sqlalchemy和flask-sqlalchemy的幾種分頁方法

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sqlalchemy中使用query查詢，而flask-sqlalchemy中使用basequery查詢，他們是子類與父類的關係

假設 page_index=1,page_size=10；所有分頁查詢不可以再跟first(),all()等

1. 用offset()設定索引位移量,limit()限制取出量

db.session.query(User.name).filter(User.email.like(‘%‘+email+‘%‘)).limit(page_size).offset((page_index-1)*page_size)#filter語句後面可以跟order_by語句

2.用slice( 位移量，取出量)函數

db.session.query(User.name).filter(User.email.like(‘%‘+email+‘%‘)).slice((page_index - 1) * page_size, page_index * page_size)#filter語句後面可以跟order_by語句

注釋：此方法和第一種相同的效果。

因為：由一下內部方法可知，slice()函數第一個屬性就是offset()函數值，第二個屬性就是limit()函數值

@_generative(_no_statement_condition)    def slice(self, start, stop):        """apply LIMIT/OFFSET to the ``Query`` based on a "        "range and return the newly resulting ``Query``."""        if start is not None and stop is not None:            self._offset = (self._offset or 0) + start            self._limit = stop - start        elif start is None and stop is not None:            self._limit = stop        elif start is not None and stop is None:            self._offset = (self._offset or 0) + start        if self._offset == 0:            self._offset = None    @_generative(_no_statement_condition)    def limit(self, limit):        """Apply a ``LIMIT`` to the query and return the newly resulting        ``Query``.        """        self._limit = limit    @_generative(_no_statement_condition)    def offset(self, offset):        """Apply an ``OFFSET`` to the query and return the newly resulting        ``Query``.        """        self._offset = offset

3.用paginate( 位移量，取出量)函數, 用於BaseQuery

user_obj=User.query.filter(User.email.like(‘%‘+email+‘%‘)).paginate(int(page_index), int(page_size),False)#遍曆時要加上items object_list =user_obj.items

 

4. filter中使用limit

db.session.query(User.name).filter(User.email.like(‘%‘+email+‘%‘) and limit (page_index - 1) * page_size, page_size)#此處不能再跟order_by語句，否則報錯

 

 

http://www.cnblogs.com/rgcLOVEyaya/p/RGC_LOVE_YAYA_350days.html

 

sqlalchemy和flask-sqlalchemy的幾種分頁方法