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Limiting while loop

开发者 https://www.devze.com 2022-12-16 19:08 出处:网络
Is there a way to limiting while loops when fetching data from mysql ? $query = \"SELECT * FROM`table`

Is there a way to limiting while loops when fetching data from mysql ?

$query = "SELECT * 
    FROM  `table` 
    WHERE user_id = '$id' 
    ORDER BY `ID` DESC";

$result = mysql_query($query);

while ($info = mysql_fetch_assoc($result)) {
    //stuff
}

Here i dont want to use mysql's LIMIT function, can i lim开发者_JAVA技巧it while loop other than that one ?

Thanks


You can always break the loop when it reaches its target. Otherwise you can use a for loop as Nick suggested.

$count = 0;

while ($count < 4 && $info = mysql_fetch_assoc($result)) {
    //stuff

    $count++;
}

However note that it may be a better idea to limit the result-set from the query with the LIMIT command.


Use a for loop. For example, to loop through up to five rows...

for ($i = 0; $info = mysql_fetch_assoc($result) && $i < 5; ++$i) {
    // do stuff
}


Just add a check for the number of rows:

while ($rowcount < 100 && $info = mysql_fetch_assoc($result)) {
    $rowcount += 1;
//stuff
}


You can use break to end a loop.

So, it could be

$result = mysql_query($query);
$count=0;

while ($info = mysql_fetch_assoc($result)) {

if($info=="what you're looking for"){ $count+=1; }

if($count >= 4){ break; }//break will exit the while loop
}

break php docs


You can always jump out of your PHP loop early - but you should be using the mysql LIMIT clause for this - the entire result set is fetched from the database and transfered to the client when you call mysql_query() potentially creating memory and performance problems.

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