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
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.
Remark: From version 19, HFSQL is the new name of HyperFileSQL.
// Runs the Customer34 view
<Result> = <Source>.ExecuteView([<Selection condition>])
- 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.
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:
|<>||Different||Valid for all types|
|>||Greater than||Valid for all types|
|>=||Greater than or equal to||Valid for all types|
|<||Less than||Valid for all types|
|<=||Less than or equal to||Valid for all types|
|=||Strictly equal to||Valid for all types|
|~=||Almost equal to||Valid for string types only|
|]||Contains||Valid for string types only|
|]=||Starts with||Valid 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 an <string constant> contains a single quote (or double quote), this single quote (or double quote) must be preceded by an anti-slash ( \).
- 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.