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PHP mysqli: use_result() function

mysqli_use_result function / mysqli::use_result

The mysqli_use_result function / mysqli::use_result — initiate a result set retrieval.

Syntax:

Object oriented style

mysqli_result mysqli::use_result ( void )

Procedural style

mysqli_result mysqli_use_result ( mysqli $link )

Parameter:

Name Description Required/Optional
link A link identifier returned by mysqli_connect() or mysqli_init() Required for procedural style only and Optional for Object oriented style

Usage: Procedural style

mysqli_use_result(connection);

Parameter:

Name Description Required/Optional
connection Specifies the MySQL connection to use. Required

Return value:

Returns an unbuffered result object or FALSE if an error occurred.

Version: PHP 5, PHP 7

Example of object oriented style:

<?php
$mysqli = new mysqli("localhost", "my_user", "datasoft123", "hr");

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

$query  = "SELECT CURRENT_USER();";
$query .= "SELECT Name FROM City ORDER BY ID LIMIT 20, 5";

/* execute multi query */
if ($mysqli->multi_query($query)) {
    do {
        /* store first result set */
        if ($result = $mysqli->use_result()) {
            while ($row = $result->fetch_row()) {
                printf("%s\n", $row[0]);
            }
            $result->close();
        }
        /* print divider */
        if ($mysqli->more_results()) {
            printf("-----------------\n");
        }
    } while ($mysqli->next_result());
}

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

Output:

[email protected]% -----------------

Example of the Procedural style

<?php
$link = mysqli_connect("localhost", "user", "datasoft123", "hr");

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

$query  = "SELECT CURRENT_USER();";
$query .= "SELECT Name FROM city ORDER BY ID LIMIT 20, 5";

/* execute multi query */
if (mysqli_multi_query($link, $query)) {
    do {
        /* store first result set */
        if ($result = mysqli_use_result($link)) {
            while ($row = mysqli_fetch_row($result)) {
                printf("%s\n", $row[0]);
            }
            mysqli_free_result($result);
        }
        /* print divider */
        if (mysqli_more_results($link)) {
            printf("-----------------\n");
        }
    } while (mysqli_next_result($link));
}

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

Output:

Connect failed: Access denied for user 'user'@'localhost' (using password: YES)

Example:

<?php
$con=mysqli_connect("localhost","user1","datasoft123","hr");

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

$sql  = "SELECT CURRENT_USER();";
$sql .= "SELECT Name FROM City ORDER BY ID LIMIT 20, 5";

/* run a multi with */
if ($con->multi_query($sql)) {
    do {
        /* first store the result set */
        if ($resultado = $con->use_result()) {
            while ($fila = $resultado->fetch_row()) {
                printf("%s\n", $fila[0]);
            }
            $resultado->close();
        }
        /* print a separator */
        if ($con->more_results()) {
            printf("-----------------\n");
        }
    } while ($con->next_result());
}

// close connections
$con->close();
?>

Sample Output:

[email protected]% -----------------

See also

PHP Function Reference

Previous: thread_safe
Next: warning_count



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PHP: Tips of the Day

Getting all defined constants

To get all defined constants including those created by PHP use the get_defined_constants function:

Example:

<?php
$constants = get_defined_constants();
var_dump($constants); // pretty large list

Output:

array(2250) {
  ["E_ERROR"]=>
  int(1)
  ["E_RECOVERABLE_ERROR"]=>
  int(4096)
  ["E_WARNING"]=>
  .....
  .....
  resource(1) of type (stream)
  ["STDOUT"]=>
  resource(2) of type (stream)
  ["STDERR"]=>
  resource(3) of type (stream)
}

To get only those constants that were defined by your app call the function at the beginning and at the end of your script (normally after the bootstrap process):

<?php
$constants = get_defined_constants();
define("HELLO", "hello");
define("WORLD", "world");
$new_constants = get_defined_constants();
$myconstants = array_diff_assoc($new_constants, $constants);
var_export($myconstants);

Output:

array (
  'HELLO' => 'hello',
  'WORLD' => 'world',
)

It's sometimes useful for debugging

 





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