Create access to multiple records in a coordinated file not keyed to a prior file?
Article ID: 31131
Updated On:
Products
Issue/Introduction
How can I create access to multiple records in a coordinated file not keyed to a prior file?
Environment
Component: V:BLDR
Cause
Temporary field coordination will only pull one coordinated record for each occurrence of the driving field. In the case where we are driven by the master file root, this means exactly one occurrence.
Resolution
To circumvent this, use an additional dummy cord file with a single record. The structure of this file is hierarchical where the level two segment will occur a fixed number of times, as many as potentially needed to be retrieved per driver record. For example, if there could be 160 occurrences of this cord file per master file record, level 2 must be specified to occur 160 times. Level 2 need only contain the data needed to coordinate to the desired file. If the key is 15 bytes for the sake of this discussion then level 2 would have a single field, 15 bytes which occurs 160 times. Record size is 1 + 160*15)
The actual data record can have a single character, say A, in the first byte. The rest of the record is blank, but the record size must match the file definition. This dummy file is read in a one time request just to get this dummy record/structure into the buffer. Use temp field coordination where the TF and initial value is also in the one time request.
The desired file will be read twice for each key. It will be read the first time using a generic read to get the record and move the key to the dummy structure. When all occurrences for a given key are found, then the cataloged request is complete.
The requests can be cataloged and the requests and definitions captured into a Dataview so this is applicable to VISION:Inform as well.
File Def for dummy cord file
dummy FD
dummy L0 rootkey 01 1 0001C0011
dummy L0 seg2key 02 2 0001C0160
dummy L0 sourcef1 02 2 0001C002
dummy L0 sourcef2 02 2 0001C009
dummy L0 sourcef3 02 2 0001C005
Run Control for LDV and to catalog the requests
RF master M4OLD
RF dummy M4CORD7 dummykey T
RF multfile M4CORD8 R
RF multfile M4CORD9 seg2key 7
ONETIME ER 1(col 48)
ONETIME AA read dummy record one time
ONETIME TFdummykey001C A(init value col 29)
ONETIME PR 7rootkey EQ7rootkey
READMULTER
READMULTAA build generic portion of key
READMULTTFgenkey 011C
READMULTPR R Osourcef1 Tgenkey
READMULTPR R Osourcef2 Tgenkey 0309C
READMULTAA clear last - replace blanks into all occurs of level 2
READMULTPR R C 7seg2key
READMULTAA attempt match to generic, if fails - bail
READMULTPR Tgenkey RE8
READMULTPR FRSTATUS EQCKEQL
READMULTPR NS NEXT REQUEST
READMULTAA if ok, move to first lev2 seg and go to sub to continue
READMULTPR R Tgenkey 7seg2key
READMULTPR R 8sourcef3 7sourcef3
READMULTPR GO SUB GETREST
(56) (69)
GETREST ER S 1
GETREST AA a sequential read following a direct read
GETREST AA keeps the key for comparison
GETREST PR RD8
GETREST PR FRSTATUS EQCEGRP
GETREST PR GS RETURN
GETREST AA if not end of group, then successful - replace and continue
GETREST PR R Tgenkey 7seg2key
GETREST PR R 8sourcef3 7sourcef3
GETREST PR GO REQUEST GETREST
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