Package org.h2.expression.condition
Class SimplePredicate
- java.lang.Object
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- org.h2.expression.Expression
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- org.h2.expression.condition.Condition
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- org.h2.expression.condition.SimplePredicate
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- Direct Known Subclasses:
BooleanTest
,NullPredicate
,TypePredicate
public abstract class SimplePredicate extends Condition
Base class for simple predicates.
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Field Summary
Fields Modifier and Type Field Description (package private) Expression
left
The left hand side of the expression.(package private) boolean
not
Whether it is a "not" condition (e.g.(package private) boolean
whenOperand
Where this is the when operand of the simple case.-
Fields inherited from class org.h2.expression.Expression
AUTO_PARENTHESES, MAP_IN_AGGREGATE, MAP_IN_WINDOW, MAP_INITIAL, WITH_PARENTHESES, WITHOUT_PARENTHESES
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Fields inherited from interface org.h2.util.HasSQL
ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS
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Constructor Summary
Constructors Constructor Description SimplePredicate(Expression left, boolean not, boolean whenOperand)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
getCost()
Estimate the cost to process the expression.Expression
getSubexpression(int index)
Returns subexpression with specified index.int
getSubexpressionCount()
Returns count of subexpressions.boolean
isEverything(ExpressionVisitor visitor)
Check if this expression and all sub-expressions can fulfill a criteria.boolean
isWhenConditionOperand()
Returns whether this expression is a right side of condition in a when operand.void
mapColumns(ColumnResolver resolver, int level, int state)
Map the columns of the resolver to expression columns.boolean
needParentheses()
Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.Expression
optimize(SessionLocal session)
Try to optimize the expression.void
setEvaluatable(TableFilter tableFilter, boolean b)
Tell the expression columns whether the table filter can return values now.void
updateAggregate(SessionLocal session, int stage)
Update an aggregate value.-
Methods inherited from class org.h2.expression.condition.Condition
castToBoolean, getType
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Methods inherited from class org.h2.expression.Expression
addFilterConditions, createIndexConditions, getAlias, getBooleanValue, getColumnName, getColumnNameForView, getEnclosedSQL, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getSQL, getSQL, getSQL, getSQL, getTableAlias, getTableName, getUnenclosedSQL, getValue, getWhenSQL, getWhenValue, isConstant, isIdentity, isNullConstant, isValueSet, optimizeCondition, toString, writeExpressions, writeExpressions
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.h2.util.HasSQL
getTraceSQL
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Field Detail
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left
Expression left
The left hand side of the expression.
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not
final boolean not
Whether it is a "not" condition (e.g. "is not null").
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whenOperand
final boolean whenOperand
Where this is the when operand of the simple case.
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Constructor Detail
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SimplePredicate
SimplePredicate(Expression left, boolean not, boolean whenOperand)
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Method Detail
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optimize
public Expression optimize(SessionLocal session)
Description copied from class:Expression
Try to optimize the expression.- Specified by:
optimize
in classExpression
- Parameters:
session
- the session- Returns:
- the optimized expression
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setEvaluatable
public void setEvaluatable(TableFilter tableFilter, boolean b)
Description copied from class:Expression
Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.- Specified by:
setEvaluatable
in classExpression
- Parameters:
tableFilter
- the table filterb
- true if the table filter can return value
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needParentheses
public final boolean needParentheses()
Description copied from class:Expression
Returns whether this expressions needs to be wrapped in parentheses when it is used as an argument of other expressions.- Overrides:
needParentheses
in classExpression
- Returns:
true
if it is
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updateAggregate
public void updateAggregate(SessionLocal session, int stage)
Description copied from class:Expression
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.- Specified by:
updateAggregate
in classExpression
- Parameters:
session
- the sessionstage
- select stage
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mapColumns
public void mapColumns(ColumnResolver resolver, int level, int state)
Description copied from class:Expression
Map the columns of the resolver to expression columns.- Specified by:
mapColumns
in classExpression
- Parameters:
resolver
- the column resolverlevel
- the subquery nesting levelstate
- current state for nesting checks, initial value isExpression.MAP_INITIAL
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isEverything
public boolean isEverything(ExpressionVisitor visitor)
Description copied from class:Expression
Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.- Specified by:
isEverything
in classExpression
- Parameters:
visitor
- the visitor- Returns:
- if the criteria can be fulfilled
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getCost
public int getCost()
Description copied from class:Expression
Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.- Specified by:
getCost
in classExpression
- Returns:
- the estimated cost
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getSubexpressionCount
public int getSubexpressionCount()
Description copied from class:Expression
Returns count of subexpressions.- Overrides:
getSubexpressionCount
in classExpression
- Returns:
- count of subexpressions
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getSubexpression
public Expression getSubexpression(int index)
Description copied from class:Expression
Returns subexpression with specified index.- Overrides:
getSubexpression
in classExpression
- Parameters:
index
- 0-based index- Returns:
- subexpression with specified index, may be null
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isWhenConditionOperand
public final boolean isWhenConditionOperand()
Description copied from class:Expression
Returns whether this expression is a right side of condition in a when operand.- Overrides:
isWhenConditionOperand
in classExpression
- Returns:
true
if it is,false
otherwise
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