Class ClassExpression

java.lang.Object

org.datanucleus.store.query.expression.Expression

org.datanucleus.store.query.expression.ClassExpression

All Implemented Interfaces:

Serializable

public class ClassExpression
extends Expression

Expression representing a candidate in a FROM clause. This is used in JPQL where we have a "from" clause like

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

so the ClassExpression is for alias "p" of type Product. The class name is stored in the Symbol, keyed by this alias. Can have a JoinExpression to its right.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class Expression

Expression.DyadicOperator, Expression.MonadicOperator, Expression.Operator

Field Summary

Fields

Modifier and Type	Field	Description
(package private) String	candidateExpression	Optional candidate expression when in subquery and the class is a relation to the outer query.
private static final long	serialVersionUID

Fields inherited from class Expression

alias, left, op, OP_ADD, OP_AND, OP_BIT_AND, OP_BIT_OR, OP_BIT_XOR, OP_CAST, 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_NOTIN, OP_OR, OP_SUB, parent, right, symbol

Constructor Summary

Constructors

Constructor	Description
ClassExpression(String alias)

Method Summary

Modifier and Type	Method	Description
Symbol	bind(SymbolTable symtbl)	Method to bind the expression to the symbol table as appropriate.
String	getAlias()
String	getCandidateExpression()
void	setCandidateExpression(String expr)
void	setJoinExpression(JoinExpression expr)	Set the right expression to the provided join.
String	toString()

Methods inherited from class Expression

evaluate, getLeft, getOperator, getParent, getRight, getSymbol, setAlias, setLeft, setRight

Methods inherited from class Object

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

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

candidateExpression

String candidateExpression

Optional candidate expression when in subquery and the class is a relation to the outer query.

Constructor Details

ClassExpression

public ClassExpression(String alias)

Method Details

setCandidateExpression

public void setCandidateExpression(String expr)

getCandidateExpression

public String getCandidateExpression()

setJoinExpression

public void setJoinExpression(JoinExpression expr)

Set the right expression to the provided join.

Parameters:

expr - Join information

getAlias

public String getAlias()

Overrides:

getAlias in class Expression

bind

public Symbol bind(SymbolTable symtbl)

Method to bind the expression to the symbol table as appropriate.

Specified by:

bind in class Expression

Parameters:

symtbl - Symbol table

Returns:

The symbol for this expression

toString

public String toString()

Overrides:

toString in class Object