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

java.lang.Object
  extended by org.datanucleus.store.rdbms.sql.expression.SQLExpression
      extended by 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
isParameter, LOCALISER, lowestOperator, mapping, st, stmt, subExprs, table
 
Constructor Summary
NullLiteral(SQLStatement stmt, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping, java.lang.Object value, boolean parameter)
          Constructor for a null literal with a value (i.e null!).
 
Method Summary
 SQLExpression add(SQLExpression expr)
          Additive Operator.
 BooleanExpression eq(SQLExpression expr)
          Equality operator (equals to)
 java.lang.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, checkForAndCorrectParameterComparison, com, div, encloseInParentheses, eor, ge, getJavaTypeMapping, getNumberOfSubExpressions, getSQLStatement, getSQLTable, gt, in, invoke, ior, is, isParameter, le, lt, mod, mul, neg, not, 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,
                   org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping,
                   java.lang.Object value,
                   boolean parameter)
Constructor for a null literal with a value (i.e null!).

Parameters:
stmt - the SQL statement
mapping - the mapping
value - Null!
parameter - Whether this is treated as a parameter (JDBC "?") NOT USED
Method Detail

getValue

public java.lang.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


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