Package org.datanucleus.store.rdbms.sql

Class SQLJoin

java.lang.Object

org.datanucleus.store.rdbms.sql.SQLJoin

public class SQLJoin
extends java.lang.Object

Representation of a join in an SQL statement. The join is of a type (see ANSI SQL), and with inner/left outer/right outer is accompanied by join condition(s), joining from the source table to the target table via columns. Additionally other conditions can be applied to restrict the join (such as discriminator).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SQLJoin.JoinType

Field Summary

Fields

Modifier and Type	Field	Description
private BooleanExpression	condition	Optional condition for the join.
private SQLTable	sourceTable	The current table that we are joining from to introduce this table.
private SQLJoin	subJoin	Optional sub-join, for when we have JOIN grouping.
private SQLTable	targetTable	Table we are joining to.
private SQLJoin.JoinType	type	Type of join to perform.

Constructor Summary

Constructors

Constructor	Description
SQLJoin(SQLJoin.JoinType type, SQLTable targetTbl, SQLTable sourceTbl, BooleanExpression condition)	Constructor for a join.

Method Summary

Modifier and Type	Method	Description
void	addAndCondition(BooleanExpression expr)	Method to update the join "condition" to AND the provided expression.
BooleanExpression	getCondition()	Accessor for the conditions of the join.
static SQLJoin.JoinType	getJoinTypeForJoinExpressionType(org.datanucleus.store.query.expression.JoinExpression.JoinType ejt)
SQLTable	getSourceTable()	Accessor for the table we are joining from.
SQLJoin	getSubJoin()
SQLTable	getTargetTable()	Accessor for the table we are joining to.
SQLJoin.JoinType	getType()
void	setSubJoin(SQLJoin join)
void	setType(SQLJoin.JoinType type)
SQLText	toSQLText(DatastoreAdapter dba, boolean lock)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

type

private SQLJoin.JoinType type

Type of join to perform.

targetTable

private SQLTable targetTable

Table we are joining to. This is always set irrespective the type of join.

sourceTable

private SQLTable sourceTable

The current table that we are joining from to introduce this table.

condition

private BooleanExpression condition

Optional condition for the join.

subJoin

private SQLJoin subJoin

Optional sub-join, for when we have JOIN grouping.

Constructor Detail

SQLJoin

public SQLJoin(SQLJoin.JoinType type,
               SQLTable targetTbl,
               SQLTable sourceTbl,
               BooleanExpression condition)

Constructor for a join.

Parameters:

type - Type of join (one of the defined types in this class).

targetTbl - Target table that we are joining to

sourceTbl - Table we are joining from

condition - Join condition

Method Detail

getType

public SQLJoin.JoinType getType()

setType

public void setType(SQLJoin.JoinType type)

getTargetTable

public SQLTable getTargetTable()

Accessor for the table we are joining to.

Returns:

The table joined to

getSourceTable

public SQLTable getSourceTable()

Accessor for the table we are joining from.

Returns:

The table we join from to bring in this other table

getCondition

public BooleanExpression getCondition()

Accessor for the conditions of the join. These conditions can include

Returns:

The conditions

addAndCondition

public void addAndCondition(BooleanExpression expr)

Method to update the join "condition" to AND the provided expression.

Parameters:

expr - The expression to add to the join "condition"

setSubJoin

public void setSubJoin(SQLJoin join)

getSubJoin

public SQLJoin getSubJoin()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

toSQLText

public SQLText toSQLText(DatastoreAdapter dba,
                         boolean lock)

getJoinTypeForJoinExpressionType

public static SQLJoin.JoinType getJoinTypeForJoinExpressionType(org.datanucleus.store.query.expression.JoinExpression.JoinType ejt)