Data types

A column of data stored on a data source has an SQL data type.

HCL OneDB™ ODBC Driver maps HCL OneDB-specific SQL data types to ODBC SQL data types, which are defined in the ODBC SQL grammar. (The driver returns these mappings through SQLGetTypeInfo. It also uses the ODBC SQL data types to describe the data types of columns and parameters in SQLColAttributes and SQLDescribeCol).

Each SQL data type corresponds to an ODBC C data type. By default, the driver assumes that the C data type of a storage location corresponds to the SQL data type of the column or parameter to which the location is bound. If the C data type of a storage location is not the default C data type, the application can specify the correct C data type with the TargetType argument for SQLBindCol, the fCType argument for SQLGetData, and the ValueType argument in SQLBindParameter. Before the driver returns data from the data source, it converts the data to the specified C data type. Before the driver sends data to the data source, it converts the data from the specified C data type to the SQL data type.

The HCL OneDB data type names differ from the Microsoft™ ODBC data type names. For information about these differences, see the appendix about data types in the HCL OneDB ODBC Driver Programmer's Manual.