org.teiid.query.sql.lang

Class From

java.lang.Object

org.teiid.query.sql.lang.From

All Implemented Interfaces:

Cloneable, LanguageObject

public class From
extends Object
implements LanguageObject

Represents a FROM clause in a SELECT query. The from clause holds a set of FROM subclauses. Each FROM subclause can be either a single group (UnaryFromClause) or a join predicate (JoinPredicate).

Nested Class Summary

Nested classes/interfaces inherited from interface org.teiid.query.sql.LanguageObject

LanguageObject.Util

Constructor Summary

Constructors

Constructor and Description
From() Constructs a default instance of this class.
From(List<? extends FromClause> parameters) Constructs an instance of this class from an ordered set of from clauses

Method Summary

Modifier and Type	Method and Description
void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
void	addClause(FromClause clause) Add a clause to the FROM
void	addClauses(Collection<? extends FromClause> toAdd) Add clauses to the FROM
void	addGroup(GroupSymbol group) Adds a new group to the list (it will be wrapped in a UnaryFromClause)
void	addGroups(Collection<GroupSymbol> groups) Adds a new collection of groups to the list
Object	clone() Return copy of this From clause.
boolean	containsGroup(GroupSymbol group) Checks if a group is in the From
boolean	equals(Object obj) Compare two Froms for equality.
List<FromClause>	getClauses() Get all the clauses in FROM
List<GroupSymbol>	getGroups() Returns an ordered list of the groups in all sub-clauses.
int	hashCode() Get hashcode for From.
void	setClauses(List<FromClause> clauses) Set all the clauses
String	toString() Returns a string representation of an instance of this class.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

From

public From()

Constructs a default instance of this class.

From

public From(List<? extends FromClause> parameters)

Constructs an instance of this class from an ordered set of from clauses

Parameters:

parameters - The ordered list of from clauses

Method Detail

addClause

public void addClause(FromClause clause)

Add a clause to the FROM

Parameters:

clause - Add a clause to the FROM

addClauses

public void addClauses(Collection<? extends FromClause> toAdd)

Add clauses to the FROM

Parameters:

clauses - Collection of FromClauses

getClauses

public List<FromClause> getClauses()

Get all the clauses in FROM

Returns:

List of FromClause

setClauses

public void setClauses(List<FromClause> clauses)

Set all the clauses

Parameters:

clauses - List of FromClause

addGroup

public void addGroup(GroupSymbol group)

Adds a new group to the list (it will be wrapped in a UnaryFromClause)

Parameters:

group - Group to add

addGroups

public void addGroups(Collection<GroupSymbol> groups)

Adds a new collection of groups to the list

Parameters:

groups - Collection of GroupSymbol

getGroups

public List<GroupSymbol> getGroups()

Returns an ordered list of the groups in all sub-clauses.

Returns:

List of GroupSymbol

containsGroup

public boolean containsGroup(GroupSymbol group)

Checks if a group is in the From

Parameters:

group - Group to check for

Returns:

True if the From contains the group

acceptVisitor

public void acceptVisitor(LanguageVisitor visitor)

Description copied from interface: LanguageObject

Method for accepting a visitor. It is the responsibility of the language object to call back on the visitor.

Specified by:

acceptVisitor in interface LanguageObject

Parameters:

visitor - Visitor being used

clone

public Object clone()

Return copy of this From clause.

Specified by:

clone in interface LanguageObject

Overrides:

clone in class Object

Returns:

Deep clone of this object

equals

public boolean equals(Object obj)

Compare two Froms for equality. Order is not important in the from, so this is a set comparison.

Overrides:

equals in class Object

hashCode

public int hashCode()

Get hashcode for From. WARNING: The hash code relies on the variables in the select, so changing the variables will change the hash code, causing a select to be lost in a hash structure. Do not hash a From if you plan to change it.

Overrides:

hashCode in class Object

toString

public String toString()

Returns a string representation of an instance of this class.

Overrides:

toString in class Object

Returns:

String representation of object