borland Packages Class Hierarchy dx.dataset Package
java.util.EventListener +----com.borland.dx.dataset.CoerceToListener
Methods
If set, the CoerceToListener
interface is called by implementors of Providers
to coerce data from the data type of the data source to the data type of the Column
component. It is used by QueryDataSet
, ProcedureDataSet
, QueryProvider
and ProcedureProvider
components. This allows an application to coerce column values from one data type to another as the values are sent to a data source, such as a JDBC driver.
Data types are automatically converted during the providing phase according to the table listed in Data type conversions during data providing.
If you set a column's dataType
property, thereby over-riding the default JDBC-to-com.borland
mapping, automatic data type coercion is done. The exception to the automatic type coercion is when converting to and from a String to any
data type other than String (and other conversions involving such differing data types). A VariantException
is thrown in these cases.
To customize the coercion, or to prevent the VariantException
from being thrown in cases as noted in the previous paragraph, wire the
CoerceToListener.coerceToColumn(...)
event.
CoerceFromListener.coerceFromColumn(...)
event
void coerceToColumn(StorageDataSet dataSet, Column column, Variant from, Variant to)Allows an application to control the coercion of a data value from the data source to a column value in
dataSet
.
dataSet
DataSet
in which the Column
exists.
Column
dataSet
parameter.
from
to
parameter.
to
from
parameter must be coerced to.