org.datanucleus.store.rdbms.sql.expression

Class NullLiteral

java.lang.Object

org.datanucleus.store.rdbms.sql.expression.SQLExpression

org.datanucleus.store.rdbms.sql.expression.NullLiteral

All Implemented Interfaces:

SQLLiteral

public class NullLiteral
extends SQLExpression
implements SQLLiteral

Representation of a Null literal in a Query.

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

SQLExpression.ColumnExpressionList

Field Summary

Fields inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

lowestOperator, mapping, parameterName, st, stmt, subExprs, table

Constructor Summary

Constructors

Constructor and Description
NullLiteral(SQLStatement stmt, JavaTypeMapping mapping, Object value, String parameterName) Constructor for a null literal with a value (i.e null!).

Method Summary

Modifier and Type	Method and Description
SQLExpression	add(SQLExpression expr) Additive Operator.
BooleanExpression	eq(SQLExpression expr) Equality operator (equals to)
Object	getValue() Accessor to the literal value
BooleanExpression	ne(SQLExpression expr) Not equality operator (not equals to)
void	setNotParameter() Method to set this literal as not being a parameter.

Methods inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

and, cast, com, distinct, div, encloseInParentheses, eor, ge, getJavaTypeMapping, getLowestOperator, getNumberOfSubExpressions, getParameterName, getSQLStatement, getSQLTable, getSubExpression, gt, in, invoke, ior, is, isParameter, le, lt, mod, mul, neg, not, setJavaTypeMapping, sub, toSQLText

Methods inherited from class java.lang.Object

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

Constructor Detail

NullLiteral

public NullLiteral(SQLStatement stmt,
                   JavaTypeMapping mapping,
                   Object value,
                   String parameterName)

Constructor for a null literal with a value (i.e null!).

Parameters:

stmt - the SQL statement

mapping - the mapping

value - Null!

parameterName - Name of the parameter that this represents if any (JDBC "?") NOT USED

Method Detail

getValue

public Object getValue()

Description copied from interface: SQLLiteral

Accessor to the literal value

Specified by:

getValue in interface SQLLiteral

Returns:

the value of the literal

add

public SQLExpression add(SQLExpression expr)

Description copied from class: SQLExpression

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 SQLExpression

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(SQLExpression expr)

Description copied from class: SQLExpression

Equality operator (equals to)

Overrides:

eq in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

The type of an equality expression is a boolean

ne

public BooleanExpression ne(SQLExpression expr)

Description copied from class: SQLExpression

Not equality operator (not equals to)

Overrides:

ne in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

The type of an equality expression is a boolean

setNotParameter

public void setNotParameter()

Description copied from interface: SQLLiteral

Method to set this literal as not being a parameter. If the literal if not currently a parameter then does nothing. Updates any underlying SQL to have the value.

Specified by:

setNotParameter in interface SQLLiteral