Yii Framework 开发教程(28) Data Provider 简介

快来打我* 2023-10-16 19:18 2阅读 0赞

这开始介绍Zii组件之前，先简要介绍一下Yii支持的数据源接口 IDataProvider，IDataProvider主要功能是为UI组件如GridView，ListView等提供数据源，同时也支持数据的分页和排序。下图为Yii内置的三种数据源：

*  CActiveDataProvider 基于Active Record的数据源
 *  CArraryDataProvider 基于数组的数据源
 *  CSqlDataProvider 基于SQL查询的数据源

[![201212128001][]][201212128001 1]

三种Data Provider的使用大同小异：

CActiveDataProvider 基于ActiveRecord, 它通过AR的 [CActiveRecord::findAll][CActiveRecord_findAll]方法读取数据库记录，并通过 [criteria][]属性设置查询条件。

如：

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1.  $dataProvider=new CActiveDataProvider('Post', array(
2.  'criteria'=>array(
3.  'condition'=>'status=1',
4.  'order'=>'create\_time DESC',
5.  'with'=>array('author'),
6.  ),
7.  'pagination'=>array(
8.  'pageSize'=>20,
9.  ),
10. ));
11. // $dataProvider->getData() will return a list of Post objects

$dataProvider=new CActiveDataProvider('Post', array(
        'criteria'=>array(
            'condition'=>'status=1',
            'order'=>'create_time DESC',
            'with'=>array('author'),
        ),
        'pagination'=>array(
            'pageSize'=>20,
        ),
    ));
    // $dataProvider->getData() will return a list of Post objects

CArrayDataProvider 基于数组，其中属性 [rawData][] 设置原始数据，一般为数组或者DAO查询结果，如：

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1.  $rawData=Yii::app()->db->createCommand('SELECT \* FROM tbl\_user')->queryAll();
2.  // or using: $rawData=User::model()->findAll();
3.  $dataProvider=new CArrayDataProvider($rawData, array(
4.  'id'=>'user',
5.  'sort'=>array(
6.  'attributes'=>array(
7.  'id', 'username', 'email',
8.  ),
9.  ),
10. 'pagination'=>array(
11. 'pageSize'=>10,
12. ),
13. ));
14. // $dataProvider->getData() will return a list of arrays.

$rawData=Yii::app()->db->createCommand('SELECT * FROM tbl_user')->queryAll();
    // or using: $rawData=User::model()->findAll();
    $dataProvider=new CArrayDataProvider($rawData, array(
        'id'=>'user',
        'sort'=>array(
            'attributes'=>array(
                 'id', 'username', 'email',
            ),
        ),
        'pagination'=>array(
            'pageSize'=>10,
        ),
    ));
    // $dataProvider->getData() will return a list of arrays.

CSqlDataProvider 基于SQL查询，通过设置  [sql][] 语句来配置，比如：

**\[php\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  $count=Yii::app()->db->createCommand('SELECT COUNT(\*) FROM tbl\_user')->queryScalar();
2.  $sql='SELECT \* FROM tbl\_user';
3.  $dataProvider=new CSqlDataProvider($sql, array(
4.  'totalItemCount'=>$count,
5.  'sort'=>array(
6.  'attributes'=>array(
7.  'id', 'username', 'email',
8.  ),
9.  ),
10. 'pagination'=>array(
11. 'pageSize'=>10,
12. ),
13. ));
14. // $dataProvider->getData() will return a list of arrays.

$count=Yii::app()->db->createCommand('SELECT COUNT(*) FROM tbl_user')->queryScalar();
    $sql='SELECT * FROM tbl_user';
    $dataProvider=new CSqlDataProvider($sql, array(
        'totalItemCount'=>$count,
        'sort'=>array(
            'attributes'=>array(
                 'id', 'username', 'email',
            ),
        ),
        'pagination'=>array(
            'pageSize'=>10,
        ),
    ));
    // $dataProvider->getData() will return a list of arrays.

关于DataProvider详细文档可以参见 [Yii文档][Yii]

[201212128001]: http://www.imobilebbs.com/wordpress/wp-content/uploads/2012/12/201212128001.png
[201212128001 1]: http://www.imobilebbs.com/wordpress/archives/4058/attachment/201212128001
[CActiveRecord_findAll]: http://www.yiiframework.com/doc/api/1.1/CActiveRecord#findAll
[criteria]: http://www.yiiframework.com/doc/api/1.1/CActiveDataProvider#criteria
[view plain]: http://blog.csdn.net/mapdigit/article/details/8449554#
[rawData]: http://www.yiiframework.com/doc/api/1.1/CArrayDataProvider#rawData
[sql]: http://www.yiiframework.com/doc/api/1.1/CSqlDataProvider#sql
[Yii]: http://www.yiiframework.com/doc/api/1.1/CDataProvider