ClassExpression

java.lang.Object
- org.datanucleus.store.query.expression.Expression
- - org.datanucleus.store.query.expression.ClassExpression

All Implemented Interfaces:

java.io.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 org.datanucleus.store.query.expression.Expression
  Expression.DyadicOperator, Expression.MonadicOperator, Expression.Operator

Field Summary

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

Fields inherited from class org.datanucleus.store.query.expression.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(java.lang.String alias)

Method Summary

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

Methods inherited from class org.datanucleus.store.query.expression.Expression
evaluate, getLeft, getOperator, getParent, getRight, getSymbol, setAlias, setLeft, setRight

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - serialVersionUID
```
private static final long serialVersionUID
```
    See Also:
    
    Constant Field Values
  - candidateExpression
```
java.lang.String candidateExpression
```
    Optional candidate expression when in subquery and the class is a relation to the outer query.
- Constructor Detail
  - ClassExpression
```
public ClassExpression(java.lang.String alias)
```
- Method Detail
  - setCandidateExpression
```
public void setCandidateExpression(java.lang.String expr)
```
  - getCandidateExpression
```
public java.lang.String getCandidateExpression()
```
  - setJoinExpression
```
public void setJoinExpression(JoinExpression expr)
```
    Set the right expression to the provided join.
    
    Parameters:
    
    expr - Join information
  - getAlias
```
public java.lang.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 java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object