如何檢查數據庫中是否存在某個特定的日期

Question

有一張表格，其中有僱員登錄和註銷的日期時間。根據這個日期時間，我必須設置他們的狀態登錄或註銷。我必須在日期時間應用條件，如果日期在數據庫中第一次存在，那麼它將是登錄名，同一日期第二次存在同一日期，然後它將被註銷。

我該怎麼做？

Answer 1

如果我能幫到你，下一個代碼可以幫助你。 （這是一個如何做它的主要思想） 我假設該表是這樣的：

+ workers_logs

• ID
• worker_id
• actiontime
• BLA

我們將有一個名爲workers的數組，其結構爲：

workers[ worker_id ] [0] = 'login' 
workers[ worker_id ] [1] = 'logout' 
workers[ worker_id ] [2] = 'login' 
workers[ worker_id2 ] [0] = 'login' 
workers[ worker_id2 ] [1] = 'logout' 
workers[ worker_id2 ] [2] = 'login' 

//代碼：

$workers = array(); 
$getWorkersLogs = mysql_query("SELECT worker_id,actiontime FROM workers_logs ORDER BY id ASC"); //Notice for: ORDER BY id ASC - it's very imporatnt in your case. 
while($logs = mysql_fetch_array($getWorkersLogs)) 
{ 
if((!array_key_exists($logs['worker_id'] , $workers)) || count($workers[$log['worker_id']]) % 2 == 0) 
{ 
    //This is the first time we are dealing with this worker (so it's login) 
    //or it's an even number. 
     ..... 
     ..... 

    //Add this worker id to our array so next time will be logout 
    $workers[$logs['worker_id']][] = 'login' 
} 
else 
{ 
    $workers[$logs['worker_id']][] = 'logout' 

} 
}