org.objectweb.medor.datasource.api
Interface Wrapper
- JDBCWrapper, TCWrapper
Represents a wrapper to access data from a QueryLeaf at query evaluation
time.
A Wrapper is associated to a QueryLeaf at a given point of time.
There can be several Wrappers of the same type.
One Wrapper can be associated sequentially to several QueryLeaves.
- Sebastien Chassande-Barrioz
fetchData
public TupleCollection fetchData(QueryLeaf ql,
ParameterOperand[] parameters,
Object connection,
EvaluationMetaData evalmd)
throws EvaluationException
This method links the wrapper to a particular QueryLeaf, and executes
the query on the underlying data store.
ql
- the QueryLeafparameters
- the parameters necessary for obtaining data from the
QueryLeaf (in the case the QueryLeaf contains an expression)connection
- an Object which contains information for connecting
to the DataStore behind the QueryLeaf (could be a JDBC connection, ...)s
- the TupleCollection containing the result of the execution.
EvaluationException
- in case of problems during the evaluation.