mysqli_stmt::fetch

mysqli_stmt_fetch

(PHP 5, PHP 7)

mysqli_stmt::fetch -- mysqli_stmt_fetch — Fetch results from a prepared statement into the bound variables

Description

Object oriented style

bool mysqli_stmt::fetch ( void )

Procedural style

bool mysqli_stmt_fetch ( mysqli_stmt $stmt )

Fetch the result from a prepared statement into the variables bound by mysqli_stmt_bind_result().

Note:
Note that all columns must be bound by the application before calling mysqli_stmt_fetch().

Note:
Data are transferred unbuffered without calling mysqli_stmt_store_result() which can decrease performance (but reduces memory cost).

Parameters

stmt: Procedural style only: A statement identifier returned by mysqli_stmt_init().

Return Values

**Return Values**
Value	Description
`TRUE`	Success. Data has been fetched
`FALSE`	Error occurred
`NULL`	No more rows/data exists or data truncation occurred

Examples

Example #1 Object oriented style


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

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$query = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 150,5";

if ($stmt = $mysqli->prepare($query)) {

    /* execute statement */
    $stmt->execute();

    /* bind result variables */
    $stmt->bind_result($name, $code);

    /* fetch values */
    while ($stmt->fetch()) {
        printf ("%s (%s)\n", $name, $code);
    }

    /* close statement */
    $stmt->close();
}

/* close connection */
$mysqli->close();
?>

Example #2 Procedural style


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

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$query = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 150,5";

if ($stmt = mysqli_prepare($link, $query)) {

    /* execute statement */
    mysqli_stmt_execute($stmt);

    /* bind result variables */
    mysqli_stmt_bind_result($stmt, $name, $code);

    /* fetch values */
    while (mysqli_stmt_fetch($stmt)) {
        printf ("%s (%s)\n", $name, $code);
    }

    /* close statement */
    mysqli_stmt_close($stmt);
}

/* close connection */
mysqli_close($link);
?>

The above examples will output:

Rockford (USA)
Tallahassee (USA)
Salinas (USA)
Santa Clarita (USA)
Springfield (USA)

User Contributed Notes

Bruce Martin

4 years ago


I was trying to use a generic select * from table statment and have the results returned in an array. I finally came up with this solution, others have similar solutions, but they where not working for me. 
<?php
    //Snip use normal methods to get to this point
    $stmt->execute();
    $metaResults = $stmt->result_metadata();
    $fields = $metaResults->fetch_fields();
    $statementParams='';
     //build the bind_results statement dynamically so I can get the results in an array
     foreach($fields as $field){
         if(empty($statementParams)){
             $statementParams.="\$column['".$field->name."']";
         }else{
             $statementParams.=", \$column['".$field->name."']";
         }
    }
    $statment="\$stmt->bind_result($statementParams);";
    eval($statment);
    while($stmt->fetch()){
        //Now the data is contained in the assoc array $column. Useful if you need to do a foreach, or 
        //if your lazy and didn't want to write out each param to bind.
    }
    // Continue on as usual.
?>

Lyndon

8 years ago


This function uses the same idea as the last, but instead binds the fields to a given array. 
<?php
function stmt_bind_assoc (&$stmt, &$out) {
    $data = mysqli_stmt_result_metadata($stmt);
    $fields = array();
    $out = array();

    $fields[0] = $stmt;
    $count = 1;

    while($field = mysqli_fetch_field($data)) {
        $fields[$count] = &$out[$field->name];
        $count++;
    }    
    call_user_func_array(mysqli_stmt_bind_result, $fields);
}

// example

$stmt = $mysqli->prepare("SELECT name, userid FROM somewhere");
$stmt->execute();

$row = array();
stmt_bind_assoc($stmt, $row);

// loop through all result rows
while ($stmt->fetch()) {
    print_r($row);
}
?>

dan dot latter at gmail dot com

8 years ago


The following function taken from PHP Cookbook 2, returns an associative array of a row in the resultset, place in while loop to iterate through whole result set.

<?php
public function fetchArray () {
   $data = mysqli_stmt_result_metadata($this->stmt);
        $fields = array();
        $out = array();

        $fields[0] = &$this->stmt;
        $count = 1;

        while($field = mysqli_fetch_field($data)) {
            $fields[$count] = &$out[$field->name];
            $count++;
        }
        
        call_user_func_array(mysqli_stmt_bind_result, $fields);
        mysqli_stmt_fetch($this->stmt);
        return (count($out) == 0) ? false : $out;

    }
?>

denath2 at yahoo dot com

7 years ago


As php at johnbaldock dot co dot uk mentioned the problem is that the $row returned is reference and not data. So, when you write  $array[] = $row, the $array will be filled up with the last element of the dataset. To come up with this you can write the following hack:

// loop through all result rows
while ($stmt->fetch()) {

    foreach( $row as $key=>$value )
    {
        $row_tmb[ $key ] = $value;
    } 
    $array[] = $row_tmb;
    
}

Brian

11 months ago


Same as everyone else, I was looking for a way NOT to have to duplicate the amount of code it takes to fetch the results of a prepared statement as an associative array.

Some of the other methods didn't work as written, and this one is packaged into a simple function to reduce code repetition.

Adapted from code others have posted.
<?php
// Example usage:
$id = 1;
$stmt = $dbc->prepare("SELECT * FROM table WHERE id=?");
if (!$stmt->bind_param('i', $id) || !$stmt->execute()) {
    throw new \Exception("Database error: $stmt->errno - $stmt->error");
}
$results = fetch_assoc_stmt($stmt);
$stmt->close();

/**
 * Fetches the results of a prepared statement as an array of associative
 * arrays such that each stored array is keyed by the result's column names.
 * @param stmt   Must have been successfully prepared and executed prior to calling this function
 * @param buffer Whether to buffer the result set; if true, results are freed at end of function
 * @return An array, possibly empty, containing one associative array per result row
 */
function fetch_assoc_stmt(\mysqli_stmt $stmt, $buffer = true) {
    if ($buffer) {
        $stmt->store_result();
    }
    $fields = $stmt->result_metadata()->fetch_fields();
    $args = array();
    foreach($fields AS $field) {
        $key = str_replace(' ', '_', $field->name); // space may be valid SQL, but not PHP
        $args[$key] = &$field->name; // this way the array key is also preserved
    }
    call_user_func_array(array($stmt, "bind_result"), $args);
    $results = array();
    while($stmt->fetch()) {
        $results[] = array_map("copy_value", $args);
    }
    if ($buffer) {
        $stmt->free_result();
    }
    return $results;
}

/**
 * Copy value as value
 */
function copy_value($v) {
    return $v;
}
?>

andrey at php dot net

11 years ago


IMPORTANT note: Be careful when you use this function with big result sets or with BLOB/TEXT columns. When one or more columns are of type (MEDIUM|LONG)(BLOB|TEXT) and ::store_result() was not called mysqli_stmt_fetch() will try to allocate at least 16MB for every such column. It _doesn't_ matter that the longest value in the result set is for example 30 bytes, 16MB will be allocated. Therefore it is not the best idea ot use binding of parameters whenever fetching big data. Why? Because once the data is in the mysql result set stored in memory and then second time in the PHP variable.

php at johnbaldock dot co dot uk

9 years ago


Having just learned about call_user_func_array I reworked my fetch_assoc example. Swapping the following code makes for a more elegant (and faster) solution.

Using:
<?php
while ($columnName = $meta->fetch_field()) {
    $columns[] = &$results[$columnName->name];
}        
call_user_func_array(array($stmt, 'bind_result'), $columns);
?>

Instead of this code from my example below:
<?php
$bindResult = '$stmt->bind_result(';
while ($columnName = $meta->fetch_field()) {
   $bindResult .= '$results["'.$columnName->name.'"],';
}
$bindResult = rtrim($bindResult, ',') . ');';
eval($bindResult);
?>

The full reworked fetch_assoc code for reference:
<?php
$mysqli = new mysqli($dbHost, $dbUsername, $dbPassword, $dbDatabase);
$stmt = $mysqli->prepare('select * from foobar');
$stmt->execute();
$stmt->store_result();
$meta = $stmt->result_metadata();

while ($column = $meta->fetch_field()) {
   $bindVarsArray[] = &$results[$column->name];
}        
call_user_func_array(array($stmt, 'bind_result'), $bindVarsArray);

$stmt->fetch();

echo var_dump($results);
// outputs:
// 
// array(3) {
//  ["id"]=>
//  &int(1)
//  ["foo"]=>
//  &string(11) "This is Foo"
//  ["bar"]=>
//  &string(11) "This is Bar"
// }
?>

piedone at pyrocenter dot hu

7 years ago


I tried the mentioned stmt_bind_assoc() function, but somehow, very strangely it doesn't allow the values to be written in an array! In the while loop, the row is fetched correctly, but if I write $array[] = $row;, the array will be filled up with the last element of the dataset... Unfortunately I couldn't find a solution.

Typer85 at gmail dot com

9 years ago


Just a side note,

I see many people are contributing in ways to help return result sets for prepared statements in ASSOSITAVE arrays the same as the mysqli_fetch_assos function might return from a normal query issued via mysqli_query.

This is done, in all the examples I have seen, by dynamically getting the field names in the prepared statement and binding them using 'variable' variables, which are variables that are created dynamically with the name of the field names.

Some thing though you should take into consideration is illegal variable names in PHP. Assume that you have a field name in your database table named 'My Field' , notice the space between 'My' and 'Field'.

To dynamically create this variable is illegal in PHP as variables can not have spaces in them. Furthermore, you won't be able to access the binded data as you can not reference a variable like so:

<?php

// Syntax Error.

echo $My Table;

?>

The only suitable solution I find now is to replace all spaces in a field name with an underscore so that you can use the binded variable like so:

<?php

// This Works.

echo $My_Table;

// Notice the space is now replaced with an underscore.

?>

All you simply have to do is before you dynamically bind the data, so a string search for any spaces in the table name, replace them with an underscore, THEN bind the variable.

That way you should not run into problems.

php at johnbaldock dot co dot uk

9 years ago


I wanted a simple way to get the equivalent of fetch_assoc when using a prepared statement. I came up with the following:

<?php
$mysqli = new mysqli($dbHost, $dbUsername, $dbPassword, $dbDatabase);
$stmt = $mysqli->prepare('select * from foobar');
$stmt->execute();
$stmt->store_result();
$meta = $stmt->result_metadata();

// the following creates a bind_result string with an argument for each column in the query
// e.g. $stmt->bind_result($results["id"], $results["foo"], $results["bar"]);
$bindResult = '$stmt->bind_result(';
while ($columnName = $meta->fetch_field()) {
    $bindResult .= '$results["'.$columnName->name.'"],';
}
$bindResult = rtrim($bindResult, ',') . ');';

// executes the bind_result string
eval($bindResult);
$stmt->fetch();

echo var_dump($results);
// outputs:
// 
// array(3) {
//   ["id"]=>
//   &int(1)
//   ["foo"]=>
//   &string(11) "This is Foo"
//   ["bar"]=>
//   &string(11) "This is Bar"
// }
?>

mysqli_stmt::fetch

mysqli_stmt_fetch

Description

Parameters

Return Values

Examples

See Also

User Contributed Notes