com.triactive.jdo.store.sql.expr
Class SimulatedBooleanColumnExpression

java.lang.Object
  com.triactive.jdo.store.sql.expr.AbstractSqlExpression
      com.triactive.jdo.store.sql.expr.BooleanExpression
          com.triactive.jdo.store.sql.expr.ComparisonExpression
              com.triactive.jdo.store.sql.expr.SimulatedBooleanColumnExpression

All Implemented Interfaces:

SqlExpression, StatementTextGenerator

Direct Known Subclasses:

BooleanBitColumnExpression, BooleanCharColumnExpression

public abstract class SimulatedBooleanColumnExpression

extends com.triactive.jdo.store.sql.expr.ComparisonExpression

A boolean SQL expression referencing a database column that is treated as a boolean but whose real SQL type is not boolean.

The column is restricted to one of two values used to represent true and false. When referencing the column we construct a larger expression that compares the column with one of those two values. The database effectively treats the comparison as boolean, at least in certain contexts such as a WHERE clause.

Author:

Mike Martin

Nested Class Summary

Nested classes inherited from class com.triactive.jdo.store.sql.expr.AbstractSqlExpression

AbstractSqlExpression.Body, AbstractSqlExpression.CompoundExpression, AbstractSqlExpression.SimpleColumnReference, AbstractSqlExpression.SubqueryExpression

Field Summary

protected SqlExpression	qscExpr
protected boolean	truthTest

Fields inherited from class com.triactive.jdo.store.sql.expr.AbstractSqlExpression

body, qs

Constructor Summary

protected

SimulatedBooleanColumnExpression(SqlExpression qscExpr, boolean truthTest, SqlExpression falseValue)

Method Summary

BooleanExpression	eq(SqlExpression expr) Returns a new expression representing "this == expr".
boolean	getTruthTest() Represents the sense of the boolean expression.
SqlExpression	getUnderlyingColumn() Returns an SQL expression representing an unadorned reference to the underlying non-boolean column.
BooleanExpression	not()
BooleanExpression	noteq(SqlExpression expr) Returns a new expression representing "this != expr".
int	select() Adds this expression to the list of those SELECTed in its surrounding query statement.

Methods inherited from class com.triactive.jdo.store.sql.expr.BooleanExpression

and, eor, ior, protectOuterJoins, unprotectedOuterJoins, unprotectedOuterJoins

Methods inherited from class com.triactive.jdo.store.sql.expr.AbstractSqlExpression

accessField, add, callMethod, cast, com, div, getColumnMapping, getJavaType, getMapping, getQueryStatement, getReferencedColumns, gt, gteq, innermostQuery, innermostQuery, lt, lteq, mod, mul, neg, newBody, newBody, newBody, newBody, newBody, newBody, newResultExpression, newSubqueryBody, setMapping, sub, toStatementText, toString

Methods inherited from class java.lang.Object

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

Field Detail

qscExpr

protected final SqlExpression qscExpr

truthTest

protected final boolean truthTest

Constructor Detail

SimulatedBooleanColumnExpression

protected SimulatedBooleanColumnExpression(SqlExpression qscExpr,
                                           boolean truthTest,
                                           SqlExpression falseValue)

Method Detail

getUnderlyingColumn

public SqlExpression getUnderlyingColumn()

Returns an SQL expression representing an unadorned reference to the underlying non-boolean column.

getTruthTest

public final boolean getTruthTest()

Represents the sense of the boolean expression.

Returns:

true if testing the column for boolean true, false if testing it for false (e.g. if the expression has been negated).

select

public int select()

Description copied from interface: SqlExpression

Adds this expression to the list of those SELECTed in its surrounding query statement.

Specified by:

select in interface SqlExpression

Overrides:

select in class AbstractSqlExpression

eq

public BooleanExpression eq(SqlExpression expr)

Description copied from interface: SqlExpression

Returns a new expression representing "this == expr".

Specified by:

eq in interface SqlExpression

Overrides:

eq in class BooleanExpression

noteq

public BooleanExpression noteq(SqlExpression expr)

Description copied from interface: SqlExpression

Returns a new expression representing "this != expr".

Specified by:

noteq in interface SqlExpression

Overrides:

noteq in class BooleanExpression

not

public BooleanExpression not()

Specified by:

not in interface SqlExpression

Overrides:

not in class BooleanExpression