UniBasic Commands Reference - Rocket Software

Note: When you create a select list using the BY.EXP keyword against a multivalued
or multi-subvalued attribute, the resulting select list contains the multivalue position
in the second value of the attribute and the multi-subvalue position in the third value
of the attribute. If a BY.EXP select statement is executed against an attribute with a
value code specifier of MV, the third value in each attribute in the resulting select list
is -5 as the following shows:
001: 785}1}-5
002: 796}1}-5
003: 812}1}-5
...
READNEXT assigns the values and subvalues of each record ID to val.var and
subval.var. The val.var and subval.var each can contain more than one data value
(separated by value or subvalue marks) if you use more than one BY.EXP keyword
when you create the select list. In this case, the first subvalue in val.var and in
subval.var corresponds to the value and subvalue position of the attribute in the first
BY.EXP expression. The second subvalue in val.var and in subval.var corresponds
to the value and subvalue position of the attribute in the second BY.EXP clause, and
so forth for each successive BY.EXP clause.
Parameters
The following table describes each parameter of the syntax.
Parameter Description
id.var Specifies a variable to contain the value of the next record ID.
,val.var,subval.var Specifies a value and subvalue to read.
FROM list.num.expr Specifies which select list (0-9) you want to use. If you do not
specify list.num, the default (0) list is used. If no items are
available in the list, UniData executes the ELSE clause.
READNEXT Parameters
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