Question

我想问一下，当它为null时如何输出0？我试过IFNULL和COALESCE，它不起作用。

$this->db->select('produk_tb.kode_produk, produk_tb.nama,  kategori_tb.nama as namakategori');
$this->db->from('produk_tb');

$this->db->join('penjualan_detail_tb', 'produk_tb.kode_produk = penjualan_detail_tb.kode_produk', 'inner');
$this->db->select_sum('penjualan_detail_tb.jumlah','jual');

$this->db->join('pembelian_detail_tb', 'produk_tb.kode_produk = pembelian_detail_tb.kode_produk', 'inner');
$this->db->select_sum('pembelian_detail_tb.jumlah','beli');

$this->db->join('kategori_tb', 'produk_tb.kode_kategori = kategori_tb.kode_kategori', 'inner');

$this->db->group_by('kode_produk');
$kontak = $this->db->get()->result();
$this->response($kontak, 200);

提前致谢

Answer 1

尝试以下

        while(flag == True):

        try:
            price = input("Enter the price: ")
            price = float(price)
            flag = False

            #price must be positive
            if float(price) < 0:
                print("Invalid input for the new price.")
                flag = True

        #check for 2 decimal places
        decimal = str(price)
        decimal = decimal.split(".")
        if len(decimal[1]) != 2:
            print("Invalid input for the new price.")
            flag = True

Answer 2

$ this-＆gt; db-＆gt; select（'select COALESCE（field_name，0）as field_name_alias'）;
$这 - ＆GT; DB-肽从（ 'your_table'）;

尝试这个

CODEIGNITER如果select为NULL，如何输出0？

2 个答案: