doure8758 2015-07-08 15:25
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PHP使用for循环来迭代MySQLi记录集

Whenever I am working with PHP MySQLi recordsets, I have always worked with the returned data using the standard while loop to iterate over the recordset. Recently, however, I started wondering if there is a way to use a for loop instead. This would be handy in situations where you want to limit the number of results returned.


Here is an example of using the while loop:

//Prepare a query that will produce a reverse-order recordset
$sql = "SELECT * FROM tblNames ORDER BY numberID DESC";
$recordset = $conn -> query($sql);

//Count the number of contacts added to the list
$contactCount = 0;

while($row = $recordset -> fetch_assoc())
{   
    //If the list has reached its maximum number (5), end the display loop
    if($contactCount >= 5)
    {
        break;
    }

    $contactList .= $row["name"] . "<br>";

    //Increment the number of contacts added to the list
    $contactCount ++;
}

//Use '$contactList' somewhere....
echo($contactList);

While this definitely works, there must be a better way to end the loop after a specified number of iterations. Is it easier to use a for loop in a situation like this? If so, how?

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  • dopod0901 2015-07-08 15:38
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    You can use LIMIT in the query. For example:

    SELECT * FROM tblNames ORDER BY numberID DESC LIMIT 15
    

    This way you don't have to worry about what happens if your query does return less than 15 results.

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