PHP框架CodeIgniter的数据库操作整理

1.
$query = $this->db->query('SELECT name, title, email from my_table');
foreach ($query->result() as $row)
{
    echo $row->title;
    echo $row->name;
    echo $row->email;
}
2.
foreach ($query->result_array() as $row)
{
    echo $row['title'];
    echo $row['name'];
    echo $row['email'];
}
3.
if ($query->num_rows() > 0)
4.
$query = $this->db->query('SELECT name from my_table LIMIT 1');
$row = $query->row();//$row = $query->row_array();
echo $row->name;
你可以传递参数以便获得某一行的数据。比如我们要获得第 5 行的数据：
$row = $query->row_array(5);
除此以外, 我们还可以使用下面的方法通过游标的方式获取记录：
$row = $query->first_row()
$row = $query->last_row()
$row = $query->next_row()
$row = $query->previous_row()
5.
$sql = "INSERT INTO mytable (title, name)
        VALUES (".$this->db->escape($title).", ".$this->db->escape($name).")";
$this->db->query($sql);//$query = $this->db->get('table_name');
echo $this->db->affected_rows();
6.
$data = array(
               'title' => $title,
               'name' => $name,
               'date' => $date
            );
$this->db->insert('mytable', $data);
// Produces: INSERT INTO mytable (title, name, date) VALUES ('{$title}', '{$name}', '{$date}')
7.
$this->db->escape()
8.
$sql = "SELECT * from some_table WHERE id = ? AND status = ? AND author = ?";
$this->db->query($sql, array(3, 'live', 'Rick')); //自动转义
9.
该函数返回当前请求的字段数（列数）：
$query = $this->db->query(