public class Projection
extends java.lang.Object
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
source_table_vcolumn_name |
Constructor and Description |
---|
Projection(Schema s)
ctor for full projection
|
Projection(Schema s,
java.lang.String projection)
ctor for partial projection
|
Modifier and Type | Method and Description |
---|---|
static int |
getColumnIndex(java.lang.String projection,
java.lang.String colname)
Get a column's index in a projection.
|
Schema.ColumnSchema |
getColumnSchema(int i)
Get a particular projected column's schema
|
int |
getNumColumns()
Get number of columns in the projection
|
static int |
getNumColumns(java.lang.String projection)
Get number of columns from a projection string
|
Schema |
getProjectionSchema() |
static java.lang.String |
getProjectionStr(java.lang.String[] names)
Get a projection string from a series of column names
|
Schema |
getSchema()
accessor to the projected schema including invalid columns
|
static java.lang.Integer[] |
getVirtualColumnIndices(java.lang.String projection)
Get the indices of all virtual columns
|
static boolean |
isVirtualColumn(java.lang.String name)
if a column name is on a virtual column
|
static Schema |
toSchema(java.lang.String projection)
Get schema from a projection string: all map keys are lost
|
java.lang.String |
toString()
Get the string representation
|
public static final java.lang.String source_table_vcolumn_name
public Projection(Schema s)
public Projection(Schema s, java.lang.String projection) throws org.apache.hadoop.zebra.parser.ParseException
org.apache.hadoop.zebra.parser.ParseException
public static boolean isVirtualColumn(java.lang.String name)
public static java.lang.Integer[] getVirtualColumnIndices(java.lang.String projection)
public Schema getSchema()
public Schema getProjectionSchema()
public Schema.ColumnSchema getColumnSchema(int i)
public java.lang.String toString()
toString
in class java.lang.Object
public int getNumColumns()
public static int getNumColumns(java.lang.String projection)
public static java.lang.String getProjectionStr(java.lang.String[] names)
public static Schema toSchema(java.lang.String projection) throws org.apache.hadoop.zebra.parser.ParseException
org.apache.hadoop.zebra.parser.ParseException
public static int getColumnIndex(java.lang.String projection, java.lang.String colname)
projection
- colname
- Copyright © 2007-2012 The Apache Software Foundation