这个符号是什么意思<>在PHP的条件语句中?

时间:2015-07-04 13:41:47

标签: php

查看第一个条件// if($ _REQUEST [“string”]<>'')。什么<>这个符号是什这是我第一次看到其中一个。有人可以解释它是什么..提前谢谢

<?php
if ($_REQUEST["string"]<>'') {
    $search_string = " AND (full_name LIKE '%".mysql_real_escape_string($_REQUEST["string"])."%' OR email LIKE '%".mysql_real_escape_string($_REQUEST["string"])."%')"; 
}
if ($_REQUEST["city"]<>'') {
    $search_city = " AND city='".mysql_real_escape_string($_REQUEST["city"])."'";   
}

if ($_REQUEST["from"]<>'' and $_REQUEST["to"]<>'') {
    $sql = "SELECT * FROM ".$SETTINGS["data_table"]." WHERE from_date >= '".mysql_real_escape_string($_REQUEST["from"])."' AND to_date <= '".mysql_real_escape_string($_REQUEST["to"])."'".$search_string.$search_city;
} else if ($_REQUEST["from"]<>'') {
    $sql = "SELECT * FROM ".$SETTINGS["data_table"]." WHERE from_date >= '".mysql_real_escape_string($_REQUEST["from"])."'".$search_string.$search_city;
} else if ($_REQUEST["to"]<>'') {
    $sql = "SELECT * FROM ".$SETTINGS["data_table"]." WHERE to_date <= '".mysql_real_escape_string($_REQUEST["to"])."'".$search_string.$search_city;
} else {
    $sql = "SELECT * FROM ".$SETTINGS["data_table"]." WHERE id>0".$search_string.$search_city;
}

$sql_result = mysql_query ($sql, $connection ) or die ('request "Could not execute SQL query" '.$sql);
if (mysql_num_rows($sql_result)>0) {
    while ($row = mysql_fetch_assoc($sql_result)) {
?>

2 个答案:

答案 0 :(得分:0)

如果你有谷歌它一旦你可能得到相对的答案,然后超过SO

代表 NOT EQUAL

!=

相同

答案 1 :(得分:0)

它是not equal to

与以下相同:

if($a != $b){}

http://php.net/manual/en/language.operators.comparison.php