Data Definition Language (DDL) Reference Manual (G06.24+)

Definition Attributes
Data Definition Language (DDL) Reference Manual—426798-002
6-18
MUST BE Clause
use symbolic literals only for numeric items. The symbolic literals are shown in
Table 6-4 on page 6-18.
value-name
is the name associated with a value in a level 89 enumeration clause for a field
of type ENUM.
MUST BE Clause Guidelines
The following points are guidelines for using the MUST BE clause:
•
Values specified with a MUST BE clause must be consistent with the data type of
the field.
•
When a constant name is the MUST BE value, the constant value must be
consistent with the type of the data item and with the type of any associated level
88 data item.
•
A MUST BE clause cannot be specified for a group item. A MUST BE clause can
be specified for individual fields within the group, as long as the group does not
have an initial value.
•
If a field described with a MUST BE clause also has a VALUE clause, the initial
value specified in the VALUE clause must satisfy the MUST BE constraints.
•
If a field described with a MUST BE clause also has an UPSHIFT clause, the
MUST BE values must be upshifted.
•
If a field described with a MUST BE clause is of type ENUM, the values in the
clause can only be level 89 enumeration names.
•
You can specify only one MUST BE clause for a field.
•
You cannot specify a MUST BE clause in a field or group definition or description
that includes a REDEFINES clause.
•
You cannot specify a MUST BE clause for SQL DATE, SQL TIME, SQL
DATETIME, or SQL INTERVAL fields.
•
You cannot specify CURRENT, SYSTEM, or SQLNULL as a value for a MUST BE
clause.
Table 6-4. Symbolic Literals
Symbolic Literal Value
LOW-NUMBER The minimum numeric value of the type specified for
this field
HIGH-NUMBER The maximum numeric value of the type specified for
this field