java.lang.Object
- com.mckoi.database.Table
- - com.mckoi.database.AbstractDataTable
  - - com.mckoi.database.DataTableFilter

All Implemented Interfaces:

RootTable, TableDataSource
```
public class DataTableFilter
extends AbstractDataTable
```
This object sits on top of a DataTable object filtering out certain types of calls. We could use this object to implement a ReferenceTable which can be used to declare a new table name with a DataTable type. We also use this object to implement a filter for column removals.

Nested Class Summary
- Nested classes/interfaces inherited from class com.mckoi.database.Table
  Table.TableVariableResolver

Field Summary

Fields
Modifier and Type Field Description

protected AbstractDataTable parent
The parent DataTable object.
- Fields inherited from class com.mckoi.database.Table
  DEBUG_QUERY

Constructor Summary

Constructors
Modifier Constructor Description

protected DataTableFilter(AbstractDataTable table)
The Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) void`	`addDataTableListener(DataTableListener listener)`	Adds a DataTableListener to the DataTable objects at the root of this table tree hierarchy.
`int`	`findFieldName(Variable v)`	Given a fully qualified variable field name, ie.
`TObject`	`getCellContents(int column, int row)`	Returns an object that represents the information in the given cell in the table.
`int`	`getColumnCount()`	Returns the number of columns in the table.
`Database`	`getDatabase()`	Returns the Database context for this filtered table.
`DataTableDef`	`getDataTableDef()`	Returns a DataTableDef object that defines the name of the table and the layout of the columns of the table.
`Variable`	`getResolvedVariable(int column)`	Returns a fully qualified Variable object that represents the name of the column at the given index.
`int`	`getRowCount()`	Returns the number of rows stored in the table.
`(package private) SelectableScheme`	`getSelectableSchemeFor(int column, int original_column, Table table)`	Returns a SelectableScheme for the given column in the given VirtualTable row domain.
`boolean`	`hasRootsLocked()`	Returns true if the table has its row roots locked (via the lockRoot(int) method.
`void`	`lockRoot(int lock_key)`	Locks the root table(s) of this table so that it is impossible to overwrite the underlying rows that may appear in this table.
`(package private) void`	`removeDataTableListener(DataTableListener listener)`	Removes a DataTableListener from the DataTable objects at the root of this table tree hierarchy.
`(package private) RawTableInformation`	`resolveToRawTable(RawTableInformation info)`	Return the list of DataTable and row sets that make up the raw information in this table.
`RowEnumeration`	`rowEnumeration()`	Returns an Enumeration of the rows in this table.
`(package private) void`	`setToRowTableDomain(int column, IntegerVector row_set, TableDataSource ancestor)`	Given a set, this trickles down through the Table hierarchy resolving the given row_set to a form that the given ancestor understands.
`void`	`unlockRoot(int lock_key)`	Unlocks the root tables so that the underlying rows may once again be used if they are not locked and have been removed.

Methods inherited from class com.mckoi.database.AbstractDataTable
getTableName, toString, typeEquals

Methods inherited from class com.mckoi.database.Table
all, allColumnMatchesValue, allRowsIn, allRowsNotIn, any, columnContainsCell, columnContainsValue, columnMatchesValue, columnMerge, compareCells, Debug, distinct, distinct, dumpTo, emptySelect, exhaustiveSelect, fastFindFieldName, getColumnDefAt, getColumnScheme, getFirstCellContent, getFirstCellContent, getLastCellContent, getLastCellContent, getSingleCellContent, getSingleCellContent, getSystem, getTableAccessState, getTTypeForColumn, getTTypeForColumn, getVariableResolver, join, orderByColumn, orderByColumn, orderByColumn, orderByColumns, orderedRowList, outside, printGraph, rangeSelect, selectAll, selectAll, selectFirst, selectFromPattern, selectFromRegex, selectLast, selectRange, selectRest, selectRows, selectRows, selectRows, simpleJoin, simpleSelect, singleRowSelect, toMap, union

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - parent
```
protected AbstractDataTable parent
```
    The parent DataTable object.
- Constructor Detail
  - DataTableFilter
```
protected DataTableFilter(AbstractDataTable table)
```
    The Constructor. A filter can only sit on top of a DataTable or DataTableFilter table. ISSUE: we could make an interface for this. This is a bit of a hack.
- Method Detail
  - getDatabase
```
public Database getDatabase()
```
    Returns the Database context for this filtered table.
    
    Specified by:
    
    getDatabase in class Table
  - getColumnCount
```
public int getColumnCount()
```
    Returns the number of columns in the table.
    
    Specified by:
    
    getColumnCount in class Table
  - getRowCount
```
public final int getRowCount()
```
    Returns the number of rows stored in the table.
    
    Specified by:
    
    getRowCount in interface TableDataSource
    
    Specified by:
    
    getRowCount in class Table
  - findFieldName
```
public int findFieldName(Variable v)
```
    Given a fully qualified variable field name, ie. 'APP.CUSTOMER.CUSTOMERID' this will return the column number the field is at. Returns -1 if the field does not exist in the table.
    
    Specified by:
    
    findFieldName in class Table
  - getResolvedVariable
```
public Variable getResolvedVariable(int column)
```
    Returns a fully qualified Variable object that represents the name of the column at the given index. For example, new Variable(new TableName("APP", "CUSTOMER"), "ID")
    
    Specified by:
    
    getResolvedVariable in class Table
  - getSelectableSchemeFor
```
final SelectableScheme getSelectableSchemeFor(int column,
                                              int original_column,
                                              Table table)
```
    Returns a SelectableScheme for the given column in the given VirtualTable row domain. Slight Hack: When we are asking for a selectable scheme for a reference table, we must defer the 'table' variable to the parent.
    
    Specified by:
    
    getSelectableSchemeFor in class Table
  - setToRowTableDomain
```
final void setToRowTableDomain(int column,
                               IntegerVector row_set,
                               TableDataSource ancestor)
```
    Given a set, this trickles down through the Table hierarchy resolving the given row_set to a form that the given ancestor understands. Say you give the set { 0, 1, 2, 3, 4, 5, 6 }, this function may check down three levels and return a new 7 element set with the rows fully resolved to the given ancestors domain.
    Slight Hack: When we are asking for a selectable scheme for a reference table, we must defer the 'table' variable to the parent.
    
    Specified by:
    
    setToRowTableDomain in class Table
  - resolveToRawTable
```
final RawTableInformation resolveToRawTable(RawTableInformation info)
```
    Return the list of DataTable and row sets that make up the raw information in this table. This is identical to the DataTable method except it puts this table as the owner of the row set.
    
    Specified by:
    
    resolveToRawTable in class Table
  - getCellContents
```
public final TObject getCellContents(int column,
                                     int row)
```
    Returns an object that represents the information in the given cell in the table. This will generally be an expensive algorithm, so calls to it should be kept to a minimum. Note that the offset between two rows is not necessarily 1.
    
    Specified by:
    
    getCellContents in interface TableDataSource
    
    Specified by:
    
    getCellContents in class Table
  - rowEnumeration
```
public final RowEnumeration rowEnumeration()
```
    Returns an Enumeration of the rows in this table. The Enumeration is a fast way of retrieving consequtive rows in the table.
    
    Specified by:
    
    rowEnumeration in interface TableDataSource
    
    Specified by:
    
    rowEnumeration in class Table
  - getDataTableDef
```
public DataTableDef getDataTableDef()
```
    Returns a DataTableDef object that defines the name of the table and the layout of the columns of the table. Note that for tables that are joined with other tables, the table name and schema for this object become mangled. For example, a table called 'PERSON' joined with a table called 'MUSIC' becomes a table called 'PERSON#MUSIC' in a null schema.
    
    Specified by:
    
    getDataTableDef in interface TableDataSource
    
    Specified by:
    
    getDataTableDef in class Table
  - addDataTableListener
```
void addDataTableListener(DataTableListener listener)
```
    Adds a DataTableListener to the DataTable objects at the root of this table tree hierarchy. If this table represents the join of a number of tables then the DataTableListener is added to all the DataTable objects at the root.
    A DataTableListener is notified of all modifications to the raw entries of the table. This listener can be used for detecting changes in VIEWs, for triggers or for caching of common queries.
    
    Specified by:
    
    addDataTableListener in class Table
  - removeDataTableListener
```
void removeDataTableListener(DataTableListener listener)
```
    Removes a DataTableListener from the DataTable objects at the root of this table tree hierarchy. If this table represents the join of a number of tables, then the DataTableListener is removed from all the DataTable objects at the root.
    
    Specified by:
    
    removeDataTableListener in class Table
  - lockRoot
```
public void lockRoot(int lock_key)
```
    Locks the root table(s) of this table so that it is impossible to overwrite the underlying rows that may appear in this table. This is used when cells in the table need to be accessed 'outside' the lock. So we may have late access to cells in the table. 'lock_key' is a given key that will also unlock the root table(s). NOTE: This is nothing to do with the 'LockingMechanism' object.
    
    Specified by:
    
    lockRoot in class Table
  - unlockRoot
```
public void unlockRoot(int lock_key)
```
    Unlocks the root tables so that the underlying rows may once again be used if they are not locked and have been removed. This should be called some time after the rows have been locked.
    
    Specified by:
    
    unlockRoot in class Table
  - hasRootsLocked
```
public boolean hasRootsLocked()
```
    Returns true if the table has its row roots locked (via the lockRoot(int) method.
    
    Specified by:
    
    hasRootsLocked in class Table

Class DataTableFilter

Nested Class Summary

Nested classes/interfaces inherited from class com.mckoi.database.Table

Field Summary

Fields inherited from class com.mckoi.database.Table

Constructor Summary

Method Summary

Methods inherited from class com.mckoi.database.AbstractDataTable

Methods inherited from class com.mckoi.database.Table

Methods inherited from class java.lang.Object

Field Detail

parent

Constructor Detail

DataTableFilter

Method Detail

getDatabase

getColumnCount

getRowCount

findFieldName

getResolvedVariable

getSelectableSchemeFor

setToRowTableDomain

resolveToRawTable

getCellContents

rowEnumeration

getDataTableDef

addDataTableListener

removeDataTableListener

lockRoot

unlockRoot

hasRootsLocked