Aggregate
Fetch data using an optimized query.
In Web Applications you can use an Aggregate to fetch data from the server database, while in Mobile Apps you can use an Aggregate to fetch data from the server database or from the local storage.
Properties
| Name | Description | Mandatory | Default value | Observations |
|---|---|---|---|---|
| Name | Identifies an element in the scope where it is defined, like a screen, action, or module. | Yes | ||
| Description | Text that documents the element. | Useful for documentation purpose. The maximum size of this property is 2000 characters. |
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| Timeout | Maximum time in seconds to wait for the Aggregate to return data before triggering a Communication Exception. Overrides the default timeout defined on the module. | If there is no value specified in this property, the timeout corresponds to the "Default query timeout" parameter specified in the Platform Server Configuration Tool. Property not available in client actions. |
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| Cache in Minutes | Maximum time content or results are stored in memory. When undefined, nothing is cached. | Property not available in client actions. | ||
| Max. Records | Maximum number of records read from the database. | If undefined, the default value is: – In widgets: StartIndex + LineCount + 1; – Exporting to Excel: No limit. |
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| Start Index | Index of the first List item to iterate. Can be an expression. | The expression used in this property (if present) is evaluated before the web screen preparation. | ||
| Fetch | Yes | At start | ||
| Events | ||||
| On After Fetch | Action executed after the aggregate fetches data from the data source. | |||
Runtime Properties
| Name | Description | Read Only | Type | Observations |
|---|---|---|---|---|
| List | Collection of records returned by the performed query. | Record List | ||
| Count | Number of records returned by the Count query. | Long Integer | ||
| IsDataFetched | True when data has been fetched from the database and is ready to be used. | Yes | Boolean | |
| HasFetchError | True when there is an error during data fetch due to a server error or communication timeout. | Yes | Boolean |