CI对数据库的常用操作

/* ================================== 查询 $query = $this->db_query("SELECT * FROM table"); ==================================*///result() 返回对象数组$data = $query->result();//result_array() 返回数据 $data = $query->result_array();//row() 只返回一行对象数组$data = $query->row();//num_rows() 返回查询结果行数$data = $query->num_rows();//num_fields() 返回查询请求的字段个数$data = $query->num_fields();//row_array() 只返回一行数组$data = $query->row_array();//free_result() 释放当前查询所占用的内存并删除关联资源标识$data = $query->free_result();/* ================================== 插入操作 ==================================*///上次插入操作生成的IDecho $this->db->insert_id();//写入和更新操作被影响的行数echo $this->db->affected_rows();//返回指定表的总行数echo $this->db->count_all('table_name');//输出当前的数据库版本号echo $this->db->version();//输出当前的数据库平台echo $this->db->platform();//返回最后运行的查询语句echo $this->db->last_query();//插入数据，被插入的数据会被自动转换和过滤，例如：//$data = array('name' => $name, 'email' => $email, 'url' => $url);$this->db->insert_string('table_name', $data);/* ================================== 更新操作 ==================================*///更新数据，被更新的数据会被自动转换和过滤，例如：//$data = array('name' => $name, 'email' => $email, 'url' => $url);//$where = "author_id = 1 AND status = 'active'";$this->db->update_string('table_name', $data, $where);/* ================================== 选择数据 ==================================*///获取表的全部数据$this->db->get('table_name');//第二个参数为输出条数，第三个参数为开始位置$this->db->get('table_name', 10, 20);//获取数据，第一个参数为表名，第二个为获取条件，第三个为条数$this->db->get_where('table_name', array('id'=>$id), $offset);//select方式获取数据$this->db->select('title, content, date');$data = $this->db->get('table_name');//获取字段的最大值，第二个参数为别名，相当于max(age) AS nianling$this->db->select_max('age');$this->db->select_max('age', 'nianling');//获取字段的最小值$this->db->select_min('age');$this->db->select_min('age', 'nianling');//获取字段的和$this->db->select_sum('age');$this->db->select_sum('age', 'nianling');//自定义from表$this->db->select('title', content, date');$this->db->from('table_name');//查询条件 WHERE name = 'Joe' AND title = 'boss' AND status = 'active'$this->db->where('name', $name);$this->db->where('title', $title);$this->db->where('status', $status);//范围查询$this->db->where_in('item1', 'item2');$this->db->where_not_in('item1', 'item2');//匹配，第三个参数为匹配模式 title LIKE '%match%'$this->db->like('title', 'match', 'before/after/both');$this->db->not_like();//分组 GROUP BY title, date$this->db->group_by('title', 'date');//限制条数$this->db->limit(0, 20);//这个函数会检测数据类型，仅转义字符串类型的数据。 它会自动用单引号将你的数据括起来，你不用手动添加。$this->db->escape();For example:>$sql="insert into table(title)values(".$this->db ->escape($title).")";

转载地址 ： http://blog.csdn.net/newjueqi/article/details/7803033