codeIgniter3 学习笔记十（数据库操作）

Posted 2022-03-08 岁月可贵

数据库操作

class Db extends CI_Controller

    public function __construct()
    
        parent::__construct();
        $this->load->database();
    
    // 多结果查询（对象形式）
    public function select_object()
    
        $query = $this->db->query('SELECT * FROM user');
        foreach ($query->result() as $row)
        
            echo $row->id;
            echo $row->user;
            echo $row->password;
            echo "<br/>";
        
    
    // 多结果查询（数组形式）
    public function select_array()
    
        $query = $this->db->query('SELECT * FROM user');
        foreach ($query->result_array() as $row)
        
            echo $row['id'];
            echo $row['user'];
            echo $row['password'];
            echo "<br/>";
        
    
    // 单结果查询（对象形式）
    public function select_limit_object()
    
        $query = $this->db->query('SELECT * FROM user LIMIT 1');
        $row = $query->row();
        echo $row->id;
        echo $row->user;
        echo $row->password;
    
    // 单结果查询（数组形式）
    public function select_limit_array()
    
        $query = $this->db->query('SELECT * FROM user LIMIT 1');
        $row = $query->row_array();
        echo $row['id'];
        echo $row['user'];
        echo $row['password'];
    
    // 插入数据
    public function insert()
    
        $user = "好好";
        $password = "浩浩";
        $sql = "INSERT INTO user (user, password) VALUES (".$this->db->escape($user).", ".$this->db->escape($password).")";
        $this->db->query($sql);
        echo $this->db->affected_rows();
    
    // 构造器模式查询
    public function construct_select()
    
        $query = $this->db->get("user");
        foreach ($query->result() as $item) 
            echo $item->id;
            echo $item->user;
            echo $item->password;
            echo "<br>";
        
    
    // 构造器模式插入
    public function construct_insert()
    
        $user = "测试";
        $password = "测试";
        $data = array(
            'user' => $user,
            'password' => $password,
        );
        $this->db->insert('user', $data);