mysql資料庫不能添加NULL值,該怎麼解決

mysql資料庫不能添加NULL值
資料都驗證了，但是不能給資料添加NULL值，報錯如下：

Column 'loumiandijia' cannot be null

其他資料在為空白是用NULL都不行

代碼如下

require ('inc/config.php');
$page_title = '住宅資料添加-feige資料中心';
include ('inc/header.php');
require (MYSQL);
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$trimmed = array_map('trim', $_POST);
$errors = array();
if (!empty($trimmed['tudi_id'])) {
$tudi_id = mysqli_real_escape_string ($conn, $trimmed['tudi_id']);
} else {
$errors[] = '地塊編號不可為空';
}
if ( isset($trimmed['city']) && filter_var($trimmed['city'], FILTER_VALIDATE_INT, array('city' => 1)) ) {
$city = mysqli_real_escape_string ($conn, $trimmed['city']);;
} else {
$errors[] = '請選擇地區';
}
$weizhi = (!empty($trimmed['weizhi'])) ? mysqli_real_escape_string ($conn, $trimmed['weizhi']) : NULL;
$yongtu = (!empty($trimmed['yongtu'])) ? mysqli_real_escape_string ($conn, $trimmed['yongtu']) : NULL;
$rongjilv = (!empty($trimmed['rongjilv'])) ? mysqli_real_escape_string ($conn, $trimmed['rongjilv']) : NULL;
$midu = (!empty($trimmed['midu'])) ? mysqli_real_escape_string ($conn, $trimmed['midu']) : NULL;
$lvdi = (!empty($trimmed['lvdi'])) ? mysqli_real_escape_string ($conn, $trimmed['lvdi']) : NULL;
if(empty($trimmed['fabu_time'])) {
$errors[] = '發布日期不可為空';
} else {
$fabu_time = mysqli_real_escape_string ($conn, $trimmed['fabu_time']);
}
if(empty($trimmed['chengjiao_time'])) {
$errors[] = '成交日期不可為空';
} else {
$chengjiao_time = mysqli_real_escape_string ($conn, $trimmed['chengjiao_time']);
}
if(empty($trimmed['jiezhi_time'])) {
$errors[] = '保證金截止時間不可為空';
} else {
$jiezhi_time = mysqli_real_escape_string ($conn, $trimmed['jiezhi_time']);
}
if (is_numeric($trimmed['baozhengjin']) && ($trimmed['baozhengjin'] > 0)) {
$baozhengjin = mysqli_real_escape_string ($conn, (float) $trimmed['baozhengjin']);
} else {
$errors[] = '請輸入一個正確的競買保證金（萬元）';
}
if (is_numeric($trimmed['mianji_m']) && ($trimmed['mianji_m'] > 0)) {
$mianji_m = mysqli_real_escape_string ($conn, (float) $trimmed['mianji_m']);
} else {
$errors[] = '請輸入一個正確的佔地面積（畝）';
}
if (is_numeric($trimmed['mianji_p']) && ($trimmed['mianji_p'] > 0)) {
$mianji_p = mysqli_real_escape_string ($conn, (float) $trimmed['mianji_p']);
} else {
$errors[] = '請輸入一個正確的佔地面積';
}
if (is_numeric($trimmed['guihua_p']) && ($trimmed['guihua_p'] > 0)) {
$guihua_p = mysqli_real_escape_string ($conn, (float) $trimmed['guihua_p']);
} else {
$errors[] = '請輸入一個正確的規劃建築面積';
}
if (is_numeric($trimmed['qipaijia']) && ($trimmed['qipaijia'] > 0)) {
$qipaijia = mysqli_real_escape_string ($conn, (float) $trimmed['qipaijia']);
} else {
$errors[] = '請輸入一個正確的起拍價（萬/畝）';
}
$chengjiaodanjia = (!empty($trimmed['chengjiaodanjia'])) ? mysqli_real_escape_string ($conn, (float) $trimmed['chengjiaodanjia']) : NULL;
$chengjiazongjia = (!empty($trimmed['chengjiazongjia'])) ? mysqli_real_escape_string ($conn, (float) $trimmed['chengjiazongjia']) : NULL;
$loumiandijia = (!empty($trimmed['loumiandijia'])) ? mysqli_real_escape_string ($conn, (float) $trimmed['loumiandijia']) : NULL;
$yijialv = (!empty($trimmed['yijialv'])) ? mysqli_real_escape_string ($conn, $trimmed['yijialv']) : NULL;
$jingderen = (!empty($trimmed['jingderen'])) ? mysqli_real_escape_string ($conn, $trimmed['jingderen']) : NULL;
$churang_p = (!empty($trimmed['churang_p'])) ? mysqli_real_escape_string ($conn, (float) $trimmed['churang_p']) : NULL;
$dituweizhi = (!empty($trimmed['dituweizhi'])) ? mysqli_real_escape_string ($conn, $trimmed['dituweizhi']) : NULL;
$xuzhi = (!empty($trimmed['xuzhi'])) ? mysqli_real_escape_string ($conn, $trimmed['xuzhi']) : NULL;
if ( isset($trimmed['is_cheng']) && is_numeric($trimmed['is_cheng']) && ($trimmed['is_cheng'] >= 0) ) {
$is_cheng = mysqli_real_escape_string ($conn, $trimmed['is_cheng']);;
} else {
$errors[] = '請選擇交易是否成功';
}

if (empty($errors)) {
$q = 'INSERT INTO f_tudi (tudi_id, city_id, weizhi, yongtu, rongjilv, midu, lvdi, fabu_time, chengjiao_time, jiezhi_time, baozhengjin, mianji_m, mianji_p, guihua_p, qipaijia, chengjiaodanjia, chengjiazongjia, loumiandijia, yijialv, jingderen, churang_p, dituweizhi, xuzhi, is_cheng) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)';
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