用codeigniter也有一段时间了，一直没有做什么总结。 昨日乱逛，看到有同学总结了一下ci的数据库操作，虽说不全，但是也确实可以帮助那些刚刚上手CI的同学。

链接数据库

$this->load->database();//手动连接数据库 //连接多数据库 $DB1 = $this->load->database(‘group_one’, TRUE); $DB2 = $this->load->database(‘group_two’, TRUE);

查询

//参数绑定形式 $sql = “SELECT * FROM some_table WHERE id = ? AND status = ? AND author = ?"; $this->db->query($sql, array(3, ‘live’, ‘Rick’));

//多结果标准查询 $query = $this->db->query($sql); //自定义 $query = $this->db->get(‘tablename’); //便捷形式，相当于:SELECT * FROM tablename $query = $this->db->get(‘tablename’, 10, 20); // 相当于: SELECT * FROM tablename LIMIT 20, 10

$query->result() //对象形式 $query->result_array() //数组形式 /* foreach ($query->result() as $row) { echo $row->title; echo $row->name; echo $row->email; } */ $query->num_rows() //总条数 $query->num_fields() //字段数

//单结果标准查询 $row = $query->row(); //对象形式 $row = $query->row_array(); //数组形式 /* $row = $query->row_array(); echo $row[‘name’]; */

插入

$data = array( ‘title’ => $title, ‘name’ => $name ); $this->db->insert(‘tablename’, $data); //便捷插入 $this->db->insert_string(‘tablename’, $data); //便捷插入

$this->db->insert_id() //刚插入的id $this->db->affected_rows() //影响的行数(update,insert)

更新

$data = array( ‘name’ => $name, ‘email’ => $email ); $where = “id = 1”; $this->db->update(‘tablename’, $data); $this->db->update_string(‘tablename’, $data, $where);

删除

$array = array( ‘name’ => $name, ‘title’ => $title ); $this->db->delete(‘tablename’, $array);

// Produces: // “DELETE FROM tablename WHERE name = ‘$name’ AND title = ‘$title’”

$this->db->truncate(‘tablename’); //清空表 // Produce: TRUNCATE tablename

（where）

$array = array( ‘name’ => $name, ‘title’ => $title ); $this->db->where($array); // Produces: “WHERE name = ‘$name’ AND title = ‘$title’”

$this->db->count_all(‘tablename’); //表中记录总行数

$query->free_result() //释放资源 出处：http://www.linvo2008.cn/blog/?p=437

最后修改于 2009-02-19