OpenEdge Data Management: DataServer for Microsoft SQL Server

Initial Programming Considerations
2–54
RECID values can be stored in an INTEGER data type. The internal bit size for the INTEGER data
type is not expanded from 32-bit to a 64-bit field size. If the RECID value stored in the INTEGER
data type does exceed 32 bits however, an overflow condition occurs. See the “Overflow
checking” section on page 2–47.
You can make an existing application that includes RECID behave more consistently across data
sources by replacing RECID with ROWID. See the “ROWID function” section on page 2–52 for
more information.
DEFINE BROWSE statement
The DEFINE BROWSE statement relies on a unique record identifier for forward and backward
scrolling. If your MS SQL Server data source table does not support the OpenEdge ROWID
function (through either a PROGRESS_RECID column or an indexed column with unique values,
defined as bigint in OpenEdge Release 10.1B and later or as integer in Release 10.A or
earlier), you can write code that explicitly requests the default OpenEdge browse scrolling
behavior, similar to this:
DEFINE VARIABLE iRow AS INTEGER NO-UNDO.
DEFINE QUERY q FOR customer FIELDS (custnum name address) SCROLLING NO-LOCK.
DEFINE BROWSE b QUERY q DISPLAY custnum name address WITH 10 DOWN.
DEFINE BUTTON upd.
OPEN QUERY q FOR EACH customer NO-LOCK.
ENABLE upd b WITH FRAME x.
ON CHOOSE OF upd DO:
iRow = CURRENT-RESULT-ROW("q").
GET PREV q.
GET NEXT q EXCLUSIVE-LOCK.
IF CURRENT-RESULT-ROW("q") EQ iRow THEN
UPDATE customer.address WITH FRAME z VIEW-AS DIALOG-BOX.
/* else, indicate that an error occurred: the record was deleted in
the meantime. */
DISPLAY customer.address WITH BROWSE b.
END.
WAIT-FOR WINDOW-CLOSE OF CURRENT-WINDOW.
Field lists
The DataServer fully supports the use of field lists in queries (DEFINE QUERY, FOR EACH,
PRESELECT, and SQL SELECT statements). Using FIELD and EXCEPT clauses can greatly improve
performance for NO-LOCK queries, particularly if the DataServer is a remote configuration where
the query results must be passed over a network. When a field list is used, unneeded data is not
returned. The field list does not guarantee that it will restrict the data to the specified fields. It
can be necessary to return additional fields such as those required to accommodate the values
of a selected index.
For example, the following statement returns the same results for an OpenEdge database and a
MS SQL Server data source:
DEFINE QUERY myquery FOR customer FIELDS (custnum name) SCROLLING.
OPEN QUERY myquery FOR EACH customer NO-LOCK WHERE custnum LT 6
BY customer.name.