Data type mapping between C opaque types and Java
To create an opaque type using Java™, you can use the UDT and UDR Manager facility. For more information, see Work with opaque types.
All opaque data is stored in the database server table in a C struct, which is made up of various DataBlade® API types, as defined in the opaque type. (For more information, see the HCL OneDB™ DataBlade API Programmer's Guide.)
The following table lists the mapping of DataBlade API types to their corresponding Java types.
| DataBlade API type | Java type |
|---|---|
| MI_LO_HANDLE | BLOB or CLOB |
| gl_wchar_t | String |
| mi_boolean | boolean |
| mi_char | String |
| mi_char1 | String |
| mi_date | Date |
| mi_datetime | TimeStamp |
| mi_decimal | BigDecimal |
| mi_double_precision | double |
| mi_int1 | byte |
| mi_int8 | long |
| mi_integer | int |
| mi_interval | Not supported |
| mi_money | BigDecimal |
| mi_numeric | BigDecimal |
| mi_real | float |
| mi_smallint | short |
| mi_string | String |
| mi_unsigned_char1 | String |
| mi_unsigned_int8 | long |
| mi_unsigned_integer | int |
| mi_unsigned_smallint | short |
| mi_wchar | String |
The C struct may contain padding bytes. HCL OneDB JDBC Driver automatically skips these padding bytes to make sure the next data member is properly aligned. Therefore, your Java objects do not have to take care of alignment themselves.