| Indicates the columns that must be returned by a read-write VTI's ResultSet.
This method is called only during the runtime execution of the VTI, after it has been
constructed and before the executeQuery() method is called.
At compile time the VTI needs to describe the complete set of columns it can return.
The column identifiers contained in projectedColumns
map to the columns described by the VTI's PreparedStatement's
ResultSetMetaData. The ResultSet returned by
PreparedStatement.executeQuery() must contain
these columns in the order given. Column 1 in this
ResultSet maps the the column of the VTI identified
by projectedColumns[0], column 2 maps to projectedColumns[1] etc.
Any additional columns contained in the ResultSet are ignored
by the database engine. The ResultSetMetaData returned by
ResultSet.getMetaData() must match the ResultSet.
PreparedStatement's ResultSetMetaData column list {"id", "desc", "price", "tax", "brand"}
projectedColumns = { 2, 3, 5}
results in a ResultSet containing at least these 3 columns
{"desc", "price", "brand"}
The JDBC column numbering scheme (1 based) ise used for projectedColumns.
exception:
SQLException - Error processing the request. |