Physical data file associated with an alias

Canceling the aliases of one or more data files

Alias and queries

• If the query was created by programming (0), all you have to do is create the alias query with this same function while specifying the alias name.
• If the query was created by the report editor, to create an alias, you must:
  • run the initial query.
  • use <Source>.Alias and specify the query name as well as the alias name.
  • use 0 with the alias query. The alias is initialized.
  For example:
  
  QueryAlias is Data Source
  QRY_Query1.Alias(QueryAlias)
  QueryAlias.ExecuteQuery()
  
  
  Remark: When creating the alias, the initial query must have been run.
  Example:
  
  QueryAlias is Data Source
  IF QRY_Query1.ExecuteQuery() = False THEN
  Error(HError(hErrCurrent))
  ELSE
  QRY_Query1.ReadFirst()
  Trace(QRY_Query1.City)
  QRY_Query1.Alias(QueryAlias)
  IF QueryAlias.ExecuteQuery() = False THEN
  Error(HError(hErrCurrent))
  ELSE
  FOR EACH AliasQuery
  Trace(QueryAlias.City)
  END
  END
  END
  

Handling the alias file and its items

• To avoid the "Unknown identifier" error when using an alias file and its items, it is recommended to use a Data source variable to declare the name of the alias before using <Source>.Alias.
  For example:
  
  Order2018 is Data Source
  Order.Alias(Order2018)
  
  
  Caution: the Extern keyword can be used but it slows down the execution significantly.
• In <Source>.ReadSeek, <Source>.ReadFirst, <Source>.ReadNext, ... the name of the alias item cannot be used directly: the name of the item must be enclosed in quotes.
  For example:
  
  srcAlias.ReadSeekFirst("KeyItem", "Sought Value")
  
• Versions 24 and later
  The name of the data source must not be used in quotation marks, if Automatic naming of data sources is enabled in the project description window.
  New in version 24
  The name of the data source must not be used in quotation marks, if Automatic naming of data sources is enabled in the project description window.
  The name of the data source must not be used in quotation marks, if Automatic naming of data sources is enabled in the project description window.
• In the window or page editor, controls cannot be directly bound to the items of the alias files. You must:
  • assign a value to each control in the code.
  • use the ControlAlias function or the DataBinding property before calling:
    • <Window/Page>.FromFile.
    • <Page>.FromFile.
  Example:
  
  ControlAlias(Control, srcAlias)
  OR
  ControlAlias(GR_ControlGroup, srcAlias)
  OR
  ControlAlias(WIN_Window, srcAlias)
  OR
  EDT_CustomerName.DataBinding = "SrcAlias.CustomerName"
  
• The alias files can be handled by <Source>.ListItem and <Source>.ListKey. The alias files can be re-indexed.
• By default, the password of an alias file is identical to the password of the initial data file. This password can be modified by <Source>.Password. The name of the data file used in this function corresponds to the name of the alias.
• The automatic modification of the data files can be applied to the alias files.
• The locks performed on the data files or on the records are effective between the aliases of the same instance of an application.