org.apache.empire.db

Class DBIndex

java.lang.Object

org.apache.empire.db.DBObject

org.apache.empire.db.DBIndex

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

DBExpressionIndex

public class DBIndex
extends DBObject

This class handles the primary key for the tables. The primary key contains one or more columns.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	PRIMARYKEY SQL Primary key index
static int	STANDARD SQL Standard index
static int	UNIQUE SQL Unique index

Constructor Summary

Constructors

Constructor and Description
DBIndex(String name, int type, DBColumn[] columns) Constructs a DBIndex object set the specified parameters to this object.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contains(DBColumn col) Checks if this index contains the column col
int	getColumnPos(DBColumn col) Gets the position of a specified DBColumn object.
DBColumn[]	getColumns() Returns the columns belonging to this index.
DBDatabase	getDatabase() Returns the database object to which this object belongs to.
DBExpr[]	getExpressions() Returns the columnExpressions belonging to this index.
String	getFullName() Returns the full qualified table name.
String	getName() Returns the primary key name.
DBTable	getTable() returns the table this index belongs to.
int	getType() Returns the index type.

Methods inherited from class java.lang.Object

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

Field Detail

STANDARD

public static final int STANDARD

SQL Standard index

See Also:

Constant Field Values

UNIQUE

public static final int UNIQUE

SQL Unique index

See Also:

Constant Field Values

PRIMARYKEY

public static final int PRIMARYKEY

SQL Primary key index

See Also:

Constant Field Values

Constructor Detail

DBIndex

public DBIndex(String name,
       int type,
       DBColumn[] columns)

Constructs a DBIndex object set the specified parameters to this object.

Parameters:

name - the primary key name

type - the primary key type (only PRIMARYKEY)

columns - an array of one or more columns of the primary key

Method Detail

getTable

public DBTable getTable()

returns the table this index belongs to. Valid only if the index has been added to a table (DBTable.addIndex)

Returns:

the corresponding table

getDatabase

public DBDatabase getDatabase()

Description copied from class: DBObject

Returns the database object to which this object belongs to. For the database object itself this function will return the this pointer.

Specified by:

getDatabase in class DBObject

Returns:

the database object

getName

public String getName()

Returns the primary key name.

Returns:

the primary key name

getColumns

public DBColumn[] getColumns()

Returns the columns belonging to this index.

Returns:

the columns belonging to this index

getExpressions

public DBExpr[] getExpressions()

Returns the columnExpressions belonging to this index.

Returns:

the columnExpressions belonging to this index

getFullName

public String getFullName()

Returns the full qualified table name.

Returns:

the full qualified table name

getType

public int getType()

Returns the index type.

Returns:

the type of this index (PRIMARYKEY, UNIQUE, STANDARD)

contains

public boolean contains(DBColumn col)

Checks if this index contains the column col

Parameters:

col - the column

Returns:

true if this index contains this column

getColumnPos

public int getColumnPos(DBColumn col)

Gets the position of a specified DBColumn object.

Parameters:

col - the column

Returns:

the position or -1 if the column was not found