HP 3000 Manuals HP 3000 Manuals
CREATE RELATIONSHIP
Creates a new relationship.
Syntax
C[REATE] R[ELATIONSHIP] entity-name1
,entity-name2
[,entity-name3]
[,entity-name4]
[,entity-name5]
[,entity-name6]
;R[ELATIONSHIP-]T[YPE] = entity-type-name1
,entity-type-name2
[,entity-type-name3]
[,entity-type-name4]
[,entity-type-name5]
[,entity-type-name6]
[;R[ELATIONSHIP-]C[LASS] = relation-class-name]
[;A[TTRIBUTE-]L[IST]=([ attribute-name1=[attribute-value1]]
[,attribute-name2=[attribute-value2]]
.
.
.
[,attribute-nameN=[attribute-valueN]])]
[;C[OMMON] = common-entity-name1
,common-entity-name2
[,common-entity-name3]
[,common-entity-name4]
[,common-entity-name5]
[,common-entity-name6]]
.
Parameters
entity-name(N) Name of the entity that establishes a relationship.
You can specify up to six entity names. The order
of the entities entered should correspond to the
order of the entity types in the relationship type.
entity-type-name(N) Name of the entity type involved in the
relationship type.
relation-class-name Name of the relationship class.
attribute-name(N) Name of the attribute to be assigned a value.
attribute-value(N) The value to be assigned to the attribute. If the
attribute is a variable length attribute, you must
specify the value within quotes. Also, if the
attribute is of type alias or character, and the
attribute value includes invalid characters (See
"User-Defined Names" in Chapter 3) or is greater
than 32 characters in length, you must specify the
value within quotes.
common-entity- Name of the entity involved in the relationship in
name(N) the common domain whose attributes are to be shared
by the local domain relationship being created.
This keyword is not allowed if the dictionary is
open in the common domain. If you use this
parameter, the attribute list can contain only the
following attributes:
sensitivity Specifies the access rights to the
entity
relationship The logical order of a child entity
position (the second entity in the
relationship) relative to all other
child entities for the same parent
entity of the same relationship type
If you specify attributes other than these in the
attribute list, then you must not use this
parameter.
Description
System Dictionary automatically assigns values for the following
attributes:
scope-owner
date-created
date-changed
scope-changed
If you do not specify the attribute name or you specify the name, but do
not assign a value, the default value from the attribute's edit values is
used. If the attribute does not have any edit values, then the System
Dictionary default value for the attribute's data type is used.
alias : No alias is assigned
boolean : false
character : ASCII blank
floating : Floating point zero
integer : Binary zero
variable : No value is assigned
If the attribute is of type boolean, the only values allowed are true and
false (may be abbreviated T and F, respectively).
The valid values for the sensitivity attribute are:
private Only the owner scope is allowed access to the relationship,
unless it assigns access to other scopes by associating
the relationship to the scope by means of the ADD
SCOPE-RELATIONSHIP command. This is the default.
read Any scope with read capability may read the relationship.
The owner scope may, in addition, assign modify access to
other scopes by associating the relationship to the scope
by means of the ADD SCOPE-RELATIONSHIP command.
modify Any scope with read capability may read the relationship.
Any scope with create capability may read and modify the
relationship.
You should only specify the attribute sensitivity for the first version
of a relationship to be created. If you do not specify sensitivity for
the first version of a relationship, it defaults to private. If you
specify sensitivity for subsequent versions of a relationship, it is
ignored. If the relationship is to be linked to a relationship in the
common domain, the sensitivity cannot be greater than the sensitivity of
the relationship in the common domain.
The relationship-position attribute is treated specially by the system.
The system uses this attribute as a sequencing number to order
relationships with the same parent entity (i.e. to represent the order
of elements in a record). Accordingly, two relationships of a type with
the same entity in the first position cannot have the same value for
relationship-position. To avoid conflicts, if you omit either
relationship-position completely or do not specify a value, the system
assigns a relationship-position value to place the new relationship at
the end of the current list. That is, the system assigns a value greater
than the largest currently assigned to a relationship with the same
parent entity. Note that this is different from other default values as
the default depends on the values assigned to other relationships and is
different for each relationship.
To link the relationship to a relationship in the common domain, the
current version must be linked to a version in the common domain.
If you assign the relationship an alias, the alias is associated with the
second entity in the relationship. Only the second entity in the
relationship may have an alias, regardless of how many entities form the
relationship. Therefore, relationship aliases are typically useful only
with binary relationships.
Open Mode: Shared-update or exclusive-update
Scope: DA scope or any scope with create capability. The scope
with which the dictionary is open is the owner of the
relationship.
Example
The following example creates a new relationship ORDERS contains CUSTOMER
of relationship type IMAGE-DATABASE contains IMAGE-DATASET. It is linked
to the relationship SALES contains SHIP-TO (of the same type) in the
common domain.
>CREATE RELATIONSHIP orders, customer;
>>RELATIONSHIP-TYPE = image-database,image-dataset;
>>RELATIONSHIP-CLASS = contains;
>>COMMON = sales, ship-to.
>