将 Apps 与 Data Service 结合使用

背景信息

备注：

• A maximum of 1000 records for any filter are retrieved at runtime.
• After the entity data is loaded, the data is refreshed only when a rule is executed. Any changes made to the entity via processes, or other means, do not automatically update in Apps. Make sure to explicitly refresh the data in these scenarios.
• The in operator only supports primitive data types, such as: string, number, boolean, null.

使用choice-set的 Data Service 方案中不支持in运算符。您可以改为使用contains运算符，但只能用于一个输入。

概述

在开始本示例之前，请确保您具有 Data Service 的适当权限。如需了解详情，请查看“Data Service - 管理访问权限”页面。

For the purpose of this example, we will use an entity called Customer with the following fields:

• Address
• 地址 2
• 城市
• 电子邮件
• 名称
• 电话
• 计划
• 状态
• 邮政编码

按状态筛选客户

Use the Function: Fetch function to retrieve multiple entity records. Additionally, use the Query builder to filter the retrieved records. In this example, we apply a filter to the Customer entity, so the search only returns customers from the state of Washington.

Refer to The Fetch function for more details.

备注：

If you want to retrieve a single record, use the FetchOne function instead.

1. Open an existing application, or create a new one.
2. Add a Table control to your app:
   1. 选择“添加控件”。
   2. Select Display.
   3. Drag the Table control to an area in your app.
3. Add an entity to your app:
   1. Select the Add any icon from the top of the canvas.
   2. 选择实体。
   3. Select a tenant.
   4. Select the entity you want to add to your app, then Add.
4. Bind the entity to the Table control:
   1. In the General tab of the Properties panel, select the Additional resources button adjacent to Data source.
   2. Select Query builder.
   3. Select the entity you want to use, then Add condition.
   4. Select a field from the dropdown menu, then an operator, such as =.
   5. Enter the string by which you want to filter the records, surrounded by quotation marks.
      For example, if you only want customer records from the state of Washington, add "WA" as a value.
5. Use the Expression editor to apply a filter under specific conditions:
   1. In the Query builder, select the Open resources button, then Expression editor.
   2. Write an expression containing a condition. For example, you can use an IF condition to only apply a filter when a Dropdown control on the main page of the app is not blank and contains a user-specified value:

      Fetch(of Customer)(  
      If(  
      MainPage.Dropdown is Nothing,  
      Nothing,  
      createFilterGroup(New QueryFilter(){addFilter("State", "contains", MainPage.Dropdown.Value)}, Nothing, 0)),  
      Nothing, Nothing, Nothing, New ExpansionFieldOption( {addExpansionFieldOption("CreatedBy", New String(){"Id","Name"}), addExpansionFieldOption("UpdatedBy", New String(){"Id","Name"})})

When you preview or run the app, the query executes and retrieves the filtered records.

对客户排序

Use the Query builder to apply sorting options to your search.

1. Open an existing application, or create a new one.
2. Add a Table control to your app:
   1. 选择“添加控件”。
   2. Select Display.
   3. Drag the Table control to an area in your app.
3. Add an entity to your app:
   1. Select the Add any icon from the top of the canvas.
   2. 选择实体。
   3. Select a tenant.
   4. Select the entity you want to add to your app, then Add.
4. Bind the entity to the Table and apply a sorting rule:
   1. In the General tab of the Properties panel, select the Additional resources button adjacent to Data source.
   2. Select Query builder.
   3. Select Additional settings.
   4. In the Sort by field, add the field by which you want to sort, such as Name.
   5. The Sort ascending field is set to true by default. Select the field, then enter False to sort the results in descending order.
5. Preview or run your app.

   When you preview or run your app, the Table displays records from the Name field in your entity, in alphabetically descending order.

Using entities with Edit Grid

You can use the Edit Grid control to display entity records in your app, and perform CRUD operations on your entity using this control.

Refer to Using Fetch to retrieve entity records in Edit Grid controls and Using entities with Edit Grid controls for more details and practical examples related to the Edit Grid control.