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 Sybase converts the Sybase-specific datatype information provided by the database 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 Sybase maps the given RWDBValue::ValueType into a Sybase-specific type. This mapping is shown in Table 252.

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.

Table 251. Datatype mapping when retrieving data
Adaptive Server Datatypes	RWDBValue::ValueType	C++ Datatype
`char(n)` `varchar(n)` `text`	`String`	RWCString
`nchar(n)` `nvarchar(n)`	`MBString`1	RWDBMBString 1
`unichar(n)`, `univarchar(n)` `unitext`	`UString`	RWBasicUString or RWUString RWUString
`binary(n)` `varbinary(n)` `image` `timestamp`	`Blob`	RWDBBlob
`bit` `tinyint` `smallint`	`Short`	`short int`
`int`	`Long`	`long int`
`decimal(p,0) p <= 9` `numeric(p,0) p <= 9`	`Long`	`long int`
`decimal(p,0) 10 <= p < 19` `numeric(p,0) 10 <= p < 19`	`LongLong`	`long long`
`decimal(p,0) p >= 19` `numeric(p,0) p >= 19`	`Decimal`	RWDecimalPortable
`decimal(p,s)` `numeric(p,s)`	`Decimal`	RWDecimalPortable
`float(p)` `double precision`	`Double`	`double`
`real`	`Float`	`float`
`money` `smallmoney`	`Decimal`	RWDecimalPortable
`datetime` `smalldatetime`2	`DateTime`	RWDateTime

Table 252. Datatype mapping when creating tables
RWDBValue::ValueType	Adaptive Server Datatype
`Char` `UnsignedChar` `Tiny` `UnsignedTiny`	`tinyint`
`String`	if 0 < `length` <= 255, `varchar` using the `storageLength` of the RWDBColumn, otherwise `text`
`WString` `MBString`	if 0 < `length` <= 255, `nvarchar` using the `storageLength` of the RWDBColumn, otherwise `text`
`UString`	`univarchar`, using the `storageLength` of the RWDBColumn
`Blob`	if 0 < `length` <= 255, `varbinary` using the `storageLength` of the RWDBColumn, otherwise `image`
`Short` `UnsignedShort`	`smallint`
`Int` `UnsignedInt`	`int`
`Long` `UnsignedLong`	`int`
`Float`	`real`
`Double`	`float(p)`, using precision of column
`Decimal`	`money` or `decimal(p,s)` using precision and scale of column. See below.
`Date` `DateTime`	`datetime`
`Duration`	Not supported by the Sybase client

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