mysqli_result::$num_rows
mysqli_num_rows
(PHP 5, PHP 7, PHP 8)
mysqli_result::$num_rows -- mysqli_num_rows — Gets the number of rows in the result set
说明
面向对象风格
过程化风格
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.
This function returns 0 for unbuffered result sets unless
all rows have been fetched from the server.
参数
-
result -
仅以过程化样式：由 mysqli_query()、mysqli_store_result()、 mysqli_use_result()、mysqli_stmt_get_result() 返回的 mysqli_result 对象。
返回值
An int representing the number of fetched rows.
Returns 0 in unbuffered mode unless all rows have been
fetched from the server.
注意:
If the number of rows is greater than
PHP_INT_MAX, the number will be returned as a string.
范例
示例 #1 面向对象风格
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$result = $mysqli->query("SELECT Code, Name FROM Country ORDER BY Name");
/* Get the number of rows in the result set */
$row_cnt = $result->num_rows;
printf("Result set has %d rows.\n", $row_cnt);
示例 #2 过程化风格
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
$result = mysqli_query($link, "SELECT Code, Name FROM Country ORDER BY Name");
/* Get the number of rows in the result set */
$row_cnt = mysqli_num_rows($result);
printf("Result set has %d rows.\n", $row_cnt);
以上例程会输出：
Result set has 239 rows.
注释
注意:
In contrast to the mysqli_stmt_num_rows() function, this function doesn't have object-oriented method variant. In the object-oriented style, use the getter property.
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
- mysqli_stmt_num_rows() - Returns the number of rows fetched from the server
add a note
User Contributed Notes 3 notes
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
?>
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 $errorList;
}
?>
in php 5.3.8 had unexpected troubles when checking for mysqli_result::$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)
备份地址：http://www.lvesu.com/blog/php/mysqli-result.num-rows.php