如何用php获取mysql数据库的行数
我想通过一条语句或一个函数获得mysql数据库表的行数如何用php获取mysql数据库的行数,php,mysql,sql,database,Php,Mysql,Sql,Database,我想通过一条语句或一个函数获得mysql数据库表的行数 include "opendatabase.php"; //opens database while (NUMBEROFROWS > 0){ //do something } function getRowNumber(){ $query = "SELECT COUNT(*) FROM `votes`"; $result = mysql_query($query, $connect); list
include "opendatabase.php"; //opens database
while (NUMBEROFROWS > 0){
//do something
}
function getRowNumber(){
$query = "SELECT COUNT(*) FROM `votes`";
$result = mysql_query($query, $connect);
list($length) = mysql_fetch_row($result);
return $length;
}
NUMBEROFROWS
应替换为返回行数的语句
我已经尝试创建一个函数
include "opendatabase.php"; //opens database
while (NUMBEROFROWS > 0){
//do something
}
function getRowNumber(){
$query = "SELECT COUNT(*) FROM `votes`";
$result = mysql_query($query, $connect);
list($length) = mysql_fetch_row($result);
return $length;
}
但是如果我不把包含在“opendatabase.php”中,它就不起作用代码>在其中
我做错了什么给你:
function num(){
$data = mysql_query("SELECT * FROM table");
if(mysql_num_rows($data) > 0){
while($row = mysql_fetch_assoc($data)){
// do something with your data..
}
}
}
这对你有用吗
function getRowNumber()
{
$query = "SELECT COUNT(*) as counts FROM `votes`";
$result = mysql_query($query, $connect);
$row = mysql_fetch_array($result);
$counts = $row['counts'];
return $counts;
}
问题是包含“opendatabase.php”代码>在另一个作用域中运行,如此处所述
函数中缺少一个global$connect
,在opendatabase.php
中初始化数据库连接,并将连接链接作为参数传递给函数。这是一个范围问题。您的数据库连接应该是全局的(不建议这样做),或者通过函数本身传递。当您不使用include“opendatabase.php”时,会出现什么错误代码>
$result = mysql_query("SELECT * FROM tablename");
if (mysql_num_rows($result) > 0) {
// rows found..
}