TableExprId.h
Classes
- TableExprId -- The identification of a TaQL selection subject. (full description)
Interface
- Public Members
- TableExprId (uInt rowNumber)
- TableExprId (const RecordInterface&)
- TableExprId (const TableExprData& data)
- Bool byRow() const
- Bool byRecord() const
- Bool byData() const
- uInt rownr() const
- const RecordInterface& record() const
- const TableExprData& data() const
- void setRownr (uInt rownr)
- void setRecord (const RecordInterface&)
Review Status
- Reviewed By:
- UNKNOWN
- Date Reviewed:
- before2004/08/25
Prerequisite
Synopsis
This class provides the user the ability to identify the data objects
to test in a TaQL expression. In this way a TaQL expression is not
limited to tables, but can be used for any set of data.
Three types are available:
- A row number giving the row to test in a table.
- A RecordInterface
object giving the record to test.
- A TableExprData
object giving the abstract base class of an object holding
the data to test. In this way any data can be used.
The TaQL expression must be setup with this in mind by constructing
the appropriate TableExprNode
leaf objects.
When used for tables, the function Table::col
should be used to create the TableExprNode objects for the
table columns to be used in the expression.
For the other cases class
TableExprNodeRecordField
has to be used to know the index of the fields in the expression.
It uses a record (description) for this purpose.
Example
Motivation
This class makes it possible that TaQL can be used in a very versatile way.
Member Description
Construct it from a row number.
TableExprId (const RecordInterface&)
Construct it from a Record object.
Construct it from pointers to data.
Bool byRow() const
Is the id given by row number?
Is the id given as a RecordInterface?
Bool byData() const
Is the id given as a TableExprData?
uInt rownr() const
Get the row number.
const RecordInterface& record() const
Get the Record reference.
Get the data reference.
void setRownr (uInt rownr)
Set the row number.
void setRecord (const RecordInterface&)
Set the record.