Top Description Fields Constructors Methods
org.h2.expression.condition

public abstract Class SimplePredicate

extends Condition
Class Inheritance
Known Direct Subclasses
org.h2.expression.condition.TypePredicate, org.h2.expression.condition.BooleanTest, org.h2.expression.condition.NullPredicate
Imports
org.h2.engine.SessionLocal, org.h2.expression.Expression, .ExpressionVisitor, .ValueExpression, org.h2.table.ColumnResolver, .TableFilter
Base class for simple predicates.

Field Summary

Modifier and TypeField and Description
pack-priv Expression
left

The left hand side of the expression.

pack-priv final boolean
not

Whether it is a "not" condition (e.g. "is not null").

pack-priv final boolean
whenOperand

Where this is the when operand of the simple case.

Constructor Summary

AccessConstructor and Description
pack-priv
SimplePredicate(Expression left, boolean not, boolean whenOperand)

Method Summary

Modifier and TypeMethod and Description
public int
getCost()

Implements abstract org.h2.expression.Expression.getCost.

Estimate the cost to process the expression.

public Expression
getSubexpression(int
0-based index
index)

Overrides org.h2.expression.Expression.getSubexpression.

Returns subexpression with specified index.

public int
getSubexpressionCount()

Overrides org.h2.expression.Expression.getSubexpressionCount.

Returns count of subexpressions.

public boolean
isEverything(ExpressionVisitor
the visitor
visitor)

Implements abstract org.h2.expression.Expression.isEverything.

Check if this expression and all sub-expressions can fulfill a criteria.

public final boolean
isWhenConditionOperand()

Overrides org.h2.expression.Expression.isWhenConditionOperand.

Returns whether this expression is a right side of condition in a when operand.

public void
mapColumns(ColumnResolver
the column resolver
resolver, int
the subquery nesting level
level, int
current state for nesting checks, initial value is MAP_INITIAL
state)

Implements abstract org.h2.expression.Expression.mapColumns.

Map the columns of the resolver to expression columns.

public final boolean
needParentheses()

Overrides org.h2.expression.Expression.needParentheses.

Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.

public Expression
optimize(SessionLocal
the session
session)

Implements abstract org.h2.expression.Expression.optimize.

Try to optimize the expression.

public void
setEvaluatable(TableFilter
the table filter
tableFilter, boolean
true if the table filter can return value
b)

Implements abstract org.h2.expression.Expression.setEvaluatable.

Tell the expression columns whether the table filter can return values now.

public void
updateAggregate(SessionLocal
the session
session, int
select stage
stage)

Implements abstract org.h2.expression.Expression.updateAggregate.

Update an aggregate value.

Inherited from org.h2.expression.condition.Condition:
castToBooleangetType

Field Detail

leftback to summary
pack-priv Expression left

The left hand side of the expression.

notback to summary
pack-priv final boolean not

Whether it is a "not" condition (e.g. "is not null").

whenOperandback to summary
pack-priv final boolean whenOperand

Where this is the when operand of the simple case.

Constructor Detail

SimplePredicateback to summary
pack-priv SimplePredicate(Expression left, boolean not, boolean whenOperand)

Method Detail

getCostback to summary
public int getCost()

Implements abstract org.h2.expression.Expression.getCost.

Doc from org.h2.expression.Expression.getCost.

Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.

Returns:int

the estimated cost

Annotations
@Override
getSubexpressionback to summary
public Expression getSubexpression(int index)

Overrides org.h2.expression.Expression.getSubexpression.

Doc from org.h2.expression.Expression.getSubexpression.

Returns subexpression with specified index.

Parameters
index:int

0-based index

Returns:Expression

subexpression with specified index, may be null

Annotations
@Override
getSubexpressionCountback to summary
public int getSubexpressionCount()

Overrides org.h2.expression.Expression.getSubexpressionCount.

Doc from org.h2.expression.Expression.getSubexpressionCount.

Returns count of subexpressions.

Returns:int

count of subexpressions

Annotations
@Override
isEverythingback to summary
public boolean isEverything(ExpressionVisitor visitor)

Implements abstract org.h2.expression.Expression.isEverything.

Doc from org.h2.expression.Expression.isEverything.

Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.

Parameters
visitor:ExpressionVisitor

the visitor

Returns:boolean

if the criteria can be fulfilled

Annotations
@Override
isWhenConditionOperandback to summary
public final boolean isWhenConditionOperand()

Overrides org.h2.expression.Expression.isWhenConditionOperand.

Doc from org.h2.expression.Expression.isWhenConditionOperand.

Returns whether this expression is a right side of condition in a when operand.

Returns:boolean

true if it is, false otherwise

Annotations
@Override
mapColumnsback to summary
public void mapColumns(ColumnResolver resolver, int level, int state)

Implements abstract org.h2.expression.Expression.mapColumns.

Doc from org.h2.expression.Expression.mapColumns.

Map the columns of the resolver to expression columns.

Parameters
resolver:ColumnResolver

the column resolver

level:int

the subquery nesting level

state:int

current state for nesting checks, initial value is MAP_INITIAL

Annotations
@Override
needParenthesesback to summary
public final boolean needParentheses()

Overrides org.h2.expression.Expression.needParentheses.

Doc from org.h2.expression.Expression.needParentheses.

Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.

Returns:boolean

true if it is

Annotations
@Override
optimizeback to summary
public Expression optimize(SessionLocal session)

Implements abstract org.h2.expression.Expression.optimize.

Doc from org.h2.expression.Expression.optimize.

Try to optimize the expression.

Parameters
session:SessionLocal

the session

Returns:Expression

the optimized expression

Annotations
@Override
setEvaluatableback to summary
public void setEvaluatable(TableFilter tableFilter, boolean b)

Implements abstract org.h2.expression.Expression.setEvaluatable.

Doc from org.h2.expression.Expression.setEvaluatable.

Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.

Parameters
tableFilter:TableFilter

the table filter

b:boolean

true if the table filter can return value

Annotations
@Override
updateAggregateback to summary
public void updateAggregate(SessionLocal session, int stage)

Implements abstract org.h2.expression.Expression.updateAggregate.

Doc from org.h2.expression.Expression.updateAggregate.

Update an aggregate value. This method is called at statement execution time. It is usually called once for each row, but if the expression is used multiple times (for example in the column list, and as part of the HAVING expression) it is called multiple times - the row counter needs to be used to make sure the internal state is only updated once.

Parameters
session:SessionLocal

the session

stage:int

select stage

Annotations
@Override