gudusoft.gsqlparser.nodes

Class TJoin

java.lang.Object

gudusoft.gsqlparser.nodes.TParseTreeNode

gudusoft.gsqlparser.nodes.TNodeWithAliasClause

gudusoft.gsqlparser.nodes.TJoin

All Implemented Interfaces:

Visitable

public class TJoin
extends TNodeWithAliasClause

A list of join TCustomSqlStatement.joins represents table sources in following clauses of SQL statement:

• from clause of select statement.
• from clause of delete statement, Specifies an additional FROM clause, This Transact-SQL extension to DELETE allows specifying data from table_source and deleting the corresponding rows from the table in the first FROM clause.
• from clause of update statement, Specifies that a table, view, or derived table source is used to provide the criteria for the update operation.

Each table source in from clause was treated as a join which is type of TJoin.

The reason for this design is that we can treat all table sources in from clause in a uniform way.

Constructor Summary

Constructors

Constructor and Description
TJoin()

Method Summary

Modifier and Type	Method and Description
void	accept(TParseTreeVisitor v) Accept a visitor
void	acceptChildren(TParseTreeVisitor v) Accept a visitor to iterate this class and sub-nodes of this class
TAliasClause	getAliasClause()
TJoin	getJoin()
TJoinItemList	getJoinItems() List of joinItems.
int	getKind() According to the table source in from clause, there are 3 kinds of join.
int	getNestedParen()
TTable	getTable()
boolean	isWithParen()
void	setJoin(TJoin join)
void	setJoinItems(TJoinItemList joinItems)
void	setKind(int kind)
void	setNestedParen(int nestedParen)
void	setTable(TTable table)
void	setWithParen(boolean withParen)

Methods inherited from class gudusoft.gsqlparser.nodes.TNodeWithAliasClause

setAliasClause, toString

Methods inherited from class gudusoft.gsqlparser.nodes.TParseTreeNode

addAllMyTokensToTokenList, appendString, doParse, fastSetString, getColumnNo, getDummyTag, getEndToken, getGsqlparser, getLineNo, getNodeType, getStartToken, init, init, init, init, init, init, removeAllMyTokensFromTokenList, setDummyTag, setEndToken, setEndToken, setEndToken, setEndToken, setGsqlparser, setIncludingComment, setNodeType, setStartToken, setStartToken, setStartToken, setStartToken, setString, toScript

Methods inherited from class java.lang.Object

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

Constructor Detail

TJoin

public TJoin()

Method Detail

setNestedParen

public void setNestedParen(int nestedParen)

getNestedParen

public int getNestedParen()

setWithParen

public void setWithParen(boolean withParen)

isWithParen

public boolean isWithParen()

setJoinItems

public void setJoinItems(TJoinItemList joinItems)

setJoin

public void setJoin(TJoin join)

setTable

public void setTable(TTable table)

setKind

public void setKind(int kind)

getJoinItems

public TJoinItemList getJoinItems()

List of joinItems.

SQL 1:

 select f from t1 left join t2 on t1.f1 = t2.f1 right join t3 on t1.f1 = t3.f1

Text in Item 0 will be: left join t2 on t1.f1 = t2.f1

Text in Item 1 will be: right join t3 on t1.f1 = t3.f1

Check TJoinItem to see how information was organized.

Returns:

getJoin

public TJoin getJoin()

Returns:

this join start with another join( (a as a_alias left join a1 on a1.f1 = a_alias.f1) as a_join ) in SQL:

 select a_join.f1
 from (a as a_alias left join a1 on a1.f1 = a_alias.f1) as a_join
 join b on a_join.f1 = b.f1;
 

getTable

public TTable getTable()

Returns:

this join start with a table(t1) in SQL:

select f from t1 join t2 on t1.f1 = t2.f1

getKind

public int getKind()

According to the table source in from clause, there are 3 kinds of join.

• TBaseType.join_source_fake, it's a fake join like

  select f from t1

  the whole from clause was represented by this class, you can get text representation of this from clause by using toString() method, it returns "t1" .

  and table t1 can be fetch from getTable().

• TBaseType.join_source_table,

  select f from t1 join t2 on t1.f1 = t2.f1

  the whole from clause was represented by this class, you can get text representation of this from clause by using toString() method, it returns "t1 join t2 on t1.f1 = t2.f1".

  t1 can be fetch from getTable().

• TBaseType.join_source_join,

   select a_join.f1
   from (a as a_alias left join a1 on a1.f1 = a_alias.f1) as a_join
   join b on a_join.f1 = b.f1;
   

  the whole from clause was represented by this class, you can get text representation of this from clause by using toString() method, it returns "(a as a_alias left join a1 on a1.f1 = a_alias.f1) as a_join join b on a_join.f1 = b.f1".

  (a as a_alias left join a1 on a1.f1 = a_alias.f1) can be fetched from getJoin().

Returns:

getAliasClause

public TAliasClause getAliasClause()

Overrides:

getAliasClause in class TNodeWithAliasClause

Returns:

alias of getJoin(), valid only when = TBaseType#join_source_join. In this SQL, alias is "as a_join"

 select a_join.f1
 from (a as a_alias left join a1 on a1.f1 = a_alias.f1) as a_join
 join b on a_join.f1 = b.f1;
 

But in this SQL, alias is null, "as t1" is the alias of t1.

 select f from t as t1 join t2 on t1.f1 = t2.f1
 

accept

public void accept(TParseTreeVisitor v)

Description copied from class: TParseTreeNode

Accept a visitor

Specified by:

accept in interface Visitable

Overrides:

accept in class TParseTreeNode

Parameters:

v - visitor is a descendant class of TParseTreeVisitor

acceptChildren

public void acceptChildren(TParseTreeVisitor v)

Description copied from class: TParseTreeNode

Accept a visitor to iterate this class and sub-nodes of this class

Specified by:

acceptChildren in interface Visitable

Overrides:

acceptChildren in class TParseTreeNode

Parameters:

v - visitor is a descendant class of TParseTreeVisitor