Package org.apache.druid.query.rowsandcols.concrete

Class ColumnBasedFrameRowsAndColumns

java.lang.Object

org.apache.druid.query.rowsandcols.concrete.AbstractFrameRowsAndColumns

org.apache.druid.query.rowsandcols.concrete.ColumnBasedFrameRowsAndColumns

All Implemented Interfaces:

Closeable, AutoCloseable, FrameRowsAndColumns, RowsAndColumns, CloseableShapeshifter

public class ColumnBasedFrameRowsAndColumns
extends AbstractFrameRowsAndColumns

Constructor Summary

Constructors

Constructor	Description
ColumnBasedFrameRowsAndColumns(Frame frame, RowSignature signature)

Method Summary

Modifier and Type	Method	Description
Column	findColumn(String name)	Finds a column by name.

Methods inherited from class org.apache.druid.query.rowsandcols.concrete.AbstractFrameRowsAndColumns

as, close, equals, getColumnNames, getFrame, getSignature, hashCode, hasSignature, numRows

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ColumnBasedFrameRowsAndColumns

public ColumnBasedFrameRowsAndColumns(Frame frame,
 @Nullable
 RowSignature signature)

Method Details

findColumn

@Nullable
public Column findColumn(String name)

Description copied from interface: RowsAndColumns

Finds a column by name. null is returned if the column is not found. The RowsAndColumns object should not attempt to default not-found columns to pretend as if they exist, instead the user of the RowsAndColumns object should decide the correct semantic interpretation of a column that does not exist. It is expected that most locations will choose to believe that the column does exist and is always null, but there are often optimizations that can effect this same assumption without doing a lot of extra work if the calling code knows that it does not exist.

Parameters:

name - the name of the column to find

Returns:

the Column, if found. null if not found.