PHP Australia Conference 2015

mysqli::query

mysqli_query

(PHP 5)

mysqli::query -- mysqli_query Выполняет запрос к базе данных

Описание

Объектно-ориентированный стиль

mixed mysqli::query ( string $query [, int $resultmode = MYSQLI_STORE_RESULT ] )

Процедурный стиль

mixed mysqli_query ( mysqli $link , string $query [, int $resultmode = MYSQLI_STORE_RESULT ] )

Выполняет запрос query к базе данных.

Функционально, использование этой функции идентично последовательному вызову функции mysqli_real_query(), а затем mysqli_use_result() или mysqli_store_result().

Замечание:

В случае, если длина выражения, которое вы передаете в mysqli_query(), больше, чем max_allowed_packet сервера, возвращаемые коды ошибки могут различаться в зависимости от используемого драйвера. А это может быть либо родной MySQL драйвер (mysqlnd), либо клиентская библиотека MySQL (libmysql). Поведение функции будет следующим:

  • mysqlnd на платформе Linux возвращает код ошибки 1153. Сообщение об ошибке означает "размер пакета превышает max_allowed_packet байт".

  • mysqlnd на платформе Windows возвращает код ошибки 2006. Это сообщение об ошибке означает "отказ сервера".

  • libmysql на всех платформах возвращает код ошибки 2006. Это сообщение об ошибке означает "отказ сервера".

Список параметров

link

Только для процедурного стиля: Идентификатор соединения, полученный с помощью mysqli_connect() или mysqli_init()

query

Текст запроса.

Данные в тексте запроса должны быть правильно экранированы.

resultmode

Либо константа MYSQLI_USE_RESULT, либо MYSQLI_STORE_RESULT в зависимости от требуемого поведения функции. По умолчанию используется MYSQLI_STORE_RESULT.

При использовании MYSQLI_USE_RESULT все последующие вызовы этой функции будут возвращать ошибку Commands out of sync до тех пор, пока не будет вызвана функция mysqli_free_result()

С константой MYSQLI_ASYNC (доступна при использовании mysqlnd) возможно выполнять запросы асинхронно. В этом случае для получения результатов каждого запроса необходимо использовать функцию mysqli_poll().

Возвращаемые значения

Возвращает FALSE в случае неудачи. В случае успешного выполнения запросов SELECT, SHOW, DESCRIBE или EXPLAIN mysqli_query() вернет объект mysqli_result. Для остальных успешных запросов mysqli_query() вернет TRUE.

Список изменений

Версия Описание
5.3.0 Добавлена возможность выполнять асинхронные запросы.

Примеры

Пример #1 Пример использования mysqli::query()

Объектно-ориентированный стиль

<?php
$mysqli 
= new mysqli("localhost""my_user""my_password""world");

/* проверка соединения */
if ($mysqli->connect_errno) {
    
printf("Не удалось подключиться: %s\n"$mysqli->connect_error);
    exit();
}

/* Создание таблицы не возвращает результирующего набора */
if ($mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    
printf("Таблица myCity успешно создана.\n");
}

/* Select запросы возвращают результирующий набор */
if ($result $mysqli->query("SELECT Name FROM City LIMIT 10")) {
    
printf("Select вернул %d строк.\n"$result->num_rows);

    
/* очищаем результирующий набор */
    
$result->close();
}

/* Если нужно извлечь большой объем данных, используем MYSQLI_USE_RESULT */
if ($result $mysqli->query("SELECT * FROM City"MYSQLI_USE_RESULT)) {

    
/* Важно заметить, что мы не можем вызывать функции, которые взаимодействуют
       с сервером, пока не закроем результирующий набор. Все подобные вызовы
       будут вызывать ошибку 'out of sync' */
    
if (!$mysqli->query("SET @a:='this will not work'")) {
        
printf("Ошибка: %s\n"$mysqli->error);
    }
    
$result->close();
}

$mysqli->close();
?>

Процедурный стиль

<?php
$link 
mysqli_connect("localhost""my_user""my_password""world");

/* проверка соединения */
if (mysqli_connect_errno()) {
    
printf("Не удалось подключиться: %s\n"mysqli_connect_error());
    exit();
}

/* Создание таблицы не возвращает результирующего набора */
if (mysqli_query($link"CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    
printf("Таблица myCity успешно создана.\n");
}

/* Select запросы возвращают результирующий набор */
if ($result mysqli_query($link"SELECT Name FROM City LIMIT 10")) {
    
printf("Select вернул %d строк.\n"mysqli_num_rows($result));

    
/* очищаем результирующий набор */
    
mysqli_free_result($result);
}

/* Если нужно извлечь большой объем данных, используем MYSQLI_USE_RESULT */
if ($result mysqli_query($link"SELECT * FROM City"MYSQLI_USE_RESULT)) {

    
/* Важно заметить, что мы не можем вызывать функции, которые взаимодействуют
       с сервером, пока не закроем результирующий набор. Все подобные вызовы
       будут вызывать ошибку 'out of sync' */
    
if (!mysqli_query($link"SET @a:='this will not work'")) {
        
printf("Ошибка: %s\n"mysqli_error($link));
    }
    
mysqli_free_result($result);
}

mysqli_close($link);
?>

Результат выполнения данных примеров:

Таблица myCity успешно создана.
Select вернул 10 строк.
Ошибка: Commands out of sync;  You can't run this command now

Смотрите также

add a note add a note

User Contributed Notes 18 notes

up
16
theyranos at gmail dot com
3 years ago
The cryptic "Couldn't fetch mysqli" error message can mean any number of things, including:

1. You're trying to use a database object that you've already closed (as noted by ceo at l-i-e dot com). Reopen your database connection, or find the call to <?php mysqli_close($db); ?> or <?php $db->close(); ?> and remove it.
2. Your MySQLi object has been serialized and unserialized for some reason. Define a wakeup function to re-create your database connection. http://php.net/__wakeup
3. Something besides you closed your mysqli connection (in particular, see http://bugs.php.net/bug.php?id=33772)
4. You mixed OOP and functional calls to the database object. (So, you have <?php $db->query() ?> in the same program as <?php mysqli_query($db) ?>).
up
9
NUNTIUS
6 years ago
This may or may not be obvious to people but perhaps it will help someone.

When running joins in SQL you may encounter a problem if you are trying to pull two columns with the same name. mysqli returns the last in the query when called by name. So to get what you need you can use an alias.

Below I am trying to join a user id with a user role. in the first table (tbl_usr), role is a number and in the second is a  text name (tbl_memrole is a lookup table). If I call them both as role I get the text as it is the last "role" in the query. If I use an alias then I get both as desired as shown below.

<?php
$sql
= "SELECT a.uid, a.role AS roleid, b.role,
            FROM tbl_usr a
            INNER JOIN tbl_memrole b
            ON a.role = b.id
            "
;

    if (
$result = $mysqli->query($sql)) {
        while(
$obj = $result->fetch_object()){
           
$line.=$obj->uid;
           
$line.=$obj->role;
           
$line.=$obj->roleid;
        }
    }
   
$result->close();
    unset(
$obj);
    unset(
$sql);
    unset(
$query);
   
?>
In this situation I guess I could have just renamed the role column in the first table roleid and that would have taken care of it, but it was a learning experience.
up
9
ceo at l-i-e dot com
6 years ago
Translation:
"Couldn't fetch mysqli"

You closed your connection and are trying to use it again.

It has taken me DAYS to figure out what this obscure error message means...
up
3
registrations at jdfoxmicro dot com
4 years ago
I like to save the query itself in a log file, so that I don't have to worry about whether the site is live.

For example, I might have a global function:

<?php
function UpdateLog ( $string , $logfile )  {
  
$fh = fopen ( $logfile , 'a' );
  
$fwrite ( $fh , strftime ('%F %T %z')." ".$string."\n";
  
fclose ( $fh );
}
?>

Then in my mysql function error trapper, something like this:

<?php
   $error_msg
= "Database error in [page].php / ";
  
$error_msg .= mysqli_error ( $link )." / ";
  
$error_msg .= $query;
  
UpdateLog ( $error_msg , DB_ERROR_LOG_FILE );
?>

I also include the remote IP, user agent, etc., but I left it out of these code samples.  And have it e-mail me when an error is caught, too.

Jeff
up
7
Igor
5 years ago
mysqli::query() can only execute one SQL statement.

Use mysqli::multi_query() when you want to run multiple SQL statements within one query.
up
7
petrus.jvr
3 years ago
When calling multiple stored procedures, you can run into the following error: "Commands out of sync; you can't run this command now".
This can happen even when using the close() function on the result object between calls.
To fix the problem, remember to call the next_result() function on the mysqli object after each stored procedure call. See example below:

<?php
// New Connection
$db = new mysqli('localhost','user','pass','database');

// Check for errors
if(mysqli_connect_errno()){
echo
mysqli_connect_error();
}

// 1st Query
$result = $db->query("call getUsers()");
if(
$result){
    
// Cycle through results
   
while ($row = $result->fetch_object()){
       
$user_arr[] = $row;
    }
   
// Free result set
   
$result->close();
   
$db->next_result();
}

// 2nd Query
$result = $db->query("call getGroups()");
if(
$result){
    
// Cycle through results
   
while ($row = $result->fetch_object()){
       
$group_arr[] = $row;
    }
    
// Free result set
    
$result->close();
    
$db->next_result();
}
else echo(
$db->error);

// Close connection
$db->close();
?>
up
3
jcwebb at dicoe dot com
7 years ago
When building apps, i like to see the whole statement when if fails.
<?php
$q
="SELECT somecolumn FROM sometable"; //some instruction
$r=mysqli_query($DBlink,$q) or die(mysqli_error($DBlink)." Q=".$q);
?>
If theres an error (like my numerous typing mistakes) this shows the entire instruction.
Good for development (not so good on production servers - simply find and replace when finished: $r=mysqli_query($DBlink,$q); )

Hope it helps. Jon
up
2
joseph_robert_martinez at yahoo dot com
6 months ago
For those using with replication enabled on their servers,  add a mysqli_select_db() statement before any data modification queries.  MySQL replication does not handle statements with db.table the same and will not replicate to the slaves if a scheme is not selected before.

Found out after days of resetting master and slaves on another site http://www.linuxquestions.org/questions/linux-server-73/mysql-5-1-not-replicating-properly-with-slave-823296/
up
1
Beeners
8 years ago
Stored Procedures.

Use mysqli_query to call a stored procedure that returns a result set.

Here is a short example:

<?php
$mysqli
= new mysqli(DBURI,DBUSER,DBPASS,DBNAME);
if (
mysqli_connect_errno())
{
 
printf("Connection failed: %s\n", mysqli_connect_error());
  exit();
}

$SQL = "CALL my_procedure($something)";
if ( (
$result = $mysqli->query($SQL))===false )
{
 
printf("Invalid query: %s\nWhole query: %s\n", $mysqli->error, $SQL);
  exit();
}

while (
$myrow = $result->fetch_array(MYSQLI_ASSOC))
{
 
$aValue[]=$myrow["a"];
 
$bValue[]=$myrow["b"];
}
$result->close();
$mysqli->close();
?>
I hope this saves someone some time.
up
1
ahmed dot 3abdolah at gmail dot com
18 days ago
Hi, i created function that add  a new table using array , i work with it on my projects ...
<?PHP
                  
/* this function was learned from PHP.net */
function array_keys_exist(&$key,array &$array){
               
$keys = split("\|",$key);
                foreach(
$keys as $key_s){
                    if(
array_key_exists($key_s, $array)) return true;
                    }
                return
false;
            }
/*and this is my function */
array_create_table(array &$array){
        if(
is_array($array)){
          
$key = "table|rows|values";   
       
$info = "";
        if(
array_keys_exist($key,$array)){
        if(
is_array($array["rows"]) and is_array($array["values"]) ){
                                        
            if(
count($array["rows"]) == count($array["values"])) {
                        for(
$i=0; $i<=count($array["rows"]); $i++){
   
$info = $info." ".$array["rows"][$i]." ".$array["values"][$i]." NOT NULL ";
            if(
$i < count($array["rows"])-1 ) $info = $info.",";
                    }
   
$query = "CREATE TABLE ".$this->private_tables_name.$array["table"]." ";
   
$query .= "( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, ".$info." )";
                    return
$query;   
                        }
                        }
                }else return
"Error";
                    }
            }

/* the use is simple */
$database = new database(); // connection to database i used mysqli ...
$array = array("table"=>"MRO", "rows"=>array("name","username") , "values" => array("VARCHAR (50) "," VARCHAR (50) ") );

$query = array_create_table($array); // convert and create the query ...
if($database->query($query)) echo "Work"; else echo "Error"; // result : work

?>
up
-3
marcus at synchromedia dot co dot uk
3 years ago
The exact type returned by a successful query is mysqli_result.
up
-5
thomas dekker
4 years ago
Building inserts can be annoying. This helper function inserts an array into a table, using the key names as column names:

<?php
 
private function store_array (&$data, $table, $mysqli)
  {
   
$cols = implode(',', array_keys($data));
    foreach (
array_values($data) as $value)
    {
      isset(
$vals) ? $vals .= ',' : $vals = '';
     
$vals .= '\''.$this->mysql->real_escape_string($value).'\'';
    }
   
$mysqli->real_query('INSERT INTO '.$table.' ('.$cols.') VALUES ('.$vals.')');
  }
?>

Adapt it to your specific needs.
up
-2
blinki bill, argodak at yahoo dot com
1 year ago
Recently I had puzzling problem when performing DML queries, update in particular, each time a update query is called and then there are some more queries to follow this error will show on the page and go in the error_log:
"Fatal error:  Exception thrown without a stack frame in Unknown on line 0"

The strange thing is that all queries go through just fine so it didn't make much sense:

$update = mysqli_query($connection, $query_string);
if(!$update){
echo 'Houston we have a problem '.mysqli_error($connection);
exit;
}

In the above example "$update" is "true", mysqli_error() is empty and of course the update operation goes through, however the nasty super cryptic error appears on the page.
What makes even less sense to me is how I fixed it - just called "mysqli_free_result" after the update query and the problem was gone, however because mysqli_free_result is not supposed to be called after DML queries (to free what, a boolean? lol) it needs to be wrapped in a try catch block:

try{
mysqli_free_result($update);
}catch (Exception $e){
//do nothing
}

So, I don't know why but it seems that when DML queries are responsible for:
"Fatal error:  Exception thrown without a stack frame in Unknown on line 0"
calling "mysqli_free_result" after the query seems to be fixing the issue
up
-3
antiriad at gmail dot com
7 years ago
this is a variant of mysqli_query that returns output parameters as a rowset.

<?php
 
function mysqli_exec($link, $command)
  {
     
$select = '';
     
$i2 = 0;
     
      while (
true)
      {
     
$i1 = strpos($command, '@', $i2);
     
      if (
$i1 === false)
          break;
         
     
$field = '';
     
$i2 = $i1 + 1;
     
      while (
$i2 < strlen($command) &&
          (
$command[$i2] >= '0' && $command[$i2] <= '9') ||
          (
$command[$i2] >= 'A' && $command[$i2] <= 'Z') ||
          (
$command[$i2] >= 'a' && $command[$i2] <= 'z') ||
          (
$command[$i2] == '_'))
         
$i2++;
         
     
$field = substr($command, $i1 + 1, $i2 - $i1 - 1);
         
      if (
strlen($select) == 0)
       
$select = "select @{$field} as $field";
      else                   
         
$select = $select . ", @{$field} as $field";
      }
     
      if (
strlen($select) > 0)
      {     
       
mysqli_query($link, $command);
        return
mysqli_query($link, $select);
      }
      else
        return
mysqli_query($link, $command);
  }
?>

an example:

<?php
  $link
= mysqli_connect('localhost', 'myusr', 'mypass') or die ('Error connecting to mysql: ' . mysqli_error($link));
 
mysqli_select_db($link, 'clips');
 
 
$user_name = 'test';
 
$result = mysqli_exec($link, "call do_user_login('$user_name', @session_id, @msg)");
 
  while (
$row = mysqli_fetch_assoc($result))
  {
    echo
"session_id : {$row['session_id']} <br>";
    echo
"msg        : {$row['msg']} <br>";
  }
?>
up
-2
andrey at php dot net
9 years ago
WARNING: This function was buggy on 64bit machines till 5.0.5. Affected versions 5.0.0-5.0.4. The problem appears when a value for the third parameter is passed - this will lead to instant FALSE returned by the function. Therefore if you need to use unbuffered query don't use this function with the aforementioned versions but you mysqli_real_query() and mysqli_use_result().
If you have the rights to patch you PHP installation the fix is easy:
In file ext/mysqli/myslqi_nonapi.c, function PHP_FUNCTION(mysqli_query)
change
unsigned int resultmode=0;
to
unsigned long resultmode=0;

Thanks!
up
-4
info at ff dot net
8 years ago
Calling Stored Procedures

Beeners' note/example will not work. Use mysqli_multi_query() to call a Stored Procedure. SP's have a second result-set which contains the status: 'OK' or 'ERR'. Using mysqli_query will not work, as there are multiple results.

<?php
$sQuery
="CALL SomeSP('params')";
if(!
mysqli_multi_query($sqlLink,$sQuery)) {
 
// your error handler
}
$sqlResult=mysqli_store_result($sqlLink);

if(
mysqli_more_results($this->sqlLink))//Catch 'OK'/'ERR'
 
while(mysqli_next_result($this->sqlLink));
?>

You will have to rewrite/expand this a bit for more usability of course, but it's just an example.
up
-4
hunreal at gmail dot com
10 years ago
Use difference collation/character for connect, result.
You can set the collation before your query.

E.g. want to set the collation to utf8_general_ci
you can send the query "SET NAMES 'utf8'" first

<?php
$mysqli
=new mysqli('localhost', 'root', 'password', 'test');
$mysqli->query("SET NAMES 'utf8'");
$q=$mysqli->query("select * from test");
while(
$r=$q->fetch_assoc()) {
   
print_r($r);
}
?>

There are many variables about character settings.
By running sql command, SHOW VARIABLES LIKE 'char%';
There are some variables control the character usage.

character_set_client
character_set_connection
character_set_database
character_set_results
character_set_server
character_set_system

Also SET NAMES can repalce with one or some settings like SET character_set_results='utf8';
up
-8
popere dot noel at yahoo dot com
1 year ago
or you could just extend the class...
in my case i already had a wraper for the db so something like this was easy :

public function  free($result) {
 
  $result->free_result();
$this->link->next_result();
}

just tried it and it works like a charm ;-)
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