mysqli_result::$num_rows

mysqli_num_rows

(PHP 5, PHP 7)

mysqli_result::$num_rows -- mysqli_num_rows — Gets the number of rows in a result

说明

面向对象风格

int $mysqli_result->num_rows;

过程化风格

int mysqli_num_rows ( mysqli_result $result )

Returns the number of rows in the result set.

The behaviour of mysqli_num_rows() depends on whether buffered or unbuffered result sets are being used. For unbuffered result sets, mysqli_num_rows() will not return the correct number of rows until all the rows in the result have been retrieved.

参数

result

仅以过程化样式：由 mysqli_query()，mysqli_store_result() 或 mysqli_use_result()返回的结果集标识。

返回值

Returns number of rows in the result set.

Note:

If the number of rows is greater than PHP_INT_MAX, the number will be returned as a string.

范例

Example #1 面向对象风格

<?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();
}

if ($result = $mysqli->query("SELECT Code, Name FROM Country ORDER BY Name")) {

    /* determine number of rows result set */
    $row_cnt = $result->num_rows;

    printf("Result set has %d rows.\n", $row_cnt);

    /* close result set */
    $result->close();
}

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

Example #2 过程化风格

<?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();
}

if ($result = mysqli_query($link, "SELECT Code, Name FROM Country ORDER BY Name")) {

    /* determine number of rows result set */
    $row_cnt = mysqli_num_rows($result);

    printf("Result set has %d rows.\n", $row_cnt);

    /* close result set */
    mysqli_free_result($result);
}

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

以上例程会输出：

Result set has 239 rows.

参见

User Contributed Notes

Amos &#39;D Great 09-Sep-2017 06:11
// Create Database Connection ..

$conn = new mysqli("localhost", "root", "", "my_db");
// run a query on a table from your DB.

$sql_rec = $conn->query("select count(msisdn) from my_colum where id = '$id'");  //  Take out the Where Clause if not Needed.
           if($sql_rec == true)
       {
          echo " The Total Number of MSISDNs are " . $sql_rec->num_rows;  
       }
         else
       {
          echo "Something Bad has happened, We have informed the village Elders.". $conn->connect_error();
       }
$conn->close();
Anonymous 14-Aug-2017 06:18
The method signature should be:

mixed mysqli_num_rows (mysqli_result $result)

"If the number of rows is greater than PHP_INT_MAX, the number will be returned as a string."
min0u 13-May-2017 11:56
This function doesn't work with LIMIT used jointly with SQL_CALC_FOUND_ROWS. If you want to obtain the total rows found you must do it manually, example:

<?php
public function errorList(int $limit=25,int $offset=0){
        $errorList = array();
        $result = $this->con->query("SELECT SQL_CALC_FOUND_ROWS id, erreur FROM Erreurs ORDER BY id DESC LIMIT $limit OFFSET $offset");
        while($row = $result->fetch_assoc()){
            $errorList[] = new Erreur($row);
        }
        $result->free();
        // $foundRows = $result->num_rows; // 25
        $foundRows = $this->con->query("SELECT FOUND_ROWS() as foundRows");
        $this->foundRows = $foundRows->fetch_assoc(); // 178
        return $errorList;
}
?>
justso at inbox dot ru 14-Nov-2015 06:36
in php 5.3.8 had unexpected troubles when checking for mysqli_result::$num_rows
If the result of the query is empty then var_dump of the result will be like this:
class mysqli_result#5 (5) {
  public $current_field => NULL
  public $field_count => NULL
  public $lengths => NULL
  public $num_rows => NULL
  public $type => NULL
}
but var_dump($result->num_rows) will give integer-typed zero instead of NULL:
int(0)
borisigna 08-Aug-2011 05:19
If you have problems making work this num_rows, you have to declare ->store_result() first.

<?php
$mysqli = new mysqli("localhost","root", "", "tables");

$query = $mysqli->prepare("SELECT * FROM table1");
$query->execute();
$query->store_result();

$rows = $query->num_rows;

echo $rows;

// Return 4 for example
?>