If we needed to condition the output depending on whether the user is authorized to view this information or not, we could add the following condition:

EmployeeCollection {              EmployeeItem              Where &UsrAut="S"               {                         Id = EmployeeId                         Name = EmployeeDsc                         Address = EmployeeAddress               } }

In this case, the filter is added to the generated SQL sentence, which would be as follows:

SELECT [EmployeeId], [EmployeeDsc], [EmployeeAddress] FROM [Employee] WITH (NOLOCK)  WHERE @AV1UsrAut = "S" ORDER BY  [EmployeeId]

If I wanted to always return this data but display the address to authorized users only, I could write the following: 

EmployeeCollection  {            EmployeeItem           {                   EmployeeId                   EmployeeDsc                   EmployeeAddress [NoOutput]                   Where &UsrAut="S"                   {                             EmployeeAddress = EmployeeAddress;                             EmployeeSalary = EmployeeSalary;                    }            } }

 
In this case, a select sentence is generated without the filter condition, which is transformed into an IF in the DP source:
 

Select a ejecutar: SELECT [EmployeeId], [EmployeeDsc], [EmployeeAddress], [EmployeeSalary]  FROM [Employee] WITH (NOLOCK)  ORDER BY [EmployeeId] Y además en el fuente del DP: if ( AV1UsrAut = "S") { Gxm1employee.gxTpr_Employeeaddress = A363Employee ; Gxm1employee.gxTpr_Employeesalary = A364Employee ; }

Note: If, instead of a group of attributes (Address, Salary, etc.), we want to filter only one value we can write:
EmployeeAddress = EmployeeAddress if &UsrAut="S"; 

Let's see another interesting example:

Let's suppose that we have an application that handles Clients and Prospects (Clients are in one table and Prospects are in another). We want to write a Data Provider that will return a Collection containing the Active Clients or Prospects. 

The Data Provider will receive as parameter the order of whether to display Clients or Prospects.

Below is one way to write it:

Parm(&FiltrarPor)     SDTCliProsCollection {           SDTCliProsCollectionItem using DSClientesActivos()           where &FiltrarPor = 'CLIENTE'           {                    PartnerId = ClienteId                    PartnerName = ClienteName           }           SDTCliProsCollectionItem using DSProspectsActivos()           where &FiltrarPor = 'PROSPECT'           {                    PartnerId = ProspectId                    PartnerName = ProspectName           } }

DSClientesActivos defines the filter over Clients and DSProspectsActivos does the same in the Prospects table.

Note that this will always execute the two select clauses but will add to the where clause the &FilterBy value received by parameter in the Data Provider (therefore, one of them will return data and the other will not).

This generates the following:

SELECT [ClienteTipo], [ClienteId], [ClienteNombre] FROM [Cliente] WITH (NOLOCK)  WHERE (@AV4Filtrar = 'CLIENTE') AND  ([ClienteStatus] = "Activo") ORDER BY [ClienteId] SELECT [ProspectTipo], [ProspectId], [ProspectNombre] FROM [Prospect] WITH (NOLOCK)  WHERE (@AV4Filtrar = 'PROSPECT') AND  ([ProspectStatus] = "Activo") ORDER BY [ProspectId]

However, we can write the Data Provider as shown below, so that it doesn't always execute the two select clauses, but only the corresponding one according to the  &FiltrarPor parameter (the select to be executed is chosen in the generated source).

SDTCliProsCollection {           SDTCliProsCollectionDummy [NoOutput]           where &FiltrarPor = 'CLIENTE'           {                    SDTCliProsCollectionItem using DSClientesActivos()                    {                              PartnerId = ClienteId                              PartnerName = ClienteNombre                    }           }           SDTCliProsCollectionDummy [NoOutput]           where &FiltrarPor = 'PROSPECT'           {                    SDTCliProsCollectionItem using DSProspectActivos()                    {                              PartnerId = ProspectId                              PartnerName = ProspectNombre                    }           } } Select clause to execute in the event that the DP is invoked with &FiltrarPor = 'CLIENTE':   SELECT [ClienteTipo], [ClienteId], [ClienteNombre] FROM [Cliente] WITH (NOLOCK)  WHERE [ClienteStatus] = "Activo" ORDER BY [ClienteId]   Also, in the Data Provider source:          if ( ( String.CompareOrdinal(AV4Filtrar.TrimEnd(' '), "CLIENTE".TrimEnd(' ') ) == 0 ) )          {             AV10DSClie = AV2Cliente ;             /* Using cursor P001R2 */             pr_default.execute(0, new Object[] {AV10DSClie});             while ( (pr_default.getStatus(0) != 101) )             {                ………………………. (select con filtro por [ClienteStatus] = "Activo")             }             pr_default.close(0);          }          if ( ( String.CompareOrdinal(AV4Filtrar.TrimEnd(' '), "PROSPECT".TrimEnd(' ') ) == 0 ) )          {             AV12DSPros = AV3Prospec ;             /* Using cursor P001R3 */             pr_default.execute(1, new Object[] {AV12DSPros});             while ( (pr_default.getStatus(1) != 101) )             {                ……………………….(select con filtro por [ProspectStatus] = "Activo")             }             pr_default.close(1);          }            this.cleanup();