PHP中mysqli_affected_rows作用行数返回值分析

本文实例分析了php中mysqli_affected_rows作用行数返回值。分享给大家供大家参考。具体分析如下：

mysqli中关于update操作影响的行数可以有两种返回形式:

1. 返回匹配的行数
2. 返回影响的行数

默认情况下mysqli_affected_rows返回的值为影响的行数,如果我们需要返回匹配的行数，可以使用mysqli_real_connect函数进行数据库连接的初始化,并在函数的flag参数位加上:

mysqli_client_found_rows return number of matched rows, not the number of affected rows

普通格式:

int mysqli_affected_rows ( mysqli link )

oop格式：

class mysqli {
int affected_rows
}

看下例子：

普通模式,代码如下:

<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
 
if (!$link) {
printf("can't connect to localhost. error: %sn", mysqli_connect_error());
exit();
}
 
/* insert rows */
mysqli_query($link, "create table language select * from countrylanguage");
printf("affected rows (insert): %dn", mysqli_affected_rows($link));
 
mysqli_query($link, "alter table language add status int default 0″);
 
/* update rows */
mysqli_query($link, "update language set status=1 where percentage > 50″);
printf("affected rows (update): %dn", mysqli_affected_rows($link));
 
/* delete rows */
mysqli_query($link, "delete from language where percentage < 50″);
printf("affected rows (delete): %dn", mysqli_affected_rows($link));
 
/* select all rows */
$result = mysqli_query($link, "select countrycode from language");
printf("affected rows (select): %dn", mysqli_affected_rows($link));
 
mysqli_free_result($result);

/* delete table language */
mysqli_query($link, "drop table language");
 
/* close connection */
mysqli_close($link);
?>

oop模式,代码如下:

<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
 
/* check connection */
if (mysqli_connect_errno()) {
printf("connect failed: %sn", mysqli_connect_error());
exit();
}
 
/* insert rows */
$mysqli->query("create table language select * from countrylanguage");
printf("affected rows (insert): %dn", $mysqli->affected_rows);
 
$mysqli->query("alter table language add status int default 0″);
 
/* update rows */
$mysqli->query("update language set status=1 where percentage > 50″);
printf("affected rows (update): %dn", $mysqli->affected_rows);
 
/* delete rows */
$mysqli->query("delete from language where percentage < 50″);
printf("affected rows (delete): %dn", $mysqli->affected_rows);
 
/* select all rows */
$result = $mysqli->query("select countrycode from language");
printf("affected rows (select): %dn", $mysqli->affected_rows);
 
$result->close();
 
/* delete table language */
$mysqli->query("drop table language");
 
/* close connection */
$mysqli->close();
?>

希望本文所述对大家的php程序设计有所帮助。