Valid Conversions Between Types in Wrappers and VDP Types

This section describes compatibility mappings between the Java types exported by the wrappers and the data types used by Virtual DataPort in the base relations and views (see section Data Types). When assigning wrappers to base relations it is important to bear these compatibility rules in mind to ensure that the defined schemas for the wrappers and base relations are compatible.

The following table shows mappings of the more common types. These are also the mappings applied automatically by the Virtual DataPort Administration Tool (see Administration Guide).

Automatic conversions between Java types and Virtual DataPort types

Java Types

Virtual DataPort Types

int, java.lang.Short, java.lang.Integer

int

long, java.lang.Long

long

float, java.lang.Float

float

double, java.lang.Double

double

boolean, java.lang.Boolean

boolean

java.math.BigDecimal

decimal

java.lang.String

text

java.util.Date, java.util.Calendar, java.sql.Date, java.sql.Timestamp, java.sql.Time

date

byte[], java.sql.Blob

blob

Any other java data type not specified in this table will be associated by default to the VDP data type text.

Other possible mappings exist between Java types and Virtual DataPort types that can be specified but that are not applied automatically. These can be seen in the following table.

Other valid conversions between Java types and Virtual DataPort types

Java Types

Virtual DataPort Types

java.lang.String

xml

Likewise, wrappers can provide compound elements such as arrays and registers that are directly associated with VDP arrays and registers.