E@DBUPDATE

Name

The E@DBUPDATE call has the following format:

DN@<Logical>(E@DBUPDATE)

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

Description

E@DBUPDATE directly updates a single existing record in a file. It combines the actions of the E@DBLOCKEQ and E@DBSTORE routines into a single call. Use this routine when you already know that a record exists, such as when you have already inquired on or modified a record in a previous call.

Using the API in a Program

The performance advantage derived from this reduction in the number of calls brings with it a pair of requirements.

You must enter a value in all D@ fields before performing the routine, because this routine can update the key fields in the index, just as the E@DBLOCKEQ routine does.

You must populate all record fields, unlike the E@DBLOCKEQ routine. This requirement must be enforced because the E@DBUPDATE routine replaces the entire existing record with the contents of all the record fields, even if one or more of them are empty.

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.

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 the same process as the previous example for the E@DBLOCKEQ routine, but using the E@DBUPDATE call to alter a record. The record has already been retrieved using a Find call.

`CALLP U@AUDITBEGIN Audit Begin IF E@DMSFLAG = 1 RETURN ENDIF EVAL D@CRRNCD = F1@CCCRCD CALLP S1@MVDT Move Data CALLP DN@DBIFCUC1(E@DBUPDATE) DBIFCUC CALLP U@AUDITEND Audit End CALLP S1@MVSC Move To Screen EVAL E@CRTMESSAGE = E@CHGCOMPLETE`


     CALLP     U@AUDITBEGIN                      Audit Begin
     IF        E@DMSFLAG = 1                                
     RETURN                                                 
     ENDIF                                                  
     EVAL      D@CRRNCD       = F1@CCCRCD                   
     CALLP     S1@MVDT                             Move Data
     CALLP     DN@DBIFCUC1(E@DBUPDATE)               DBIFCUC
     CALLP     U@AUDITEND                          Audit End
     CALLP     S1@MVSC                        Move To Screen
     EVAL      E@CRTMESSAGE   = E@CHGCOMPLETE

This example shows the same change being made as in the previous example for the E@DBLOCKEQ call. The major differences are that you only use a single call, and you populate the D@ fields and record fields before calling the E@DBUPDATE routine.

In this case, you must be certain that the S1@MVDT fills all of the record fields. If it does not, any unfilled record fields cause the E@DBUPDATE call to overwrite the corresponding file fields with the initialization values.