E@DBLOCKNXTRNG

Name

The E@DBLOCKNXTRNG call has the following format:

DN@<Logical>(E@DBLOCKNXTRNG)

where <Logical> identifies the database file to use to perform the E@DBLOCKNXTRNG call.

Description

When you need to update a range of data without interruption, E@DBLOCKNXTRNG retrieves the next database record in a range and prepares it for updating by an E@DBSTORE call.

Using the API in a Program

You must precede E@DBLOCKNXTRNG with E@DBLOCKBEGRNG, E@DBLOCKSUBRNG, E@DBLOCKMIDRNG, or E@DBLOCKMIDSUB.

Input Values


Field	Description
<Logical>	You must specify the database index name that you want to create a record in.
Record retrieval variables (also known as D@ fields)	You must populate the index key fields used to locate the record before using this call. Fill in only the D@ fields that define the appropriate range; leave empty those D@ fields that do not define the range.
E@DBBEGRNG	Move a number into E@DBBEGRNG in order to tell the interface which key is the last significant one defining the range. This number is equivalent to the position of the field in the index.

Return Values


Field	Description
D<prefix>@NOTFOUND – or – E@KEY@FOUND	The Modify routines set D<prefix>@NOTFOUND to FALSE if a record is found, TRUE if a record is not found, or E@KEY@FOUND if the keys are found.

Programming Example

The following example shows how to update a series of records in a file.

`EVAL D@CMPNY = PWS#CMPNY EVAL D@DBBEBRNG = 1 CALLP DN@DBHRSAW1(E@DBLOCKNXTRNG) DOW DSAW@NOTFOUND = FALSE EVAL DSAWCMMRT = PWS#NWCMMRT CALLP DSAW@IO(E@DBSTORE) DBHRSAW CALLP DN@DBHRSAW1(E@DBLOCKNXTRNG)`

     EVAL      D@CMPNY        = PWS#CMPNY
     EVAL      D@DBBEBRNG     = 1                       
     CALLP     DN@DBHRSAW1(E@DBLOCKNXTRNG)              
     DOW       DSAW@NOTFOUND = FALSE                       
     EVAL      DSAWCMMRT     = PWS#NWCMMRT
     CALLP     DSAW@IO(E@DBSTORE)                    DBHRSAW
     CALLP     DN@DBHRSAW1(E@DBLOCKNXTRNG)

Comparing this example to the routine that uses E@DBLOCKGE and E@DBLOCKNXT shows two major usage differences:

You do not have to fill the extra index key with blanks. Instead, the E@DBBEGRNG variable identifies the last key to be used as a delimiter.
You no longer need to use the extra OR check on the D@field in the DOW clause. The interface performs the check.

You can also use a E@DBKFNDBEGRNG, E@DBFINDSUBRNG and E@DBFINDPRVRNG loop for updates with an E@DBLOCKEQ. If your use the find loop versus a modify loop, the E@DBLOCKEQ must be a different index than that used on the FIND loop.