• Selection condition
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Stored procedures
Runs a view that was created beforehand (can be used to refresh the view data for example). If the view was created by <Source>.CreateView with the hViewPostponed constant, <Source>.ExecuteView must be used to run the view.
Reminder: a view corresponds to the image of a data file at a given time. A view is stored in memory, which insulates it from the modifications performed in the associated data file. A view can be handled like a standard HFSQL data file.
// Runs the Customer34 view
<Result> = <Source>.ExecuteView([<Selection condition>])
<Result>: Boolean
  • True if the view was run,
  • False otherwise. HError returns more details about the problem.
<Source>: Type of Source
Name of view to run. This name was defined by <Source>.CreateView.
<Selection condition>: Optional character string
  • New selection condition for the view records (<Selection Condition> replaces the condition specified when creating the view). This selection condition can be an Ansi or Unicode character string.
  • Empty string ("") to avoid modifying the selection condition.

Selection condition

The general syntax of a condition has the following format:
"CustName>'Smith' and ZipCode=34 or ZipCode=32"
The supported operators depend on the type of items used in the condition:
<>Not equal toValid for all types
>Greater thanValid for all types
>=Greater than or equal toValid for all types
<Less thanValid for all types
<=Less than or equal toValid for all types
=Strictly equal toValid for all types
~=Almost equal toValid for string types only
]ContainsValid for string types only
]=Starts withValid for string types only

Notes about the selection condition:
  • Constant strings must be enclosed in single quotes.
  • If an item name is used in the selection condition, it must only contain letters, numbers and underscore characters ("_"). If the item name contains other characters (apostrophe, etc.), the name of the item must be enclosed in double quotes.
    For example: "e_mail@"]'com'
  • Comparisons between strings are performed according to the ASCII value of the characters and not according to the lexicographic value ('a' > 'Z').
  • The binary memos, the composite keys and the subscripted items cannot be part of a selection condition.
  • If a <string constant> contains single quotes (or double quotes), they must be preceded by a backslash (\).
  • All the items of the main data file can be included in the condition (even the ones that are not items of the view).
  • The condition is applied to each virtual record before it is included in the view. Therefore, you cannot specify several mutually excluding conditions for the same record (join). For example:
    • "Date='1997' and Date='1996'" returns no result.
    • "Date>='1996' and Date<='1997'" returns all the records found between 1996 and 1997.
  • This selection condition can be an Ansi or Unicode character string.
Component: wd270hf.dll
Minimum version required
  • Version 25
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