Defining a Conceptual Property - the General Tab

 

 

Data displayed

Assigned to the entity/subtype entity/relationship

Name of the conceptual entity, of the subtype entity or of the relationship to which the property is assigned.

This field is not visible if the property is not assigned to an object.

 

Data entry

Name

Name of the property.

This name must be a valid property name (as defined by IBM), unique among the names of properties in the environment.

Length: 15 characters maximum.

Mandatory entry.

 

Description

Description clearly identifying the property.

Length: 50 characters maximum.

Mandatory entry.

 

Data type

Possible reference data type of the property.

The list of available data types varies according to the visibility of the property and to the location where the dialog box was opened: from or outside of an application area. In some cases, only public data types will be displayed, and in other cases, the private types of the current application area will also be displayed.

If a data type is selected, these data items (length, number of decimals) are reproduced, if they exist, to the property and, thus, are protected.

Default: None.

 

Type

Values available:

Default: Alphanumeric.

 

Note: The Date, Time and Timestamp types are not supported by the C generator for ADELIA programs.

 

With Alphanumerical types, you can specify that the field must be stored in the database in Unicode (or a national character set, depending on the DBMS) by checking the Unicode box associated with the field.

 

Length

Number with 7 positions maximum.

The length can be indicated for alphanumeric properties:

- in kilobytes, by adding the suffix "K" to the value (e.g. 100K for 102400), or

- in megabytes, by adding the suffix "M" to the value (e.g. 1M for 1048576).

The length can be either the length of the property, or the length of the property type if this type has a length. In the latter case, the length cannot be modified.

Mandatory entry.

 

For the Date, Time and Timestamp types, the length is protected and automatically assigned as follows:

• Time: 8 characters.
• Timestamp: 26 characters.
• Date:

 

When the type is Alphanumeric, you can check the relevant Variable chekbox to specify the type is variable. An input field then appears, letting you enter a minimum reserved length.

 

Note: By default, for PC SQL DBMSs, alphanumeric types (whether variable or not) are generated in VARCHAR format, except if the "Non variable alphanumerical in CHAR" box is checked. When this is the case, only the variable alpha types are generated in VARCHAR format, the non variable types being generated in CHAR format.

 

When the type is Numerical (condensed, extended or binary) and the number of decimal places is zero, the column can be defined as auto incrementing (value generated automatically by the DBMS) by checking the Auto increment box. This option is only available if the property is assigned to a conceptual entity. It cannot be accessed if the entity already has an auto increment-type column. While not mandatory, it is best for an auto increment-type column to be part of the table's primary key.

The auto increment type can have certain limits depending on the DBMS used. For further information, see topic Data Type Limitations.

 

For the Image type, the length is only taken into account with DB2/400. This length must be a value between 1 and 2048 Mb, or it can be set to the Default value, in which case the table column size will be DB2/400's default size, i.e. 1 Mb.

 

Min. reserved lg.

Minimum reserved length.

This value is only taken into account by DB2/400.

This field is only visible if the type indicated in the Type field is Alphanumeric and the Variable checkbox is checked.

 

Date format

Format used for the date:

Default: *ISO.

This field is only visible when Date is specified in the Type field.

 

Nbr of decimals

Number of two-digit decimal positions.

This can be either the number of decimal positions of the property, or the number of decimal positions of the type, if the property has a type. In the latter case, it cannot be modified.

As a rule, if this field is left blank, the number of decimals will be equal to 0.

This field is only visible if the type specified in the Type field is Binary, Packed, Packed by def. or Extended.

Optional entry.

 

Key

Sequence number of the property in the key when the property is part of the key (Key field not empty and different from 0).

This field is only visible if the property is assigned to a conceptual entity.

This field is protected when the conceptual property is dummy (in this case, it cannot be the key).

Length: 2 characters maximum.

Optional entry.

 

Short name

This name must be a valid short name (as defined by IBM), unique among the conceptual properties' short names of a same environment.

Length: 10 characters maximum.

Optional entry.

 

Radio buttons

Visibility

The visibility of a property can be either public or private.

Only the owner of the property, or a software engineer with modification authorities, can change the visibility.

A public property cannot be changed into a private property if it is attached to more than one application area.

If the property is a key of a public entity, it is necessarily public and cannot become private. If the property has a private data type, it is necessarily private and cannot become public.

In creation mode, the visibility is by default set to public.

 

Buttons

Display/Assign

This button opens a dialog box displaying the list of management rules assigned to the property, as well as the list of available management rules which can be assigned to the property.

 

Sequence

This button opens a dialog box displaying the list of management rules assigned to the property, in order to resequence this list by modifying the sequence numbers of the listed management rules.

This button is not active in display mode.

 

Appl. areas

This button opens a dialog box which is used to display the various application areas to which the property is attached.

 

Information

This button opens a dialog box displaying information on the current property, such as the name of the software engineer-owner, the dates and times of creation and modification.

 

Comments

This button opens a dialog box for entering a comment text which will be associated with the current property.

 

 

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