org.datanucleus.store.mapped.expression
Class NullLiteral

java.lang.Object
  extended by org.datanucleus.store.mapped.expression.ScalarExpression
      extended by org.datanucleus.store.mapped.expression.NullLiteral
All Implemented Interfaces:
Literal
Direct Known Subclasses:
UnknownLiteral

public class NullLiteral
extends ScalarExpression
implements Literal

Representation of a Null literal in a Query.


Nested Class Summary
 
Nested classes/interfaces inherited from class org.datanucleus.store.mapped.expression.ScalarExpression
ScalarExpression.DatastoreFieldExpression, ScalarExpression.DyadicOperator, ScalarExpression.ExpressionList, ScalarExpression.IllegalArgumentTypeException, ScalarExpression.IllegalOperationException, ScalarExpression.MethodInvocationException, ScalarExpression.MonadicOperator, ScalarExpression.Operator
 
Field Summary
 
Fields inherited from class org.datanucleus.store.mapped.expression.ScalarExpression
aliasIdentifier, checkForTypeAssignability, expressionList, FILTER, LOCALISER, lowestOperator, mapping, OP_ADD, OP_AND, OP_BETWEEN, OP_COM, OP_CONCAT, 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_NOTLIKE, OP_OR, OP_SUB, parameterName, PROJECTION, qs, st, te
 
Constructor Summary
NullLiteral(QueryExpression qs)
          Creates a null literal
 
Method Summary
 ScalarExpression add(ScalarExpression expr)
          Additive Operator.
 BooleanExpression eq(ScalarExpression expr)
          Equality operator (equals to)
 java.lang.Object getRawValue()
          Accessor for the "raw" value that this literal represents.
 java.lang.Object getValue()
          Accessor to the literal value
 BooleanExpression noteq(ScalarExpression expr)
          Equality operator (not equals to)
 void setRawValue(java.lang.Object val)
          Method to save a "raw" value that this literal represents.
 
Methods inherited from class org.datanucleus.store.mapped.expression.ScalarExpression
accessField, and, as, assertValidTypeForParameterComparison, callMethod, cast, checkForTypeAssignability, com, div, encloseWithInParentheses, eor, equals, getAlias, getConsistentTypeForParameterComparison, getExpressionList, getLogicSetExpression, getMapping, getNonAliasExpression, getQueryExpression, gt, gteq, in, instanceOf, ior, lt, lteq, mod, mul, neg, not, setParameterName, sub, toStatementText, toString
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

NullLiteral

public NullLiteral(QueryExpression qs)
Creates a null literal

Parameters:
qs - the QueryExpression
Method Detail

getValue

public java.lang.Object getValue()
Description copied from interface: Literal
Accessor to the literal value

Specified by:
getValue in interface Literal
Returns:
the value of the literal

add

public ScalarExpression add(ScalarExpression expr)
Description copied from class: ScalarExpression
Additive Operator. The binary + operator performs addition when applied to two operands of numeric type, producing the sum of the operands. If the type of either operand of a + operator is String, then the operation is string concatenation.

Overrides:
add in class ScalarExpression
Parameters:
expr - the right-hand operand
Returns:
If one of the operands is String, the returned value is the string concatenation; The sum of two operands of numeric type. The left-hand operand is the minuend and the right-hand operand is the subtrahend;

eq

public BooleanExpression eq(ScalarExpression expr)
Description copied from class: ScalarExpression
Equality operator (equals to)

Overrides:
eq in class ScalarExpression
Parameters:
expr - the right-hand operand
Returns:
The type of an equality expression is a boolean

noteq

public BooleanExpression noteq(ScalarExpression expr)
Description copied from class: ScalarExpression
Equality operator (not equals to)

Overrides:
noteq in class ScalarExpression
Parameters:
expr - the right-hand operand
Returns:
The type of an equality expression is a boolean

setRawValue

public void setRawValue(java.lang.Object val)
Method to save a "raw" value that this literal represents. This value differs from the literal value since that is of the same type as this literal.

Specified by:
setRawValue in interface Literal
Parameters:
val - The raw value

getRawValue

public java.lang.Object getRawValue()
Accessor for the "raw" value that this literal represents. This value differs from the literal value since that is of the same type as this literal.

Specified by:
getRawValue in interface Literal
Returns:
The raw value


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