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opt_exclude_null_key_or_index_entries_.htm
Navigation:  Language Reference > 5 - Declaration Attributes > Variable and Entity Attributes >====== OPT (exclude null KEY or INDEX entries) ====== Previous pageReturn to chapter overviewNext page

OPT

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The OPT attribute (PROP:OPT) excludes entries in the KEY or INDEX for records with “null” values in all fields comprising the KEY or INDEX. For the purpose of this attribute, a “null” value is defined as zero in a numeric field or all blank spaces (20h) in a string field.

Example:

Names   FILE,DRIVER('Clarion'),PRE(Nam)  !Declare a file structure

NameKey  KEY(Nam:Name),OPT         !Declare name key, exclude blanks

NbrKey   KEY(Nam:Number),OPT       !Declare number key, exclude zeroes

Rec      RECORD

Name      STRING(20)

Number    SHORT

        END

       END

See Also:

INDEX

KEY

opt_exclude_null_key_or_index_entries_.htm.txt · Last modified: 2021/04/15 15:57 (external edit)