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 208, 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 209.

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.

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.

Table 208. Type mapping when retrieving data
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`	RWCString or RWBasicUString2
`CHAR FOR BIT DATA` `VARCHAR FOR BIT DATA` `LONGVARCHAR FOR BIT DATA` `BLOB`	`SQL_BINARY` `SQL_VARBINARY` `SQL_LONGVARBINARY` `SQL_BLOB`	`Blob`	RWDBBlob
`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`	RWDate
`NUMERIC` `DECIMAL`	`SQL_NUMERIC` `SQL_DECIMAL`	`Decimal`	RWDecimalPortable
`TIMESTAMP` `TIME`3	`SQL_TYPE_TIMESTAMP` `SQL_TYPE_TIME`	`DateTime`	RWDateTime
`GRAPHIC` `VARGRAPHIC` `LONGVARGRAPHIC`4	`SQL_GRAPHIC` `SQL_VARGRAPHIC` `SQL_LONGVARGRAPHIC` `SQL_WCHAR` `SQL_WVARCHAR` `SQL_WLONGVARCHAR`	`WString`	RWWString
`DECFLOAT`	`SQL_DECFLOAT`	`Decimal`	RWDecimalPortable

Table 209. Type mapping when creating tables
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

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