original query, as well as the error log. Included Larry Ullman’s escape_data() as well since I use it in q().
function escape_data ( $data ) <
global $dbc ;
if( ini_get ( ‘magic_quotes_gpc’ )) <
$data = stripslashes ( $data );
>
return mysql_real_escape_string ( trim ( $data ), $dbc );
>
function q ( $page , $query ) <
// $page
$result = mysql_query ( $query );
if ( mysql_errno ()) <
$error = «MySQL error » . mysql_errno (). «: » . mysql_error (). «\n
When executing:
\n $query \n
» ;
$log = mysql_query ( «INSERT INTO db_errors (error_page,error_text) VALUES (‘ $page ‘,'» . escape_data ( $error ). «‘)» );
>
>
// Run the query using q()
$query = «INSERT INTO names (first, last) VALUES (‘myfirst’, ‘mylast'» );
$result = q ( «Sample Page Title» , $query );
?>
Be aware that if you are using multiple MySQL connections you MUST support the link identifier to the mysql_error() function. Otherwise your error message will be blank.
Just spent a good 30 minutes trying to figure out why i didn’t see my SQL errors.
When creating large applications it’s quite handy to create a custom function for handling queries. Just include this function in every script. And use db_query(in this example) instead of mysql_query.
This example prompts an error in debugmode (variable $b_debugmode ). An e-mail with the error will be sent to the site operator otherwise.
The script writes a log file in directory ( in this case /log ) as well.
The system is vulnerable when database/query information is prompted to visitors. So be sure to hide this information for visitors anytime.
$system_operator_mail = ‘developer@company.com’ ;
$system_from_mail = ‘info@mywebsite.com’ ;
function db_query ( $query ) global $b_debugmode ;
// Perform Query
$result = mysql_query ( $query );
// Check result
// This shows the actual query sent to MySQL, and the error. Useful for debugging.
if (! $result ) if( $b_debugmode ) $message = ‘Invalid query:
‘ . mysql_error () . ‘
‘ ;
$message .= ‘Whole query:
‘ . $query . ‘
‘ ;
die( $message );
>
raise_error ( ‘db_query_error: ‘ . $message );
>
return $result ;
>
function raise_error ( $message ) global $system_operator_mail , $system_from_mail ;
$serror =
«Env: » . $_SERVER [ ‘SERVER_NAME’ ] . «\r\n» .
«timestamp: » . Date ( ‘m/d/Y H:i:s’ ) . «\r\n» .
«script: » . $_SERVER [ ‘PHP_SELF’ ] . «\r\n» .
«error: » . $message . «\r\n\r\n» ;
// open a log file and write error
$fhandle = fopen ( ‘/logs/errors’ . date ( ‘Ymd’ ). ‘.txt’ , ‘a’ );
if( $fhandle ) fwrite ( $fhandle , $serror );
fclose (( $fhandle ));
>
// e-mail error to system operator
if(! $b_debugmode )
mail ( $system_operator_mail , ‘error: ‘ . $message , $serror , ‘From: ‘ . $system_from_mail );
>
some error can’t handle. Example:
ERROR 1044: Access denied for user: ‘ituser@mail.ramon.intranet’ to database ‘itcom’
This error ocurrs when a intent of a sql insert of no authorized user. The results: mysql_errno = 0 and the mysql_error = «» .
My suggested implementation of mysql_error():
$result = mysql_query($query) or die(«A fatal MySQL error occured.\n
Query: » . $query . «
\nError: (» . mysql_errno() . «) » . mysql_error());
This will print out something like.
A fatal MySQL error occured.
Query: SELECT * FROM table
Error: (err_no) Bla bla bla, you did everything wrong
It’s very useful to see your query in order to detect problems with syntax. Most often, the output message from MySQL doesn’t let you see enough of the query in the error message to let you see where your query went bad- it a missing quote, comma, or ( or ) could have occured well before the error was detected. I do -not- recomend using this procedure, however, for queries which execute on your site that are not user-specific as it has the potential to leak sensative data. Recomended use is just for debugging/building a script, and for general user-specific queries which would at the worst, leak the users own information to themself.
When dealing with user input, make sure that you use
echo htmlspecialchars ( mysql_error ());
?>
instead of
echo mysql_error ();
?>
Otherwise it might be possible to crack into your system by submitting data that causes the SQL query to fail and that also contains javascript commands.
Would it make sense to change the examples in the documentation for mysql_query () and for mysql_error () accordingly?
Oops, the code in my previous post only works for queries that don’t return data (INSERT, UPDATE, DELETE, etc.), this updated function should work for all types of queries (using $result = myquery($query);):
function myquery ($query) $result = mysql_query($query);
if (mysql_errno())
echo «MySQL error «.mysql_errno().»: «.mysql_error().»\n
When executing:
\n$query\n
«;
return $result;
>
A friend of mine proposed a great solution.
$old_track = ini_set ( ‘track_errors’ , ‘1’ );
if ( $this -> db_handle != FALSE && $db_selection_status != FALSE )
$this -> connected = 1 ;
ini_set ( ‘track_errors’ , $old_track );
>
else
$this -> connected =- 1 ;
$mysql_warning = $php_errormsg ;
ini_set ( ‘track_errors’ , $old_track );
throw new mysql_cns_exception ( 1 , $mysql_warning . » » . mysql_error ());
>
?>
My suggested implementation of mysql_error():
$result = mysql_query($query) or die(«A fatal MySQL error occured.\n
Query: » . $query . «
\nError: (» . mysql_errno() . «) » . mysql_error());
This will print out something like.
A fatal MySQL error occured.
Query: SELECT * FROM table
Error: (err_no) Bla bla bla, you did everything wrong
It’s very useful to see your query in order to detect problems with syntax. Most often, the output message from MySQL doesn’t let you see enough of the query in the error message to let you see where your query went bad- it a missing quote, comma, or ( or ) could have occured well before the error was detected. I do -not- recomend using this procedure, however, for queries which execute on your site that are not user-specific as it has the potential to leak sensative data. Recomended use is just for debugging/building a script, and for general user-specific queries which would at the worst, leak the users own information to themself.
«Errors coming back from the MySQL database backend no longer issue warnings.» Please note, you have an error/bug here. In fact, MySQL 5.1 with PHP 5.2:
Warning: mysql_connect() [function.mysql-connect]: Unknown MySQL server host ‘locallllllhost’ (11001)
That’s a warning, which is not trapped by mysql_error()!
This is a big one — As of MySQL 4.1 and above, apparently, the way passwords are hashed has changed. PHP 4.x is not compatible with this change, though PHP 5.0 is. I’m still using the 4.x series for various compatibility reasons, so when I set up MySQL 5.0.x on IIS 6.0 running PHP 4.4.4 I was surpised to get this error from mysql_error():
MYSQL: Client does not support authentication protocol requested by server; consider upgrading MySQL client
According to the MySQL site (http://dev.mysql.com/doc/refman/5.0/en/old-client.html) the best fix for this is to use the OLD_PASSWORD() function for your mysql DB user. You can reset it by issuing to MySQL:
Set PASSWORD for ‘user’@’host’ = OLD_PASSWORD(‘password’);
PHP MySQL query with error printing
How to write SQL using PHP to handle the data in MySQL database? In any database driven script we have to update, add, modify, data in the tables. By using PHP we can do all this using different functions available in PHP. We will start with very basic function, which will execute any query written in sql and can be applied to MySQL database.
SQL
Structured Query Language or popularly known as SQL is an universal language to handle database. An introduction and different types of sql command like select, insert, update etc you will get in the sql section of this site. There are some advance SQL commands like left join, linking of tables etc to study. If you are not comfortable with SQL any time you can refer the materials in sql section.
Connecting database and executing Query
To manage data we have to connect to MySQL database and execute query to get our date. Here there are two ways to use PHP drivers to connect to MySQL and execute the functions for getting records.
PHP Functions & SQL
Let us start with the function required to execute one query in PHP. Once you have connection established then we can execute sql command by using PHP function mysql_query(). Here is the syntax of the function.
Let us first write the query and store in a variable. We will write a query to create table.
$query="CREATE TABLE student ( id int(2) NOT NULL auto_increment, name varchar(50) NOT NULL default '', class varchar(10) NOT NULL default '', mark int(3) NOT NULL default '0', PRIMARY KEY (id) ) TYPE=MyISAM";We have stored the sql create query in a variable $query and we will pass this as a parameter to the function like below.
The above command will execute php_mysqli() the query ( stored in variable $query) and we can check the status of the query ( successful or not ) by checking the value of the variable $rt. $rt will be true if the query is successfully executed or it will return false. We will use php if command to check the status of the query.
So from the above line we can know that the query has worked or failed. But we will not come to know about the error if the database has some error and the query has failed. To get the error message we have to use another function mysqli_error() to print the error message returned by MySQL database after executing the query. Here it is how to print the error message.
The above line will print the error returned by mysql database if the query fails to execute. You can read more on mysql error here.
The complete code is available below.
$query="UPDATE student SET "; if ($connection->query($query)) < echo "Records Updated"; >else< echo $connection->error; >Before executing the above code we must connect to mysql database by using mysqli connection string.