rows作用行数返回值分析

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:

复制代码 代码如下:

int mysqli_affected_rows ( mysqli link )

oop格式：

复制代码 代码如下:

class mysqli {
int affected_rows
}

看下例子：

普通模式,代码如下:

复制代码 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:

复制代码 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();
?>