我在将数据从索引转换为进程时出错“无法将mysqli_result类的对象转换为int形式”

Question

i got error casting in calculation square distance

i have to make simple sql program but i got problem in casting data

 if (isset($_POST['hitung'])) { $sql = "select * from tb_keterangan"; $result = $conn->query($sql); while ($row = $result->fetch_assoc()) { $d_modal =$conn->query("select modal from tb_keterangan"); $d_lahan =$conn->query("select lahan from tb_keterangan"); $d_indukan =$conn->query("select jumlah_indukan from tb_keterangan"); $d_produksi =$conn->query("select jumlah_produksi from tb_keterangan"); $d_keterangan =$conn->query("select keterangan from tb_keterangan"); $modal =$_POST['modal']; $lahan =$_POST['lahan']; $indukan =$_POST['j_indukan']; $produksi =$_POST['produksi']; $ket =$_POST['keterangan']; $h_modal =($d_modal - (int)$row['modal']); $h_lahan =((int)$d_lahan - (int)$lahan); $h_indukan =((int)$d_indukan - (int)$indukan); $h_produksi =((int)$d_produksi - (int)$produksi); // $h_ket =($d_keterangan - $ket); //pangkat $p_modal =pow($h_modal,2); $p_lahan =pow($h_lahan,2); $p_indukan =pow($h_indukan,2); $p_produksi =pow($h_produksi,2); // $p_ket =pow($h_ket,2); $square_distance = $p_modal+$p_lahan+$p_indukan+$p_produksi; ?> 

but the result calculation is appear

Answer 1

'$d_modal =$conn->query("select modal from tb_keterangan");

These are query variable which you are converting into (int) but you need to get the result from these variables as they are object returned by mysqli query.

Use mysqli_fetch functions and then convert it into int