# SimpleDataSet

The data set element represents a result set retrieved from an external data provider.

### Description

The Data Set element is an abstract element that includes data-access and report-related properties and other content common to all kinds of data sets.

Its script methods execute as methods of a JavaScript object that represents the data set. See the Data Scripting Objects section for a description of the `DataSet` scripting object.

### Inherited Properties

name
  The name is required to identify a data set.

### See Also

`DataSet scripting object`

## paramBindings

A list of data set parameter binding elements that bind data set input parameters to BIRT expressions.

### Description

A list of data set parameter binding elements that bind data set input parameters to BIRT expressions. Each ParamBinding structure associates a parameter name with an expression.

BIRT differentiates between data set parameters and report parameters. Data set input parameters are not automatically exposed as report parameters. However, the report developer can define report parameters that match data set input parameters. In this case, data set input parameter binding associates data set input parameters with the values of report parameters.

The Data Set element provides a list of parameter binding elements that bind a value to each query parameter.

The bind expression frequently includes a reference to a report parameter, configuration variable, or a row in an outer query. However, the expression can include any valid JavaScript expression.

### See Also

`ParamBinding structure`

Report Item `paramBindings` property

## cachedRowCount

Number of rows that will be cached when the data rows are retrived from DB.

### Description

Number of rows that will be cached when the data rows are first time retrieved from DB, the cached data will be used after that unless user choose to flush the cache. This will speed up the report developing.

## dataSource

The database connection that the data set is used.

### Description

Name of the data source, that is the database connection this data set is using.

## refTemplateParameter

Name of the template parameter definition.

### Description

when a data set is created from an template data set, this property will reference to the base data set.

## beforeOpen

Called just before BIRT opens the data set. Allows the application to customize the data set properties.

### Description

Called just before BIRT opens the data set. Allows the application to customize the data set properties.

### See Also

`afterOpen` method

## afterOpen

Called just after BIRT opens the data set. Allows the application to perform any code-based initialization required for the data set.

### Description

Called just after BIRT opens the data set. Allows the application to perform any code-based initialization required for the data set.

### See Also

`beforeOpen` method

## onFetch

Called just after fetching each row before applying filters or calculating computed columns.

### Description

Called just after fetching each row before applying filters or calculating computed columns.

### See Also

`DataRow` scripting object

## beforeClose

Called just before BIRT closes the data set. Allows the application to perform code-based cleanup.

### Description

Called just before BIRT closes the data set. Allows the application to perform code-based cleanup.

### See Also

`afterClose` method

## afterClose

Called just after BIRT closes the data set. Allows the application to perform code-based cleanup.

### Description

Called just after BIRT closes the data set. Allows the application to perform code-based cleanup.

### See Also

`beforeClose` method