mysql / php如果值为空，则忽略设置

Question

Is there anyway to ignore the set CalDate and DueDate if they are null and still succeed to update the values that are entered and save the old value on CalDate and DueDate ?

if(isset($itemID1) && isset($itemID2) && isset($itemID3) && isset($itemID4) && isset($itemID5) && isset($itemID6) && isset($itemID7) && isset($itemID8) && isset($itemID9) && isset($itemID10)){
$upd = "UPDATE booking SET status='$status', CalDate='$CalDate', DueDate='$DueDate' WHERE itemID IN ('$itemID1', '$itemID2', '$itemID3', '$itemID4', '$itemID5', '$itemID6', '$itemID7', '$itemID8','$itemID9', '$itemID10')";
}

This code set a value of 0000-00-00 if null which is understandable but I do like it to ignore that in that case.

Answer 1

try this.

  if(isset($itemID1) && isset($itemID2) && isset($itemID3) && isset($itemID4) && isset($itemID5) && isset($itemID6) && isset($itemID7) && isset($itemID8) && isset($itemID9) && isset($itemID10)){

        $upd = "UPDATE booking SET status='$status'";
        if($CalDate !='')
           $upd.= ",CalDate='$CalDate'";
        if($DueDate !='') 
           $upd .= ",DueDate='$DueDate'";
        $upd .=" WHERE itemID IN ('$itemID1', '$itemID2', '$itemID3', '$itemID4', '$itemID5', '$itemID6', '$itemID7', '$itemID8','$itemID9', '$itemID10')";
        }

Answer 2

if(isset($itemID1) && isset($itemID2) && isset($itemID3) && isset($itemID4) && isset($itemID5) && isset($itemID6) && isset($itemID7) && isset($itemID8) && isset($itemID9) && isset($itemID10)){
    $set = "status = '$status'";
    if ( ! empty($CalDate) ) $set .= ", CalDate = '$CalDate'";
    if ( ! empty($DueDate) ) $set .= ", DueDate = '$DueDate'";
    $upd = "UPDATE booking 
        SET $set 
        WHERE itemID IN ('$itemID1', '$itemID2', '$itemID3', '$itemID4', '$itemID5', '$itemID6', '$itemID7', '$itemID8','$itemID9', '$itemID10')";
}

Answer 3

if(isset($itemID1) && isset($itemID2) && isset($itemID3) && isset($itemID4) && isset($itemID5) && isset($itemID6) && isset($itemID7) && isset($itemID8) && isset($itemID9) && isset($itemID10)){
    $query = "UPDATE booking SET status='$status'";
    if($CalDate != NULL ){
        $query .= ", CalDate='$CalDate'";
        //Run this query to get the CalDate
        //"SELECT CalDate FROM booking WHERE itemID IN ('$itemID1', '$itemID2', '$itemID3', '$itemID4', '$itemID5', '$itemID6', '$itemID7', '$itemID8','$itemID9', '$itemID10')"
        //Get the result into $CalDate
    }
    if($DueDate != NULL ){
        $query .= ", DueDate='$DueDate'";
        //Run this query to get the DueDate
        //"SELECT DueDate FROM booking WHERE itemID IN ('$itemID1', '$itemID2', '$itemID3', '$itemID4', '$itemID5', '$itemID6', '$itemID7', '$itemID8','$itemID9', '$itemID10')"
        //Get the result into $DueDate
    }
    $query .= " WHERE itemID IN ('$itemID1', '$itemID2', '$itemID3', '$itemID4', '$itemID5', '$itemID6', '$itemID7', '$itemID8','$itemID9', '$itemID10')";

    $upd = $query;
}