de.unknownreality.dataframe.index

Class Indices

java.lang.Object

de.unknownreality.dataframe.index.Indices

public class Indices
extends Object

Created by Alex on 27.05.2016.

Field Summary

Fields

Modifier and Type	Field and Description
static String	PRIMARY_KEY_NAME

Constructor Summary

Constructors

Constructor and Description
Indices(DataFrame dataFrame) Creates an index for a data frame

Method Summary

Modifier and Type	Method and Description
void	addIndex(Index index) Adds a new index using one or more columns
void	addIndex(String name, boolean unique, DataFrameColumn... columns) Creates and adds a new index using one or more columns
void	addIndex(String name, DataFrameColumn... columns) Creates and adds a new index using one or more columns
void	clear()
void	clearValues() Clears the values of all indices
boolean	containsIndex(String name) Returns true if an index with the specified name exists
void	copyTo(DataFrame dataFrame) Copies all indices into another data frame
Collection<Integer>	find(String name, Comparable... values) Returns the row numbers for a index and a set of values for the index
Integer	findByPrimaryKey(Comparable... values) Returns the row number for a set of primary key values
Integer	findFirst(String name, Comparable... values) Returns the first found row number for a index and a set of values for the index If no row is found, null is returned
int	indicesCount() returns the number of indices
boolean	isIndexColumn(DataFrameColumn column) Returns true if the specified column is part of at least one index.
void	remove(DataRow dataRow) Removes a row from all indices
void	removeColumn(DataFrameColumn column) Removes all indices that contain a certain column
void	removeIndex(String name) Removes an index based on its name
void	replace(DataFrameColumn existing, DataFrameColumn replacement) Replaces an existing column with a replacement column All existing indices will be updated
void	setPrimaryKey(DataFrameColumn... columns) sets the primary key using one or more columns
void	update(DataRow dataRow) Updates a data row in all available indices
void	updateAllRows() Updates all rows in all available indices
void	updateColumn(DataFrameColumn column) Updates all indices that contain a certain row.
void	updateValue(DataFrameColumn column, DataRow dataRow) Updates the specified in each index that contains the specified column

Methods inherited from class java.lang.Object

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

Field Detail

PRIMARY_KEY_NAME

public static final String PRIMARY_KEY_NAME

See Also:

Constant Field Values

Constructor Detail

Indices

public Indices(DataFrame dataFrame)

Creates an index for a data frame

Parameters:

dataFrame - input data frame

Method Detail

isIndexColumn

public boolean isIndexColumn(DataFrameColumn column)

Returns true if the specified column is part of at least one index.

Parameters:

column - input column

Returns:

true if column is part of an index

replace

public void replace(DataFrameColumn existing,
                    DataFrameColumn replacement)

Replaces an existing column with a replacement column All existing indices will be updated

Parameters:

existing - existing column

replacement - replacement column

copyTo

public void copyTo(DataFrame dataFrame)

Copies all indices into another data frame

Parameters:

dataFrame - data frame the indices are copied to

update

public void update(DataRow dataRow)

Updates a data row in all available indices

Parameters:

dataRow - data row to update

updateAllRows

public void updateAllRows()

Updates all rows in all available indices

find

public Collection<Integer> find(String name,
                                Comparable... values)

Returns the row numbers for a index and a set of values for the index

Parameters:

name - name of the index

values - row values

Returns:

row numbers matching the row values

findFirst

public Integer findFirst(String name,
                         Comparable... values)

Returns the first found row number for a index and a set of values for the index If no row is found, null is returned

Parameters:

name - name of the index

values - row values

Returns:

row number matching the row values or null

findByPrimaryKey

public Integer findByPrimaryKey(Comparable... values)

Returns the row number for a set of primary key values

Parameters:

values - primary key values

Returns:

row number matching the row values

addIndex

public void addIndex(String name,
                     DataFrameColumn... columns)

Creates and adds a new index using one or more columns

Parameters:

name - name of the index

columns - columns the index is based on

addIndex

public void addIndex(String name,
                     boolean unique,
                     DataFrameColumn... columns)

Creates and adds a new index using one or more columns

Parameters:

name - name of the index

unique - allow only unique values in this index

columns - columns the index is based on

addIndex

public void addIndex(Index index)

Adds a new index using one or more columns

Parameters:

index - index to add

indicesCount

public int indicesCount()

returns the number of indices

Returns:

number of indices

setPrimaryKey

public void setPrimaryKey(DataFrameColumn... columns)

sets the primary key using one or more columns

Parameters:

columns - columns the index is based on

containsIndex

public boolean containsIndex(String name)

Returns true if an index with the specified name exists

Parameters:

name - name of index

Returns:

true if index with input name exists

clearValues

public void clearValues()

Clears the values of all indices

updateValue

public void updateValue(DataFrameColumn column,
                        DataRow dataRow)

Updates the specified in each index that contains the specified column

Parameters:

column - index column

dataRow - row to update

updateColumn

public void updateColumn(DataFrameColumn column)

Updates all indices that contain a certain row. All rows in the data frame are updated

Parameters:

column - update column

remove

public void remove(DataRow dataRow)

Removes a row from all indices

Parameters:

dataRow - row to remove

removeIndex

public void removeIndex(String name)

Removes an index based on its name

Parameters:

name - name of index to remove

removeColumn

public void removeColumn(DataFrameColumn column)

Removes all indices that contain a certain column

Parameters:

column - column to remove

clear

public void clear()