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

java.lang.Object
  org.datanucleus.store.rdbms.sql.expression.SQLExpression
      org.datanucleus.store.rdbms.sql.expression.BooleanExpression

Direct Known Subclasses:

BooleanLiteral, BooleanSubqueryExpression, InExpression

public class BooleanExpression
extends SQLExpression

Representation of a Boolean expression in a Query. Can be represented in one of the following ways in the datastore

• As String-based, so stored as "Y", "N"
• As numeric-based, so stored as 1, 0
• As boolean-based, so stored as true, false

A boolean expression has "closure" if it represents a boolean SQL expression (i.e "fld == val"). If it doesn't have "closure" then it represents a clause like "booleanFld" or "false" or "true".

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

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

Constructor Summary

BooleanExpression(org.datanucleus.query.expression.Expression.MonadicOperator op, SQLExpression expr1)
Perform an operation

BooleanExpression(SQLExpression expr1, org.datanucleus.query.expression.Expression.DyadicOperator op, SQLExpression expr2)
Perform an operation

BooleanExpression(SQLStatement stmt, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)
Constructor for a boolean expression for the specified mapping of the table.

BooleanExpression(SQLStatement stmt, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping, String sql)
Constructor for a boolean expression for the specified mapping using the specified SQL text.

BooleanExpression(SQLStatement stmt, SQLTable table, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)
Constructor for a boolean expression for the specified mapping of the table.

Method Summary

BooleanExpression	and(SQLExpression expr) Conditional And.
BooleanExpression	eor(SQLExpression expr) Exclusive OR
BooleanExpression	eq(SQLExpression expr) Equality operator (equals to)
boolean	hasClosure()
BooleanExpression	in(SQLExpression expr, boolean not) In expression.
SQLExpression	invoke(String methodName, List args) Invocation of a method on this expression.
BooleanExpression	ior(SQLExpression expr) Conditional OR.
BooleanExpression	ne(SQLExpression expr) Not equality operator (not equals to)
BooleanExpression	neg() Unary Minus Operator
BooleanExpression	not() Logical complement

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

add, cast, com, distinct, div, encloseInParentheses, ge, getJavaTypeMapping, getLowestOperator, getNumberOfSubExpressions, getParameterName, getSQLStatement, getSQLTable, getSubExpression, gt, is, isParameter, le, lt, mod, mul, setJavaTypeMapping, sub, toSQLText

Methods inherited from class java.lang.Object

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

Constructor Detail

BooleanExpression

public BooleanExpression(SQLStatement stmt,
                         org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping,
                         String sql)

Constructor for a boolean expression for the specified mapping using the specified SQL text.

Parameters:

stmt - The statement

mapping - the mapping associated to this expression

sql - The SQL text that will return a boolean

BooleanExpression

public BooleanExpression(SQLStatement stmt,
                         SQLTable table,
                         org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)

Constructor for a boolean expression for the specified mapping of the table. The boolean expression DOESN'T have closure using this constructor.

Parameters:

stmt - The statement

table - The table this mapping belongs to

mapping - the mapping associated to this expression

BooleanExpression

public BooleanExpression(SQLStatement stmt,
                         org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)

Constructor for a boolean expression for the specified mapping of the table. The boolean expression has closure using this constructor.

Parameters:

stmt - The statement

mapping - the mapping associated to this expression

BooleanExpression

public BooleanExpression(org.datanucleus.query.expression.Expression.MonadicOperator op,
                         SQLExpression expr1)

Perform an operation

op

on expression

expr1

. The boolean expression has closure using this constructor.

Parameters:

op - operator

expr1 - operand

BooleanExpression

public BooleanExpression(SQLExpression expr1,
                         org.datanucleus.query.expression.Expression.DyadicOperator op,
                         SQLExpression expr2)

Perform an operation

op

between

expr1

and

expr2

. The boolean expression has closure using this constructor.

Parameters:

expr1 - the first expression

op - the operator between operands

expr2 - the second expression

Method Detail

hasClosure

public boolean hasClosure()

and

public BooleanExpression and(SQLExpression expr)

Description copied from class: SQLExpression

Conditional And. Evaluates its right-hand operand only if the value of its left-hand operand is true.

Overrides:

and in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

the result value is true if both operand values are true; otherwise, the result is false.

eor

public BooleanExpression eor(SQLExpression expr)

Description copied from class: SQLExpression

Exclusive OR

Overrides:

eor in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

the result value is the bitwise exclusive OR of the operand values.

ior

public BooleanExpression ior(SQLExpression expr)

Description copied from class: SQLExpression

Conditional OR. Evaluates its right-hand operand only if the value of its left-hand operand is false.

Overrides:

ior in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

the result value is false if both operand values are false; otherwise, the result is true.

not

public BooleanExpression not()

Description copied from class: SQLExpression

Logical complement

Overrides:

not in class SQLExpression

Returns:

the result value is false if operand is true; otherwise, the result is true.

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

in

public BooleanExpression in(SQLExpression expr,
                            boolean not)

Description copied from class: SQLExpression

In expression. Return true if this is contained by expr

Overrides:

in in class SQLExpression

Parameters:

expr - the right-hand expression

not - Whether we really want "not in"

Returns:

true if the left-hand expression is contained by the right-hand expression. Otherwise the result is false.

invoke

public SQLExpression invoke(String methodName,
                            List args)

Description copied from class: SQLExpression

Invocation of a method on this expression.

Overrides:

invoke in class SQLExpression

Parameters:

methodName - name of the method to invoke

args - Args to this method (if any)

Returns:

the converted value

neg

public BooleanExpression neg()

Description copied from class: SQLExpression

Unary Minus Operator

Overrides:

neg in class SQLExpression

Returns:

the type of the unary minus expression is the promoted type of the operand.