我在dr_scan表中有scan_freq列。我试图将记录插入dr_scan表，如果有任何重复的值，它将把重复的行scan_freq列改为0，否则它保持1。
所以我开发了下面提到的代码，它像我预期的那样工作。但是当我试图一次插入多个记录时，它会返回“subquery returns more than 1 row when insert multiple records at once”

if ($savec == "confirm") 
{ 
    $checkIfExistsQuery = "SELECT COUNT(*) as count FROM dr_scan WHERE barcode = (SELECT barcode FROM temp_scan_save WHERE user_id='$user_id' )"; 
    $checkResult = mysqli_query($conn, $checkIfExistsQuery); 
    $rowCount = mysqli_fetch_assoc($checkResult)['count']; 
    if ($rowCount > 0) 
    {
         $updateSql = "UPDATE dr_scan SET scan_freq = 0 WHERE barcode = (SELECT barcode FROM temp_scan_save WHERE user_id='$user_id' )"; 
         $updateResult = mysqli_query($conn, $updateSql); 
     } 
        $insertSql = "INSERT INTO dr_scan (barcode, machine_type, line, date, user_id, device_id, center, mstatus, mstatus_changed, live_status, transfer_status, scan_freq) SELECT barcode, machine_type, line, date, user_id, device_id, center, mstatus, mstatus_changed, live_status, transfer_status, 1 as scan_frequency FROM temp_scan_save WHERE user_id='$user_id'"; 
        $insertResult = mysqli_query($conn, $insertSql); 
        if (isset($updateResult) && $updateResult && isset($insertResult) && $insertResult)
         { $response = array("response" => "success"); echo json_encode($response); 
        } else 
        { 
            $response = array("response" => "failure"); echo json_encode($response);
         } 
         $sql2 = "DELETE FROM temp_scan_save WHERE user_id='$user_id' "; $result2 = mysqli_query($conn, $sql2); } 
         else { }
mysqli_close($conn);

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