php教程

php手册

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

mysqli_num_rows ( mysqli_result $result ) : int

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

mysqli_affected_rows() - Gets the number of affected rows in a previous MySQL operation
mysqli_store_result() - 转移上一次查询返回的结果集
mysqli_use_result() - Initiate a result set retrieval
mysqli_query() - 对数据库执行一次查询

User Contributed Notes

Amos 'D Great 08-Sep-2017 09:11


// 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 13-Aug-2017 09:18


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 02:56


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 09:36


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 07-Aug-2011 08:19


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

?>

php教程 php手册 php手册

mysqli_result::$num_rows

mysqli_num_rows

说明

参数

返回值

范例

参见

User Contributed Notes

php教程

php手册