thinkphp中的select方法與find方法區別

1. find方法源碼，發現find方法只會返回一條記錄，有Limit 限制，並且是一維數組，

2. /**
        * 查詢數據
        * @access public
        * @param mixed $options 表達式參數
        * @return mixed
        */
       public function find($options=array()) {
           if(is_numeric($options) || is_string($options)) {
               $where[$this->getPk()]  =   $options;
               $options                =   array();
               $options['where']       =   $where;
           }
           // 根據複合主鍵查找記錄
           $pk  =  $this->getPk();
           if (is_array($options) && (count($options) > 0) && is_array($pk)) {
               // 根據複合主鍵查詢
               $count = 0;
               foreach (array_keys($options) as $key) {
                   if (is_int($key)) $count++; 
               } 
               if ($count == count($pk)) {
                   $i = 0;
                   foreach ($pk as $field) {
                       $where[$field] = $options[$i];
                       unset($options[$i++]);
                   }
                   $options['where']  =  $where;
               } else {
                   return false;
               }
           }
           // 老是查找一條記錄
           $options['limit']   =   1;
           // 分析表達式
           $options            =   $this->_parseOptions($options);
           // 判斷查詢緩存
           if(isset($options['cache'])){
               $cache  =   $options['cache'];
               $key    =   is_string($cache['key'])?$cache['key']:md5(serialize($options));
               $data   =   S($key,'',$cache);
               if(false !== $data){
                   $this->data     =   $data;
                   return $data;
               }
           }
           $resultSet          =   $this->db->select($options);
           if(false === $resultSet) {
               return false;
           }
           if(empty($resultSet)) {// 查詢結果爲空
               return null;
           }
           if(is_string($resultSet)){
               return $resultSet;
           }
   
           // 讀取數據後的處理
           $data   =   $this->_read_data($resultSet[0]);
           $this->_after_find($data,$options);
           if(!empty($this->options['result'])) {
               return $this->returnResult($data,$this->options['result']);
           }
           $this->data     =   $data;
           if(isset($cache)){
               S($key,$data,$cache);
           }
           return $this->data;
       }

3. select方法源碼，查詢數據集，返回二維數組，配合volist標籤使用！

4. /**
        * 查詢數據集
        * @access public
        * @param array $options 表達式參數
        * @return mixed
        */
       public function select($options=array()) {
           $pk   =  $this->getPk();
           if(is_string($options) || is_numeric($options)) {
               // 根據主鍵查詢
               if(strpos($options,',')) {
                   $where[$pk]     =  array('IN',$options);
               }else{
                   $where[$pk]     =  $options;
               }
               $options            =  array();
               $options['where']   =  $where;
           }elseif (is_array($options) && (count($options) > 0) && is_array($pk)) {
               // 根據複合主鍵查詢
               $count = 0;
               foreach (array_keys($options) as $key) {
                   if (is_int($key)) $count++; 
               } 
               if ($count == count($pk)) {
                   $i = 0;
                   foreach ($pk as $field) {
                       $where[$field] = $options[$i];
                       unset($options[$i++]);
                   }
                   $options['where']  =  $where;
               } else {
                   return false;
               }
           } elseif(false === $options){ // 用於子查詢 不查詢只返回SQL
           	$options['fetch_sql'] = true;
           }
           // 分析表達式
           $options    =  $this->_parseOptions($options);
           // 判斷查詢緩存
           if(isset($options['cache'])){
               $cache  =   $options['cache'];
               $key    =   is_string($cache['key'])?$cache['key']:md5(serialize($options));
               $data   =   S($key,'',$cache);
               if(false !== $data){
                   return $data;
               }
           }        
           $resultSet  = $this->db->select($options);
           if(false === $resultSet) {
               return false;
           }
           if(!empty($resultSet)) { // 有查詢結果
               if(is_string($resultSet)){
                   return $resultSet;
               }
   
               $resultSet  =   array_map(array($this,'_read_data'),$resultSet);
               $this->_after_select($resultSet,$options);
               if(isset($options['index'])){ // 對數據集進行索引
                   $index  =   explode(',',$options['index']);
                   foreach ($resultSet as $result){
                       $_key   =  $result[$index[0]];
                       if(isset($index[1]) && isset($result[$index[1]])){
                           $cols[$_key] =  $result[$index[1]];
                       }else{
                           $cols[$_key] =  $result;
                       }
                   }
                   $resultSet  =   $cols;
               }
           }
   
           if(isset($cache)){
               S($key,$resultSet,$cache);
           }
           return $resultSet;
       }

5. 參考資料

6. http://blog.csdn.net/baronyang/article/details/8674673