|
|
| (6 intermediate revisions by 3 users not shown) |
| Line 1: |
Line 1: |
| {{Hierarchy header}}
| | Content moved to m204int page of same name, but history preserved here. |
| The following sections contain new or changed features in [[Fast/Reload]].
| |
| | |
| ==Warning messages for some DV, STORE-x, and repeatibility changes==
| |
| V7R2 of ''Model 204'' introduced several new field attributes.
| |
| Reorganizing a file and changing some of these attributes may
| |
| create differences in field processing which may not be
| |
| obvious at first glance.
| |
|
| |
| To highlight this, ''Fast/Reload'' will issue a warning
| |
| message (MSIR.1037) for each attribute change that may have some
| |
| of these subtle effects.
| |
|
| |
| For the most part, applications using the reorganized file
| |
| will continue to work as before.
| |
|
| |
| One source of possible change in application behavior
| |
| involves use of the following User Language constructs:
| |
| <ul>
| |
| <li>the <tt>Is Present</tt> test
| |
| <li>the count returned by a <tt>Count Occurrences Of</tt> statement
| |
| <li>the number of iterations of a <tt>For Each Occurrence Of</tt> loop
| |
| </ul>
| |
| All three of the above constructs have equivalent exposure to the
| |
| changes in field attributes, even though the examples below only use
| |
| <tt>Is Present</tt>, for brevity.
| |
|
| |
| The other source of possible change in behavior is:
| |
| <ul>
| |
| <li>the value returned when referencing a physically absent field
| |
| occurrence which was AT-MOST-ONE prior to the reorganization
| |
| </ul>
| |
| This is shown in the examples using the <tt>Print</tt> statement,
| |
| although of course the change could be in any kind of reference to the
| |
| field value.
| |
|
| |
| When changing field attributes as part of reorganizing a file,
| |
| you should understand the
| |
| impact of the change; to help in this,
| |
| the conditions that cause warning messages are listed in the following
| |
| subsections,
| |
| along with a very brief example of a possible change in behavior.
| |
|
| |
| '''Notes:'''
| |
| <ul>
| |
| <li>Other changes in these field attributes do not cause the kinds of
| |
| problems discussed here.
| |
| For example, you can change the DEFAULT-VALUE, STORE-DEFAULT, and
| |
| STORE-NONE attributes of an EXACTLY-ONE field without any consequences
| |
| about User Language application behavior.
| |
| <li>Although the examples below all involve fields defined within
| |
| fieldgroups, the potential problems, and the warning messages issued
| |
| by ''Fast/Reload'', apply equally to fields defined outside fieldgroups.
| |
| </ul>
| |
|
| |
| In these examples, assume you are reorganizing with UAI/LAI a
| |
| file with the following “old” definitions:
| |
| <pre>
| |
| DEFINE FIELD KEY WITH ORDERED
| |
| DEFINE FIELDGROUP GRP
| |
| DEFINE FIELD EXO.OLD (FG GRP)
| |
| DEFINE FIELD REPT.OLD.MISS (REPT FG GRP)
| |
| DEFINE FIELD REPT.OLD.XX (REPT FG GRP)
| |
| DEFINE FIELD REPT.OLD.NUL (REPT FG GRP)
| |
| DEFINE FIELD AMO.OLD.DF_YY (ONE DV 'YY' FG GRP)
| |
| DEFINE FIELD AMO.OLD.SD_LIT (ONE DV 'AA' SD LIT FG GRP)
| |
| </pre>
| |
| And assume that a record has been stored as follows:
| |
| <pre>
| |
| Store Record
| |
| KEY = 'Some unique value'
| |
| Then Continue
| |
| Add Fieldgroup GRP
| |
| REPT.OLD.XX = 'xx'
| |
| REPT.OLD.NUL = ''
| |
| AMO.OLD.SD_LIT = 'AA'
| |
| End Add
| |
| End Store
| |
| </pre>
| |
| Each example contains a field definition, used in the LAI step,
| |
| to highlight one condition, and contains a User Language fragment which
| |
| is assumed to be contained within the following:
| |
| <pre>
| |
| FR Where KEY = 'Some unique value'
| |
| For Fieldgroup GRP
| |
| ... example fragment
| |
| End For
| |
| End For
| |
| </pre>
| |
|
| |
| The conditions are shown in the following subsections.
| |
| ===EXONE -> non-EXONE with STORE-x NONE===
| |
| Case: Changing a field that was EXACTLY-ONE in the UAI to AT-MOST-ONE or
| |
| REPEATABLE, with either STORE-DEFAULT NONE or STORE-NULL NONE.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD EXO.OLD (REPT SN NONE FG GRP)
| |
| </pre>
| |
| | |
| User Language fragment:
| |
| <pre>
| |
| If EXO.OLD Is Present Then Print 'Present'
| |
| Else Print 'Not Present'; End If
| |
| </pre>
| |
| | |
| Result prior to reorg:
| |
| <pre>
| |
| Present
| |
| </pre>
| |
| | |
| Result after reorg:
| |
| <pre>
| |
| Not Present
| |
| </pre>
| |
| ===REPT -> EXONE===
| |
| Case: Changing a field that was REPEATABLE in the UAI to EXACTLY-ONE.
| |
|
| |
| There is one exception to this, which does not produce a warning:
| |
| if the field was not a member of a
| |
| fieldgroup in the UAI, and is a member of a fielgroup in the LAI.
| |
| Note that the "out of synch" check of this "collecting
| |
| loose fields" LAI feature ensures there is no exposure
| |
| to a change in User Language behavior when using such a field.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD REPT.OLD.MISS (EXONE FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| If REPT.OLD.MISS Is Present Then Print 'Present'
| |
| Else Print 'Not Present'; End If
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| Not Present
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| Present
| |
| </pre>
| |
| | |
| ===REPT -> ONE STORE-x NONE===
| |
| Case: Changing a field that was REPEATABLE in the UAI to EXACTLY-ONE.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD REPT.OLD.XX (ONE DV 'xx' SD NONE FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| If REPT.OLD.XX Is Present Then Print 'Present'
| |
| Else Print 'Not Present'; End If
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| Present
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| Not Present
| |
| </pre>
| |
| ===ONE -> ONE with changed DV===
| |
| Case: Changing a field that was AT-MOST-ONE in the UAI to a different DEFAULT-VALUE in the LAI.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD AMO.OLD.DF_YY (ONE DV 'ZZ' FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| Print AMO.OLD.DF_YY
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| YY
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| ZZ
| |
| </pre>
| |
| | |
| ===ONE -> EXONE===
| |
| Case: Changing a field that was AT-MOST-ONE in the UAI to EXACTLY-ONE in the LAI.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD AMO.OLD.DF_YY (EXONE FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| If AMO.OLD.DF_YY Is Present Then Print 'Present'
| |
| Else Print 'Not Present'; End If
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| Not Present
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| Present
| |
| </pre>
| |
| ===ONE with DV -> REPT===
| |
| Case: Changing a field that was AT-MOST-ONE with DEFAULT-VALUE in the UAI to REPEATABLE in the LAI.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD AMO.OLD.DF_YY (REPT FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| Print '>' With AMO.OLD.DF_YY With '<'
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| >YY<
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| ><
| |
| </pre>
| |
| ===ONE SD LIT/ALL -> SD NONE===
| |
| Case: Changing a field that was AT-MOST-ONE with STORE-DEFAULT LIT or ALL in
| |
| the UAI to STORE-DEFAULT NONE in the LAI.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD AMO.OLD.SD_LIT (ONE DV 'AA' SD NONE FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| If AMO.OLD.SD_LIT Is Present Then Print 'Present'
| |
| Else Print 'Not Present'; End If
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| Present
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| Not present
| |
| </pre>
| |
| ===Non-EXONE SN LIT/ALL -> SN NONE===
| |
| Case: Changing a field that was AT-MOST-ONE or REPEATABLE, with STORE-NULL
| |
| LIT or ALL, in the UAI to STORE-NULL NONE in the LAI.
| |
|
| |
| There is one exception to this, which does not produce a warning:
| |
| if the field was not a member of a
| |
| fieldgroup in the UAI, and it is a member of a fielgroup in the LAI.
| |
| Note that the "out of synch" check of this "collecting
| |
| loose fields" LAI feature ensures there is no exposure
| |
| to a change in User Language behavior when using such a field.
| |
|
| |
| Changed definition in LAI:
| |
| <pre>
| |
| DEFINE FIELD REPT.OLD.NUL (REPT SN NONE FG GRP)
| |
| </pre>
| |
|
| |
| User Language fragment:
| |
| <pre>
| |
| If REPT.OLD.NUL Is Present Then Print 'Present'
| |
| Else Print 'Not Present'; End If
| |
| </pre>
| |
|
| |
| Result prior to reorg:
| |
| <pre>
| |
| Present
| |
| </pre>
| |
|
| |
| Result after reorg:
| |
| <pre>
| |
| Not Present
| |
| </pre>
| |
| | |
| {{Hierarchy footer}}
| |