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