Datatypes
The classes RWDBColumn and RWDBValue have an associated RWDBValue::ValueType that specifies the datatype of the database column or field being referenced. Mapping between this datatype and the database vendor type runs in both directions:
When fetching data or retrieving information about tables, the DB Access Module for DB2 CLI converts the SQL datatype provided by DB2’s ODBC implementation into RWDBValue::ValueTypes. This mapping is shown in Table 1, which also gives the C++ datatype corresponding to the RWDBValue::ValueType.When creating tables, the DB Access Module for DB2 CLI maps the given RWDBValue::ValueType to a DB2 server type. This mapping is shown in Table 2.The RWDBValue::ValueTypes, accessible through the type() method, are uniform across all Access Modules.
For a complete explanation of the DB Interface Module data model, see Chapter 7, “The Data Model,” in the DB Interface Module User’s Guide, and RWDBValue in the SourcePro API Reference Guide.
NOTE: We update the mapping tables regularly, but Rogue Wave cannot be responsible for changes made by other vendors. For the latest information on mappings between the DB2 SQL datatypes and the actual DB2 server types used on the database, please consult IBM's DB2 Call Level Interface Guide and Reference.
DB2 Datatype | DB2 SQL Datatype1 | RWDBValue:: ValueType | C++ Datatype |
|---|---|---|---|
CHAR VARCHAR LONG VARCHAR CLOB | SQL_CHAR SQL_VARCHAR SQL_LONGVARCHAR SQL_CLOB | String or UString | |
CHAR FOR BIT DATA VARCHAR FOR BIT DATA LONGVARCHAR FOR BIT DATA BLOB | SQL_BINARY SQL_VARBINARY SQL_LONGVARBINARY SQL_BLOB | Blob | |
SMALLINT | SQL_SMALLINT | Short | short int |
BIGINT | SQL_BIGINT | LongLong | long long |
INTEGER | SQL_INTEGER | Long | long int |
DOUBLE FLOAT | SQL_DOUBLE SQL_FLOAT | Double | double |
REAL | SQL_REAL | Float | float |
DATE | SQL_TYPE_DATE | Date | |
NUMERIC DECIMAL | SQL_NUMERIC SQL_DECIMAL | Decimal | |
SQL_TYPE_TIMESTAMP SQL_TYPE_TIME | DateTime | ||
SQL_GRAPHIC SQL_VARGRAPHIC SQL_LONGVARGRAPHIC SQL_WCHAR SQL_WVARCHAR SQL_WLONGVARCHAR | WString | ||
DECFLOAT | SQL_DECFLOAT | Decimal |
1 The current release of the DB Access Module for DB2 CLI does not support the DB2 SQL symbolic datatypes: BLOB LOCATOR, CLOB LOCATOR, DBCLOB, and DBCLOB LOCATOR.
2 This mapping is affected by the column type that the result data is bound to. Both datatypes are supported when retrieving string data.
3 Values of type TIMESTAMP and TIME are affected by the time zone setting on either RWDBDatabase or RWDBConnection while sending and retrieving data. The time zone setting can be set programmatically with the timeZone() method in each of these classes.
4 GRAPHIC, VARGRAPHIC, and LONGVARGRAPHIC types are available only when the DB2 database is Unicode enabled.
RWDBValue:: ValueType | DB2 Datatype |
|---|---|
Char UnsignedChar | SMALLINT |
String UString | If 0 < length < 255, VARCHAR using the storageLength of the RWDBColumn If length > 32700, CLOB using the storageLength of the RWDBColumn, Else LONG VARCHAR |
WString MBString | Not supported |
Blob | If 0 < length < 255 VARCHAR FOR BIT DATA using the storageLength of the RWDBColumn If length > 32700, BLOB using the storageLength of the RWDBColumn Else LONG VARCHAR FOR BIT DATA |
Short UnsignedShort | SMALLINT |
Int UnsignedInt | INTEGER |
Long UnsignedLong | INTEGER |
LongLong UnsignedLongLong | BIGINT |
Float | REAL |
Double | DOUBLE |
LongDouble | Not supported |
Decimal | DECIMAL using the precision and scale of the RWDBColumn, if supplied |
Date | DATE |
DateTime | TIMESTAMP |
TimeTuple | Not supported |
TimeTupleOffset | Not supported |
Duration | Not supported |
