PHP和Mysqli獲取count（distinct（））查詢的值

Question

我在mysql中有一個名為gsm的數據庫表，其中有2列LAC和NAME。

因此，我試圖計算數據庫中存儲了多少個不同的LAC，並檢索了php值以進一步使用。 我正在使用mysqli

我有：

$sql = "select count(distinct lac) from gsm ");

如何將查詢存儲到php中的變量中？

Answer 1

//conection:
$link = mysqli_connect("www.mywebsite.com","user","password","dataname") or die("Error " . mysqli_error($link));

//consultation:
$query = "SELECT COUNT(DISTINCT alias) as visitors FROM Visits where time BETWEEN timestamp(DATE_SUB(NOW(), INTERVAL 1 HOUR)) AND timestamp(NOW())";

//execute the query.
$result = $link->query($query) or die("Error in the consult.." . mysqli_error($link));
$row = mysqli_fetch_array($result);

//display information:
// The text to draw
$text = $row['visitors'];

Answer 2

為了在mysqli中做到這一點，您需要

$count = $DB->query("SELECT COUNT( DISTINCT(LAC)) FROM gsm");
$row = $count->fetch_row();
echo 'LAC appears '. $row[0] . ' times in total.';

因此，現在您可以將$row[0]用於php中需要的其他任何內容。 它是數據庫中LAC的唯一值的數量。

Answer 3

您可以使用下面的代碼進行檢查，但是尚未經過我的測試，但是我確定它可以正常工作。

 # Init the MySQL Connection
    if (!( $db = mysql_connect('localhost', 'root', '') ))
        die ('Failed to connect to MySQL Database Server - #'.mysql_errno ().': '.mysql_error ());
    if (!mysql_select_db('ram'))
        die ('Connected to Server, but Failed to Connect to Database - #'.mysql_errno ().': '.mysql_error ());
    # Prepare the SELECT Query
    $sql = "select count(distinct lac) as LAC from gsm ";
    if (!( $selectRes = mysql_query($sql) )) {
        echo 'Retrieval of data from Database Failed - #' . mysql_errno() . ': ' . mysql_error();
    } else if (mysql_num_rows($selectRes) == 0) {

        echo 'No Any Record Returned';
    } else {
        while ($row = mysql_fetch_assoc($selectRes)) {
            echo $row['LAC'];
        }
    }