Package com.mckoi.database
Class CompositeTable
- java.lang.Object
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- com.mckoi.database.Table
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- com.mckoi.database.CompositeTable
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- All Implemented Interfaces:
RootTable
,TableDataSource
public class CompositeTable extends Table implements RootTable
A composite of two or more datasets used to implement UNION, INTERSECTION, and DIFFERENCE.- Author:
- Tobias Downer
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Field Summary
Fields Modifier and Type Field Description static int
EXCEPT
The composite function for finding the difference of the tables.static int
INTERSECT
The composite function for finding the interestion of the tables.static int
UNION
The composite function for finding the union of the tables.-
Fields inherited from class com.mckoi.database.Table
DEBUG_QUERY
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Constructor Summary
Constructors Constructor Description CompositeTable(Table[] composite_list)
Consturcts the composite table assuming the first item in the list is the master table.CompositeTable(Table master_table, Table[] composite_list)
Constructs the composite table given the 'master_table' (the field structure this composite dataset is based on), and a list of tables to be the composite of this table.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description 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 object that this table is derived from.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.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.RowEnumeration
rowEnumeration()
Returns an Enumeration of the rows in this table.void
setupIndexesForCompositeFunction(int function, boolean all)
Sets up the indexes in this composite table by performing for composite function on the tables.boolean
typeEquals(RootTable table)
This is function is used to check that two root tables are identical.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.Table
all, allColumnMatchesValue, 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, join, orderByColumn, orderByColumn, orderByColumn, orderByColumns, orderedRowList, outside, printGraph, rangeSelect, selectAll, selectAll, selectFirst, selectLast, selectRange, selectRest, simpleJoin, simpleSelect, singleRowSelect, toMap, toString, union
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Field Detail
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UNION
public static int UNION
The composite function for finding the union of the tables.
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INTERSECT
public static int INTERSECT
The composite function for finding the interestion of the tables.
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EXCEPT
public static int EXCEPT
The composite function for finding the difference of the tables.
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Constructor Detail
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CompositeTable
public CompositeTable(Table master_table, Table[] composite_list)
Constructs the composite table given the 'master_table' (the field structure this composite dataset is based on), and a list of tables to be the composite of this table. The 'master_table' must be one of the elements of the 'composite_list' array.NOTE: This does not set up table indexes for a composite function.
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CompositeTable
public CompositeTable(Table[] composite_list)
Consturcts the composite table assuming the first item in the list is the master table.
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Method Detail
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setupIndexesForCompositeFunction
public void setupIndexesForCompositeFunction(int function, boolean all)
Sets up the indexes in this composite table by performing for composite function on the tables. If the 'all' parameter is true then duplicate rows are removed.
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getDatabase
public Database getDatabase()
Description copied from class:Table
Returns the Database object that this table is derived from.- Specified by:
getDatabase
in classTable
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getColumnCount
public int getColumnCount()
Description copied from class:Table
Returns the number of columns in the table.- Specified by:
getColumnCount
in classTable
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getRowCount
public int getRowCount()
Description copied from class:Table
Returns the number of rows stored in the table.- Specified by:
getRowCount
in interfaceTableDataSource
- Specified by:
getRowCount
in classTable
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findFieldName
public int findFieldName(Variable v)
Description copied from class:Table
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 classTable
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getDataTableDef
public DataTableDef getDataTableDef()
Description copied from class:Table
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 interfaceTableDataSource
- Specified by:
getDataTableDef
in classTable
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getResolvedVariable
public Variable getResolvedVariable(int column)
Description copied from class:Table
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 classTable
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getCellContents
public TObject getCellContents(int column, int row)
Description copied from class:Table
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. Use 'rowEnumeration' to get the contents of a set.- Specified by:
getCellContents
in interfaceTableDataSource
- Specified by:
getCellContents
in classTable
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rowEnumeration
public RowEnumeration rowEnumeration()
Description copied from class:Table
Returns an Enumeration of the rows in this table. Each call to 'RowEnumeration.nextRowIndex()' returns the next valid row in the table. Note that the order that rows are retreived depend on a number of factors. For a DataTable the rows are accessed in the order they are in the data file. For a VirtualTable, the rows are accessed in the order of the last select operation.If you want the rows to be returned by a specific column order then use the 'selectxxx' methods.
- Specified by:
rowEnumeration
in interfaceTableDataSource
- Specified by:
rowEnumeration
in classTable
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lockRoot
public void lockRoot(int lock_key)
Description copied from class:Table
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.
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unlockRoot
public void unlockRoot(int lock_key)
Description copied from class:Table
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 classTable
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hasRootsLocked
public boolean hasRootsLocked()
Description copied from class:Table
Returns true if the table has its row roots locked (via the lockRoot(int) method.- Specified by:
hasRootsLocked
in classTable
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typeEquals
public boolean typeEquals(RootTable table)
Description copied from interface:RootTable
This is function is used to check that two root tables are identical. This is used if we need to chect that the form of the table is the same. Such as in a union operation, when we can only union two tables with the identical columns.- Specified by:
typeEquals
in interfaceRootTable
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