Reserved keywords

Chapter 3 DBMS Reference Guide

Reserved keywords

For a domain or a column, standard check fields can indicate minimum, maximum, and default values, as well as a list of values.

In general, if the domain or column data type is a string data type, quotation marks surround these values in the generated script. However, quotation marks are not generated in the following cases:

You define a data type that is not recognized as a string data type by PowerDesigner
Value is surrounded by tilde characters
Value is a reserved keyword defined in the DBMS (for example, NULL)

In addition, if the value is already surrounded by quotation marks additional quotation marks are not generated.

The generation of single- or double-quotation marks depends on the current DBMS.

The DBMS lists reserved keywords as values for the field ReservedDefault, under the category Keywords.

Example

The following example shows the result of a reserved keyword for the DBMS Sybase AS Anywhere 6.

Sybase AS Anywhere 6 DBMS contains the following lines:

ReservedDefault =
NULL
AUTOINCREMENT
CURRENT DATE
CURRENT PUBLISHER
CURRENT TIME
CURRENT TIMESTAMP
CURRENT USER
LAST USER 
USER

You define CURRENT DATE as the default value of a column:

The resulting script contains the string CURRENT DATE without quotation marks.

create table SALE
(
    SALE_ID          T_IDENTIFIER          not null,
    STOR_ID          T_AN_IDENTIFIER       not null,
    TITLE_ISBN       char(12)              not null,
    SALE_DATE        T_DATE                not null
        default CURRENT DATE,
    SALE_AMOUNT      T_AMOUNT                      ,
    SALE_TERMS       T_LONG_TEXT                   ,
    SALE_QTY         T_QUANTITY                    ,
    primary key (SALE_ID)
);

When you run this script, Sybase Adaptive Server Anywhere will recognize CURRENT DATE as a reserved default value.