如果表为空,则CodeIgniter result_array()出现布尔错误

Question

我在我的这个功能Carros_model.php用于带来最后一次插入并在仪表板中显示它们:

public function select_all($limit = 3)
{
    $this->db
        ->select('marca.nome_marca,'
               . 'combustivel.nome_combustivel,'
               . 'cambio.descricao_cambio,'
               . 'DATE_FORMAT(carro.data_criacao, "%d/%m/%Y") as criacao,'
               . 'DATE_FORMAT(carro.data_modificacao, "%d/%m/%Y") as modificacao,'
               . 'carro.*')
        ->from('carro')
        ->join('marca', 'marca.id = carro.id_marca')
        ->join('combustivel', 'combustivel.id = carro.id_combustivel')
        ->join('cambio', 'cambio.id = carro.id_cambio')
        ->order_by('carro.id', 'DESC')
        ->limit($limit, 0);

    $query = $this->db->get();

    foreach ($query->result_array() as $row) {
        $data[] = $row;
    }

    $query->free_result();

    return $data;
}

它工作正常,但我发现,如果表是空的,错误

致命错误:在布尔值上调用成员函数result_array()

被扔了.我该如何解决这个问题？

Answer 1

在尝试获取结果之前,您应该检查查询是否有效/有任何行.如果表为空,则查询将不执行任何操作.

$query = $this->db->get();

$data = array();
if($query !== FALSE && $query->num_rows() > 0){
    foreach ($query->result_array() as $row) {
        $data[] = $row;
    }
}

return $data;

PS没有理由使用循环$query->result_array(),你可以返回.它已经是一排行.

$query = $this->db->get();

$data = array();
if($query !== FALSE && $query->num_rows() > 0){
    $data = $query->result_array();
}

return $data;