網(wǎng)上倒是有不少Codeigniter數(shù)據(jù)庫操作的介紹，這個(gè)是比較全的了。

查詢
 

 $query = $this->db_query("SELECT * FROM table");
 ==================================
*/
 
//result() 返回對(duì)象數(shù)組
$data = $query->result();
 
//result_array() 返回?cái)?shù)據(jù)
$data = $query->result_array();
 
//row() 只返回一行對(duì)象數(shù)組
$data = $query->row();
 
//num_rows() 返回查詢結(jié)果行數(shù)
$data = $query->num_rows();
 
//num_fields() 返回查詢請求的字段個(gè)數(shù)
$data = $query->num_fields();
 
//row_array() 只返回一行數(shù)組
$data = $query->row_array();
 
//free_result() 釋放當(dāng)前查詢所占用的內(nèi)存并刪除關(guān)聯(lián)資源標(biāo)識(shí)
$data = $query->free_result();
 
/*
 ==================================
 插入操作
 ==================================
*/
 
//上次插入操作生成的ID
echo $this->db->insert_id();
 
//寫入和更新操作被影響的行數(shù)
echo $this->db->affected_rows();
 
//返回指定表的總行數(shù)
echo $this->db->count_all('table_name');
 
//輸出當(dāng)前的數(shù)據(jù)庫版本號(hào)
echo $this->db->version();
 
//輸出當(dāng)前的數(shù)據(jù)庫平臺(tái)
echo $this->db->platform();
 
//返回最后運(yùn)行的查詢語句
echo $this->db->last_query();
 
//插入數(shù)據(jù)，被插入的數(shù)據(jù)會(huì)被自動(dòng)轉(zhuǎn)換和過濾，例如：
//$data = array('name' => $name, 'email' => $email, 'url' => $url);
$this->db->insert_string('table_name', $data);
 
/*
 ==================================
 更新操作
 ==================================
*/
 
//更新數(shù)據(jù)，被更新的數(shù)據(jù)會(huì)被自動(dòng)轉(zhuǎn)換和過濾，例如：
//$data = array('name' => $name, 'email' => $email, 'url' => $url);
//$where = "author_id = 1 AND status = 'active'";
$this->db->update_string('table_name', $data, $where);
 
/*
 ==================================
 選擇數(shù)據(jù)
 ==================================
*/
 
//獲取表的全部數(shù)據(jù)
$this->db->get('table_name');
 
//第二個(gè)參數(shù)為輸出條數(shù)，第三個(gè)參數(shù)為開始位置
$this->db->get('table_name', 10, 20);
 
//獲取數(shù)據(jù)，第一個(gè)參數(shù)為表名，第二個(gè)為獲取條件，第三個(gè)為條數(shù)
$this->db->get_where('table_name', array('id'=>$id), $offset);
 
//select方式獲取數(shù)據(jù)
$this->db->select('title, content, date');
$data = $this->db->get('table_name');
 
//獲取字段的最大值，第二個(gè)參數(shù)為別名，相當(dāng)于max(age) AS nianling
$this->db->select_max('age');
$this->db->select_max('age', 'nianling');
 
//獲取字段的最小值
$this->db->select_min('age');
$this->db->select_min('age', 'nianling');
 
//獲取字段的和
$this->db->select_sum('age');
$this->db->select_sum('age', 'nianling');
 
//自定義from表
$this->db->select('title', content, date');
$this->db->from('table_name');
 
//查詢條件 WHERE name = 'Joe' AND title = "boss" AND status = 'active'
$this->db->where('name', $name);
$this->db->where('title', $title);
$this->db->where('status', $status);
 
//范圍查詢
$this->db->where_in('item1', 'item2');
$this->db->where_not_in('item1', 'item2');
 
//匹配，第三個(gè)參數(shù)為匹配模式 title LIKE '%match%'
$this->db->like('title', 'match', 'before/after/both');