Using Caché Objects - InterSystems Documentation

• ODBC — The format in which data can be presented via ODBC or JDBC. This format
is used when data is exposed to ODBC/SQL. The available formats correspond to those
defined by ODBC.
If a property uses a system data type (or a data type derived from a system data type), the
property automatically includes methods for translation among the various data formats.
Though you do not use these methods directly, they serve as the basis for a data type's propertyspecific
methods (called property methods). They include:
• DisplayToLogical — converts a variety of display values into appropriate logical values.
• IsValidDT — performs data validation for the value associated with a property. The
method returns 1 as the first character if the value is valid and 0 as the first character if
it is not valid. When validation is enabled, the IsValidDT method is invoked automatically.
• LogicalToDisplay — converts a logical value to a display value.
• LogicalToOdbc — converts a logical value into an ODBC value (optional).
• LogicalToStorage — converts a logical value into a storage value (optional).
• OdbcToLogical — converts a logical value into a storage value (optional).
Enumerated Properties
• StorageToLogical — converts a database storage value into a logical value (optional).
11.3 Enumerated Properties
Properties can support multiple choice values, also known as enumerated values. To create
such a properties, there are two data type class parameters: VALUELIST and DISPLAYLIST.
To specify a list of valid values for a property, use its VALUELIST parameter. The form of
VALUELIST is a delimiter-separated list of logical values, where the delimiter is the first
character. For instance:
Property Color As %String(VALUELIST = ",red,green,blue");
In this example, VALUELIST specifies that valid possible values are “red” , “green” , and
“blue” , with a comma as its delimiter. Similarly,
Property Color As %String(VALUELIST = " red green blue");
specifies the same list, but with a space as its delimiter.
Using Caché Objects 97