Data Types

DB Access Module for DB2 CLI User's Guide
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2.3 Data Types

The classes RWDBColumn and RWDBValue have an associated RWDBValue::ValueType that specifies the data type of the database column or field being referenced. Mapping between this data type 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++ data type 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 C++ API Reference Guide.

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 data types and the actual DB2 server types used on the database, please consult IBM's DB2 Call Level Interface Guide and Reference.

Table 1: Type mapping when retrieving data

DB2 Data Type	DB2 SQL Data Type¹	RWDBValue:: ValueType	C++ Data Type
`CHAR` `VARCHAR` `LONG VARCHAR` `CLOB`	`SQL_CHAR` `SQL_VARCHAR` `SQL_LONGVARCHAR` `SQL_CLOB`	`String` or `UString`	*RWCString* or *RWBasicUString*²
`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`	*RWDBDateTime⁴ and RWDateTime*
`GRAPHIC` `VARGRAPHIC` `LONGVARGRAPHIC`⁵	`SQL_GRAPHIC` `SQL_VARGRAPHIC` `SQL_LONGVARGRAPHIC` `SQL_WCHAR` `SQL_WVARCHAR` `SQL_WLONGVARCHAR`	`WString`	*RWWString*
`DECFLOAT`	`SQL_DECFLOAT`	`Decimal`	*RWDecimalPortable*

The current release of the DB Access Module for DB2 CLI does not support the DB2 SQL symbolic data types: BLOB LOCATOR, CLOB LOCATOR, DBCLOB, and DBCLOB LOCATOR.
This mapping is affected by the column type that the result data is bound to. Both datatypes are supported when retrieving string data.
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.
RWDBDateTime is deprecated. Please use RWDateTime.
GRAPHIC, VARGRAPHIC, and LONGVARGRAPHIC types are available only when the DB2 database is Unicode enabled.

Table 2: Type mapping when creating tables

RWDBValue:: ValueType	DB2 Data Type
`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`	`FLOAT`
`Double`	`DOUBLE`
`LongDouble`	Not supported
`Decimal`	`DECIMAL` using the precision and scale of the *RWDBColumn*, if supplied
`Date`	`DATE`
`DateTime`	`TIMESTAMP`
`Duration`	Not supported

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