com.healthmarketscience.jackcess.util

Class Joiner

java.lang.Object

com.healthmarketscience.jackcess.util.Joiner

public class Joiner
extends java.lang.Object

Utility for finding rows based on pre-defined, foreign-key table relationships.

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.Object[]	_entryValues
private java.util.List<? extends Index.Column>	_fromCols
private Index	_fromIndex
private IndexCursor	_toCursor

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Joiner(Index fromIndex, IndexCursor toCursor)

Method Summary

Modifier and Type	Method and Description
static Joiner	create(Index fromIndex) Creates a new Joiner based on the given index which backs a foreign-key relationship.
static Joiner	create(Table fromTable, Table toTable) Creates a new Joiner based on the foreign-key relationship between the given "from"" table and the given "to"" table.
Joiner	createReverse() Creates a new Joiner that is the reverse of this Joiner (the "from" and "to" tables are swapped).
boolean	deleteRows(java.util.Map<java.lang.String,?> fromRow) Deletes any rows in the "to" table based on the given columns in the "from" table.
boolean	deleteRows(java.lang.Object[] fromRow) Deletes any rows in the "to" table based on the given columns in the "from" table.
private static boolean	deleteRowsImpl(java.util.Iterator<Row> iter) Deletes all the rows and returns whether or not any "to"" rows were deleted.
Row	findFirstRow(java.util.Map<java.lang.String,?> fromRow) Returns the first row in the "to" table based on the given columns in the "from" table if any, null if there is no matching row.
Row	findFirstRow(java.util.Map<java.lang.String,?> fromRow, java.util.Collection<java.lang.String> columnNames) Returns selected columns from the first row in the "to" table based on the given columns in the "from" table if any, null if there is no matching row.
EntryIterableBuilder	findRows(java.util.Map<java.lang.String,?> fromRow) Returns an Iterator over all the rows in the "to" table based on the given columns in the "from" table.
EntryIterableBuilder	findRows(java.lang.Object[] fromRow) Returns an Iterator with the selected columns over all the rows in the "to" table based on the given columns in the "from" table.
java.util.List<? extends Index.Column>	getColumns()
Index	getFromIndex()
Table	getFromTable()
IndexCursor	getToCursor()
Index	getToIndex()
Table	getToTable()
boolean	hasRows(java.util.Map<java.lang.String,?> fromRow) Returns true if the "to" table has any rows based on the given columns in the "from" table, false otherwise.
boolean	hasRows(java.lang.Object[] fromRow) Returns true if the "to" table has any rows based on the given columns in the "from" table, false otherwise.
private void	toEntryValues(java.util.Map<java.lang.String,?> fromRow) Fills in the _entryValues with the relevant info from the given "from" table row.
private void	toEntryValues(java.lang.Object[] fromRow) Fills in the _entryValues with the relevant info from the given "from" table row.
java.lang.String	toFKString() Returns a pretty string describing the foreign key relationship backing this Joiner.

Methods inherited from class java.lang.Object

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

Field Detail

_fromIndex

private final Index _fromIndex

_fromCols

private final java.util.List<? extends Index.Column> _fromCols

_toCursor

private final IndexCursor _toCursor

_entryValues

private final java.lang.Object[] _entryValues

Constructor Detail

Joiner

private Joiner(Index fromIndex,
               IndexCursor toCursor)

Method Detail

create

public static Joiner create(Table fromTable,
                            Table toTable)
                     throws java.io.IOException

Creates a new Joiner based on the foreign-key relationship between the given "from"" table and the given "to"" table.

Parameters:

fromTable - the "from" side of the relationship

toTable - the "to" side of the relationship

Throws:

java.lang.IllegalArgumentException - if there is no relationship between the given tables

java.io.IOException

create

public static Joiner create(Index fromIndex)
                     throws java.io.IOException

Creates a new Joiner based on the given index which backs a foreign-key relationship. The table of the given index will be the "from" table and the table on the other end of the relationship will be the "to" table.

Parameters:

fromIndex - the index backing one side of a foreign-key relationship

Throws:

java.io.IOException

createReverse

public Joiner createReverse()
                     throws java.io.IOException

Creates a new Joiner that is the reverse of this Joiner (the "from" and "to" tables are swapped).

Throws:

java.io.IOException

getFromTable

public Table getFromTable()

getFromIndex

public Index getFromIndex()

getToTable

public Table getToTable()

getToIndex

public Index getToIndex()

getToCursor

public IndexCursor getToCursor()

getColumns

public java.util.List<? extends Index.Column> getColumns()

hasRows

public boolean hasRows(java.util.Map<java.lang.String,?> fromRow)
                throws java.io.IOException

Returns true if the "to" table has any rows based on the given columns in the "from" table, false otherwise.

Throws:

java.io.IOException

hasRows

public boolean hasRows(java.lang.Object[] fromRow)
                throws java.io.IOException

Returns true if the "to" table has any rows based on the given columns in the "from" table, false otherwise.

Throws:

java.io.IOException

findFirstRow

public Row findFirstRow(java.util.Map<java.lang.String,?> fromRow)
                 throws java.io.IOException

Returns the first row in the "to" table based on the given columns in the "from" table if any, null if there is no matching row.

Parameters:

fromRow - row from the "from" table (which must include the relevant columns for this join relationship)

Throws:

java.io.IOException

findFirstRow

public Row findFirstRow(java.util.Map<java.lang.String,?> fromRow,
                        java.util.Collection<java.lang.String> columnNames)
                 throws java.io.IOException

Returns selected columns from the first row in the "to" table based on the given columns in the "from" table if any, null if there is no matching row.

Parameters:

fromRow - row from the "from" table (which must include the relevant columns for this join relationship)

columnNames - desired columns in the from table row

Throws:

java.io.IOException

findRows

public EntryIterableBuilder findRows(java.util.Map<java.lang.String,?> fromRow)

Returns an Iterator over all the rows in the "to" table based on the given columns in the "from" table.

Parameters:

fromRow - row from the "from" table (which must include the relevant columns for this join relationship)

findRows

public EntryIterableBuilder findRows(java.lang.Object[] fromRow)

Returns an Iterator with the selected columns over all the rows in the "to" table based on the given columns in the "from" table.

Parameters:

fromRow - row from the "from" table (which must include the relevant columns for this join relationship)

deleteRows

public boolean deleteRows(java.util.Map<java.lang.String,?> fromRow)
                   throws java.io.IOException

Deletes any rows in the "to" table based on the given columns in the "from" table.

Parameters:

fromRow - row from the "from" table (which must include the relevant columns for this join relationship)

Returns:

true if any "to" rows were deleted, false otherwise

Throws:

java.io.IOException

deleteRows

public boolean deleteRows(java.lang.Object[] fromRow)
                   throws java.io.IOException

Deletes any rows in the "to" table based on the given columns in the "from" table.

Parameters:

fromRow - row from the "from" table (which must include the relevant columns for this join relationship)

Returns:

true if any "to" rows were deleted, false otherwise

Throws:

java.io.IOException

deleteRowsImpl

private static boolean deleteRowsImpl(java.util.Iterator<Row> iter)
                               throws java.io.IOException

Deletes all the rows and returns whether or not any "to"" rows were deleted.

Throws:

java.io.IOException

toEntryValues

private void toEntryValues(java.util.Map<java.lang.String,?> fromRow)

Fills in the _entryValues with the relevant info from the given "from" table row.

toEntryValues

private void toEntryValues(java.lang.Object[] fromRow)

Fills in the _entryValues with the relevant info from the given "from" table row.

toFKString

public java.lang.String toFKString()

Returns a pretty string describing the foreign key relationship backing this Joiner.