CursorScroll database parameter
Description
When used with the CursorLock parameter, specifies scrolling
options for cursors in an ODBC data source.
The location of a cursor indicates the current position in
the result set produced by a SQL statement. Scrolling allows
a cursor to move through the data in a result set one row at a time.
Controls
ODBC (if driver and back-end DBMS support this feature)
Syntax
|
1 |
CursorScroll='<span>scroll_value</span>' |
|
Parameter |
Description |
|---|---|
|
scroll_value |
Specifies the type of scrolling you want
|
Default
If you do not specify a value for CursorScroll, PowerBuilder defaults
to the cursor scroll settings specified for your ODBC data source
driver.
Usage
For large result sets, it might be impractical to use a keyset-driven
cursor that requires the driver to save keys for the entire result
set. Instead, you can use a mixed cursor by
specifying a 32-bit integer value that is the number of rows in
your keyset (see Example 2). This number is typically smaller than
the result set. The default keyset size is 0.
A mixed cursor uses KeySet scrolling within the specified
keyset and Dynamic scrolling outside the keyset.
Examples
Example 1
To set scrolling and locking options for cursors in an ODBC
data source:
-
Database
profileSelect Dynamic Scrolling from the Scrolling Options drop-down
list and Optimistic Using Values from the Locking drop-down list
on the Transaction page in the Database Profile Setup dialog box. -
Application
Type the following in code:
1SQLCA.DbParameter="CursorScroll='Dynamic',<br>CursorLock='OptValue'"
Example 2
This example sets the number of rows in the keyset to 100. Assume
that the entire result set has 1000 rows. When the cursor is opened,
the driver saves keys for the first 100 rows of the result set.
It then retrieves the next block of 100 keys until the entire result
set is retrieved.
-
Database
profileType
100in the Scrolling
Options box on the Transaction page in the Database Profile Setup
dialog box. -
Application
Type the following in code:
1SQLCA.DbParameter="CursorScroll=100"