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我有一個包含很多字段的表,並且我需要爲每個字段返回NOT NULL的COUNT。選擇COUNT,其中字段NOT NULL,表中的每個字段
我做PHP中的循環,我執行由場1名的請求......
$result = array();
$champs = array("field1", "field2", "field3", "field4", "field5", "field6", "field7", "field8", "field9", "field10", "field11", "field12", "field13", "field14", "field15", "field16", "field17", "field18", "field19", "field20");
foreach ($champs as $value) {
$and = empty($filtroAdd) ? "$value IS NOT NULL" : "AND $value IS NOT NULL";
$requete = "SELECT COUNT($value)
FROM my_table
WHERE $filtroAdd $and";
$r = $db->query($requete)->fetch(PDO::FETCH_NUM);
$result[$value] = $r[0];
}
print_r($result);
我想是不是更好的辦法,我們當然可以用一個PostgreSQL的請求返回相同的最終結果?!
感謝您的幫助
'COUNT()'已經排除了NULL值。見http://www.techonthenet.com/postgresql/functions/count.php,所以你可以有一個'SELECT'和多個'COUNT(...)' –