php獲取數據庫表的搜索結果號碼

Question

我希望能夠獲得我的數據庫的特定表中的搜索結果數量（讓我們將其命名爲wp_postmeta）。例如，如果我搜索的確切短語「星期三（9月3日）」，我希望能夠通過php獲得搜索結果的數量。

數據庫的例子

meta_id|post_id|meta_key   |meta_value 

1  |123 |delivery-schedule |Wednesday (3 Sep) 
2  |124 |delivery-schedule |Wednesday (3 Sep) 
3  |125 |delivery-schedule |Thursday (4 Sep) 
4  |126 |delivery-schedule |Friday (5 Sep) 
5  |127 |delivery-schedule |Wednesday (3 Sep) 

因此，在這種情況下，我應該得到的結果作爲3。對不起，如果這聽起來太簡單了但我無法在任何地方找到我的答案。謝謝！

< - 這是我基於gihanmu建議嘗試 - >

function test1() { 
    $variable = "Wednesday(3 Sep)"; 
    $sql = "SELECT COUNT(*) FROM wp_postmeta WHERE meta_value='".$variable."'"; 
    //In your example $variable is Wednesday(3 Sep) 
    $result=mysqli_query($connection,$sql); 
    $count_array=mysqli_fetch_array($result); 
    $exact_count=array_shift($count); 
    echo $exact_count; 
} 
add_action('woocommerce_before_order_notes', 'test1'); 

Answer 1

$sql = "SELECT COUNT(*) FROM wp_postmeta WHERE meta_value='".$variable."'"; 
//In your example $variable is Wednesday(3 Sep) 
$result=mysqli_query($connection,$sql); 
$count_array=mysqli_fetch_array($result); 
$exact_count=array_shift($count); 

$ count_array是一個數組，所以你要拉的第一個元素進行使用array_shift（）函數來獲取$ exact_count

Answer 2

SELECT COUNT(meta_id) FROM wp_postmeta WHERE meta_value = 'Wednesday (3 Sep)'; 

但由於您使用的PHP，你將需要mysqli的;也許是這樣的

$mysqli = new mysqli("localhost", "user", "password", "database"); 
$mydate = 'Wednesday (3 Sep)'; 
$stmt = $mysqli->prepare("SELECT COUNT(meta_id) FROM wp_postmeta WHERE meta_value = ?"); 
$stmt->bind_param('s', $mydate); 
$result = $stmt->execute(); 
$stmt->bind_result($col1); 
while ($stmt->fetch()) { 
    echo "you have {$col1} rows matching $mydate\n"; 
}