将Excel公式转换为PHP或MySQL查询

=SUM(A1:A10)

SELECT SUM(column_name) FROM table_name WHERE condition;

<?php
$sum = $pdo->query('SELECT SUM(column_name) FROM table_name WHERE condition')->fetchColumn();
echo $sum;
?>

=AVERAGE(B1:B10)

SELECT AVG(column_name) FROM table_name WHERE condition;

<?php
$average = $pdo->query('SELECT AVG(column_name) FROM table_name WHERE condition')->fetchColumn();
echo $average;
?>

=IF(A1>10, "大于10", "小于等于10")

SELECT 
    CASE 
        WHEN column_name > 10 THEN '大于10'
        ELSE '小于等于10'
    END AS result
FROM table_name;

<?php
$stmt = $pdo->query('SELECT 
    CASE 
        WHEN column_name > 10 THEN "大于10"
        ELSE "小于等于10"
    END AS result
FROM table_name');
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);
foreach ($results as $row) {
    echo $row['result'] . "\n";
}
?>

<?php
// 假设column_name是字符串类型，需要转换为数值类型
$stmt = $pdo->query('SELECT CAST(column_name AS DECIMAL(10,2)) AS numeric_column FROM table_name');
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);
foreach ($results as $row) {
    echo $row['numeric_column'] . "\n";
}
?>

-- 使用索引优化查询
CREATE INDEX idx_column_name ON table_name(column_name);