使用 php 和 mysql 计算总值而不是行

Question

我正在尝试计算收集的令牌总数，而不是mysql数据库中的记录数。虽然我已经将SUM函数放在查询中，但它仍然计算no。行数。

<?php 

   $conn = mysqli_connect(server, dbuser, dbpw, db);

   $query = " SELECT SUM(nooftokensused) FROM bidding WHERE biddedon >= DATE_FORMAT(CURRENT_DATE(), '%Y-01-01') GROUP BY biddingid";

   $query_run = mysqli_query($conn, $query);

   $row = mysqli_num_rows($query_run); 

   echo '<h1>'.$row.'</h1>';

?>

Answer 1

我已经在我的代码中添加了注释。此外，您正在使用 ，您尚未将它们声明为带有符号的变量。mysqli_connect(server, dbuser, dbpw, db)$<?php&nbsp; &nbsp; //Make connection with DB&nbsp; &nbsp; $con = mysqli_connect($server, $dbuser, $dbpw, $db);&nbsp; &nbsp; if (mysqli_connect_errno()) {&nbsp; &nbsp; &nbsp; echo "Failed to connect to MySQL: " . mysqli_connect_error();&nbsp; &nbsp; &nbsp; exit();&nbsp; &nbsp; }&nbsp; &nbsp; $sql = "SELECT SUM(nooftokensused) as summ FROM bidding WHERE biddedon >= DATE_FORMAT(CURRENT_DATE(), '%Y-01-01') GROUP BY biddingid";&nbsp; &nbsp; $result = mysqli_query($con, $sql);&nbsp; &nbsp; if(mysqli_num_rows($result)>0)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; // Associative array&nbsp; &nbsp; &nbsp; &nbsp; $row = mysqli_fetch_assoc($result);&nbsp; &nbsp; &nbsp; &nbsp; echo $row["summ"];&nbsp; &nbsp; }&nbsp; &nbsp; else&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; echo 0;&nbsp; &nbsp; }&nbsp; &nbsp; // Free result set&nbsp; &nbsp; mysqli_free_result($result);&nbsp; &nbsp; mysqli_close($con);&nbsp; &nbsp; ?>

Answer 2

使用 mysqli_fetch_assoc（） 而不是 mysqli_num_rows（）。<?php&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $conn = mysqli_connect(server, dbuser, dbpw, db);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $query = " SELECT SUM(value_sum) AS nooftokensused FROM bidding WHERE biddedon >= DATE_FORMAT(CURRENT_DATE(), '%Y-01-01') GROUP BY biddingid";&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $query_run = mysqli_query($conn, $query);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; $row = mysqli_fetch_assoc($query_run);&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; echo '<h1>'.$row['nooftokensused'].'</h1>';&nbsp;?>