org.datanucleus.query.expression
Class JoinExpression

java.lang.Object
  org.datanucleus.query.expression.Expression
      org.datanucleus.query.expression.JoinExpression

public class JoinExpression
extends Expression

Expression representing a join between a candidate class, and the class of a field of the first class. An example is in JPQL where we have a "from" clause like

SELECT ... FROM Product p JOIN p.reviews r

so the join between "Product p" and "Review r" using "p.reviews". Can have a JoinExpression to its right.

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.query.expression.Expression

Expression.DyadicOperator, Expression.MonadicOperator, Expression.Operator

Field Summary

static int	JOIN_INNER
static int	JOIN_INNER_FETCH
static int	JOIN_OUTER
static int	JOIN_OUTER_FETCH

Fields inherited from class org.datanucleus.query.expression.Expression

left, LOCALISER, lowestOperator, op, OP_ADD, OP_AND, OP_BETWEEN, OP_COM, OP_CONCAT, OP_DISTINCT, OP_DIV, OP_EQ, OP_GT, OP_GTEQ, OP_IN, OP_IS, OP_ISNOT, OP_LIKE, OP_LT, OP_LTEQ, OP_MOD, OP_MUL, OP_NEG, OP_NOT, OP_NOTEQ, OP_OR, OP_SUB, right, symbol

Constructor Summary

JoinExpression(SymbolTable symtbl, PrimaryExpression expr, java.lang.String alias, int type)

Method Summary

Symbol	bind()
java.lang.Object	evaluate(ExpressionEvaluator eval)
java.lang.String	getAlias()
PrimaryExpression	getPrimaryExpression()
int	getType()
void	setJoinExpression(JoinExpression expr)

Methods inherited from class org.datanucleus.query.expression.Expression

getLeft, getOperator, getRight, getSymbol

Methods inherited from class java.lang.Object

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

Field Detail

JOIN_INNER

public static final int JOIN_INNER

See Also:

Constant Field Values

JOIN_OUTER

public static final int JOIN_OUTER

See Also:

Constant Field Values

JOIN_INNER_FETCH

public static final int JOIN_INNER_FETCH

See Also:

Constant Field Values

JOIN_OUTER_FETCH

public static final int JOIN_OUTER_FETCH

See Also:

Constant Field Values

Constructor Detail

JoinExpression

public JoinExpression(SymbolTable symtbl,
                      PrimaryExpression expr,
                      java.lang.String alias,
                      int type)

Method Detail

evaluate

public java.lang.Object evaluate(ExpressionEvaluator eval)

Specified by:

evaluate in class Expression

setJoinExpression

public void setJoinExpression(JoinExpression expr)

getPrimaryExpression

public PrimaryExpression getPrimaryExpression()

getAlias

public java.lang.String getAlias()

getType

public int getType()

bind

public Symbol bind()

Specified by:

bind in class Expression