Defining a Logical Property - the General Tab

Displayed data

Public/Private (visibility)

Property visibility.

If the property is "purely" logical, the visibility is that of the logical entity.

Otherwise, it follows that of its conceptual origin.

Data entry

Name

Name of the logical property.

This name must be a valid logical property name (as defined by IBM), unique among the logical property names of a same logical entity.

Length: 15 characters maximum.

This name cannot be modified if the logical property comes from the LDM generation.

Mandatory entry in creation mode.

Description

Description clearly identifying the logical property.

Length: 250 characters maximum.

If, in the environment's attributes the "Size 50 exceeded warning" option for AS/400 object description has been activated, then the text turns red when the description exceeds 50 characters.

Mandatory entry in creation mode.

Data type

Data type of the logical property.

This field is protected when the logical property is of conceptual origin.

The list box offers, in alphabetical order, all the public data types plus, if the property is private, all the data types attached to the same application area as the property. You can use a filter to restrict what is displayed.

If a data type is selected, its information (length, number of decimals), when it exists, is applied to the property and is then protected.

Default: "None".

Type

Values available:

This field is protected when the logical property comes from the conceptual level. However, when a numeric field features a "Packed by def." type at the conceptual level, the "Packed" value appears in the field at the logical level; you can then convert this type into "Extended".

Note: 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

Length of the logical property, decimal positions included: 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).

This field is protected when it comes from the data type possibly selected, or when the logical property comes from the conceptual level.

Mandatory entry.

For 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 not available if the logical entity is taken from the conceptual level, or 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.

Possible values:

This field is only visible when Date is specified in the Type field. It is protected if the logical property comes from the conceptual level.

Nbr of decimals

Number of decimal positions for a numeric property.

This field is protected when it comes from the data type possibly selected, or when the logical property results from the conceptual level.

This number must be lower than or equal to the length.

Length: two characters maximum.

As a rule, if this field is left blank, the logical property is considered as alphanumeric; otherwise, it is considered as numeric.

This field is only visible if the type specified in the Type field is Binary, Packed 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 protected when the logical entity comes from the conceptual level, or if the logical property is dummy (in this last case, it cannot be the key).

Length: 2 characters maximum.

Short name

This name must be a valid short name (as defined by IBM), unique among the short names of a same logical entity.

Length: 10 characters maximum.

If the property comes from the conceptual level, the default short name is that of the conceptual property (possibly renamed in case of duplicates), prefixed with the first character of the entity name.

Mandatory entry.

Associated field

Name of the layout field.

This name must be a valid associated field name (as defined by IBM).

Length: 10 characters maximum.

Default: short name of the logical property, prefixed with the character "Z".

Guide word

Symbolic name of the property used by the Adelia 4GL.

This name must be unique among the guide words of a same logical entity.

Length: 128 characters maximum. A maximum length is defined in the environment attributes, Miscellaneous tab. When exceeded, an error message is displayed.

If the property comes from the conceptual level, the default guide word is the name of the conceptual property (possibly renamed in case of duplicates), prefixed with the first character of the entity name. Otherwise, the logical property name is used, prefixed with the first character of the entity name.

Mandatory entry.

Assoc. guide word

Symbolic name of the layout field used by the Adelia 4GL.

This name must be a valid associated guide word name (as defined by IBM).

Length: 128 characters maximum.

Default: guide word of the logical property, prefixed with the character "Z".

Note: The following naming convention programs for the property names of the following four fields can be found in the USERLIB.DLL dll. Refer to Associating a specific DLL with an environment.

Renamed short name

Logical property's renamed name, coming from program generation.

Length: 10 characters maximum.

Optional entry.

Note: Two logical properties with different renamed names must also have different guide words.

Alternative SQL name

Lets you enter upper/lower case characters, spaces, special characters. Any characters can be entered, even spaces, at the beginning of the input. Spaces at the end of the name are significant.

Length: 128 characters maximum (according to the limit defined in the DBMS).

When specified, the alternative SQL name replaces the guide word for the PDM generation. (The use of the guide word for the PDM generation is specified in the environment attributes, Miscellaneous tab).

Buttons

Information

This button opens a dialog box displaying information about the current logical 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 logical property.

If the logical property is of conceptual origin, this text cannot be modified.

App. areas

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

Display/Assign

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

Sequence

This button opens a dialog box displaying the list of management rules assigned to the logical 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.

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