4-2 Oracle Fusion Middleware PLSQL Web Toolkit Reference
type point is table of varchar232767 index by binary_integer. Table 4–2
describes the properties of the owa_image.point data type.
4.4 owa_image.get_x function
This function returns the X coordinate of the point where the user clicked on an image map.
Table 4–3 describes the properties of the owa_image.get_x function.
4.5 owa_image.get_y function
This function returns the Y coordinate of the point where the user clicked on an image map.
Table 4–4 describes the properties of the owa_image.get_y function.
Table 4–2 owa_image.point data type
Properties Definitions
Syntax: point - data type
Returns: Not applicable.
Table 4–3 owa_image.get_x function
Properties Definitions
Syntax: owa_image.get_xp in point return integer;
Parameter: p - the point where the user clicked.
Returns: The X coordinate as an integer.
Table 4–4 owa_image.get_y function
Properties Definitions
Syntax: owa_image.get_yp in point return integer;
Parameters: p - the point where the user clicked.
Returns: The Y coordinate as an integer.
5
The owa_opt_lock Package 5-1
5
The owa_opt_lock Package
The owa_opt_lock package contains subprograms that impose optimistic locking strategies, so as to prevent lost updates. It checks if the row that the user is interested
in updating has been changed by someone else in the meantime.
The PLSQL Gateway cannot use conventional database locking schemes because HTTP is a stateless protocol. The owa_opt_lock package gives you two ways of
dealing with the lost update problem:
■
The hidden fields method stores the previous values in hidden fields in the HTML page. When the user requests an update, the PLSQL Gateway checks these
values against the current state of the database. The update operation is performed only if the values match. To use this method, call the owa_opt_lock.store_values
procedure.
■
The checksum method stores a checksum rather than the values themselves. To use this method, call the owa_opt_lock.checksum function.
These methods are optimistic. They do not prevent other users from performing updates, but they do reject the current update if an intervening update has occurred.
5.1 Summary
owa_opt_lock.vcArray data type - data type to contain ROWIDs.
