使用 PHP 计算 MySQL 中列值的所有值
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Count all values from column values in MySQL using PHP
提问by ?těpán Němejc
回答by Prasannjit
If you want to count the number of columns use:
如果要计算列数，请使用：
Select count(column_name) FROM table name.
If you want the sum of column values then use:
如果您想要列值的总和，请使用：
Select SUM(column_name) FROM table name.
回答by steven
Or maybe SUM is what you really want:
或者也许 SUM 是您真正想要的：
Select SUM(column_name) FROM tablename
回答by Erman Belegu
UPDATE with PHP Code
使用 PHP 代码更新
If you want to count you can do it like this:
如果你想数数，你可以这样做：
$query = "SELECT COUNT(*) FROM table_name"
// Print out result
while($row = mysql_fetch_array($result)){
echo "Total count". $row['COUNT(*)'];
}
If you want to get the sum of one column, you can do like this:
如果你想得到一列的总和，你可以这样做：
$query = "SELECT SUM(column_name) FROM table_name"
// Print out result
while($row = mysql_fetch_array($result)){
echo "Total sum". $row['SUM(column_name)'];
}
回答by Rohan Kumar
Try mysqli_result()like,
尝试mysqli_result() 之类的，
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
if ($result = $mysqli->query("SELECT COUNT(price) as total FROM tablename")) {
/* Get field information for column 'SurfaceArea' */
$finfo = $result->fetch_field_direct(1);
printf("Total price: %s\n", $finfo->total);
$result->close();
}
/* close connection */
$mysqli->close();
?>
回答by Kees Sonnema
You can use this for counting 1 row in your database:
您可以使用它来计算数据库中的 1 行：
<?php
$query = "SELECT COUNT(price) FROM yourtable ";
?>
Then you can use $queryin your code to show the results.
然后你可以$query在你的代码中使用来显示结果。
In mysql (phpmyadmin) you can just do:
在 mysql (phpmyadmin) 中，您可以执行以下操作：
SELECT COUNT(price) FROM yourtable
