Class SimpleSelectClauseStateObject
java.lang.Object
org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractStateObject
org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractSelectClauseStateObject
org.eclipse.persistence.jpa.jpql.tools.model.query.SimpleSelectClauseStateObject
- All Implemented Interfaces:
StateObject
The SELECT statement queries data from entities. This version simply does not handle
OBJECT and NEW identifiers. It is used from within another expression.
BNF: simple_select_clause ::= SELECT [DISTINCT] simple_select_expression
- Since:
- 2.4
- Version:
- 2.4
- See Also:
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Field Summary
Modifier and TypeFieldDescriptionstatic final String
Notifies the select expression property has changed.Fields inherited from class org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractSelectClauseStateObject
DISTINCT_PROPERTY
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Constructor Summary
ConstructorDescriptionCreates a newSubQuerySelectClauseStateObject
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Method Summary
Modifier and TypeMethodDescriptionvoid
accept
(StateObjectVisitor visitor) Visits thisStateObject
by the givenvisitor
.protected void
addChildren
(List<StateObject> children) Adds the children of thisStateObject
to the given list.Creates and returns a newISimpleSelectExpressionStateObjectBuilder
that can be used to programmatically create a single select expression and once the expression is complete,ISimpleSelectExpressionStateObjectBuilder.commit()
will push theStateObject
representation of that expression as this clause's select expression.Returns the actual parsed object if thisStateObject
representation of the JPQL query was created by parsing an existing JPQL query.Returns theAbstractFromClauseStateObject
representing the FROM clause.Returns the parent of thisStateObject
.Returnsboolean
Determines whether thisSELECT
clause has a select item defined (only one can be set for a subquery'sSELECT
clause and many for a top-level query).boolean
isEquivalent
(StateObject stateObject) Determines whether the givenStateObject
is equivalent to this one, i.e.void
Parses the given JPQL fragment and create the select item.void
setExpression
(SimpleSelectClause expression) Keeps a reference of theparsed object
object, which should only be done when this object is instantiated during the conversion of a parsed JPQL query intoStateObjects
.void
setSelectItem
(StateObject stateObject) Sets the givenStateObject
as this clause's select item.protected void
toTextInternal
(Appendable writer) Prints out a string representation of thisStateObject
, which should not be used to define atrue
string representation of a JPQL query but should be used for debugging purposes.Methods inherited from class org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractSelectClauseStateObject
hasDistinct, setDistinct, toggleDistinct
Methods inherited from class org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractStateObject
acceptUnknownVisitor, acceptUnknownVisitor, addProblems, addPropertyChangeListener, areEquivalent, buildProblem, buildProblem, buildStateObject, buildStateObjects, checkParent, children, decorate, equals, findIdentificationVariable, firePropertyChanged, getChangeSupport, getDeclaration, getDecorator, getGrammar, getManagedTypeProvider, getQueryBuilder, getRoot, getType, getType, getTypeHelper, getTypeRepository, hashCode, initialize, isDecorated, parent, parent, parent, removePropertyChangeListener, setExpression, setParent, toString, toString, toStringInternal, toStringItems, toText
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Field Details
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SELECT_ITEM_PROPERTY
Notifies the select expression property has changed.- See Also:
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Constructor Details
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SimpleSelectClauseStateObject
Creates a newSubQuerySelectClauseStateObject
.- Parameters:
parent
- The parent of this state object, which cannot benull
- Throws:
NullPointerException
- The given parent cannot benull
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Method Details
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accept
Description copied from interface:StateObject
Visits thisStateObject
by the givenvisitor
.- Parameters:
visitor
- Thevisitor
to visit this object
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addChildren
Description copied from class:AbstractStateObject
Adds the children of thisStateObject
to the given list.- Overrides:
addChildren
in classAbstractStateObject
- Parameters:
children
- The list used to store the children
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getBuilder
Creates and returns a newISimpleSelectExpressionStateObjectBuilder
that can be used to programmatically create a single select expression and once the expression is complete,ISimpleSelectExpressionStateObjectBuilder.commit()
will push theStateObject
representation of that expression as this clause's select expression.- Returns:
- A new builder that can be used to quickly create a select expression
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getExpression
Description copied from interface:StateObject
Returns the actual parsed object if thisStateObject
representation of the JPQL query was created by parsing an existing JPQL query.- Specified by:
getExpression
in interfaceStateObject
- Overrides:
getExpression
in classAbstractSelectClauseStateObject
- Returns:
- The parsed object when a JPQL query is parsed and converted into a
StateObject
ornull
when the JPQL query is manually created (i.e. not from a string)
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getFromClause
Description copied from class:AbstractSelectClauseStateObject
Returns theAbstractFromClauseStateObject
representing the FROM clause.- Overrides:
getFromClause
in classAbstractSelectClauseStateObject
- Returns:
- The state object representing the FROM clause
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getParent
Description copied from interface:StateObject
Returns the parent of thisStateObject
.- Specified by:
getParent
in interfaceStateObject
- Overrides:
getParent
in classAbstractSelectClauseStateObject
- Returns:
- Returns the parent of this
StateObject
, which isnull
only when this is the root of the hierarchy
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getSelectItem
Returns -
hasSelectItem
public boolean hasSelectItem()Description copied from class:AbstractSelectClauseStateObject
Determines whether thisSELECT
clause has a select item defined (only one can be set for a subquery'sSELECT
clause and many for a top-level query).- Specified by:
hasSelectItem
in classAbstractSelectClauseStateObject
- Returns:
true
if this state object has children;false
otherwise
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isEquivalent
Description copied from interface:StateObject
Determines whether the givenStateObject
is equivalent to this one, i.e. the information of bothStateObject
is the same.- Specified by:
isEquivalent
in interfaceStateObject
- Overrides:
isEquivalent
in classAbstractSelectClauseStateObject
- Parameters:
stateObject
- TheStateObject
to compare its content to this one- Returns:
true
if both object are equivalent;false
otherwise
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parse
Description copied from class:AbstractSelectClauseStateObject
Parses the given JPQL fragment and create the select item. For the top-level query, the fragment can contain several select items but for a subquery, it can represent only one.- Specified by:
parse
in classAbstractSelectClauseStateObject
- Parameters:
jpqlFragment
- The portion of the query representing one or several select items
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setExpression
Keeps a reference of theparsed object
object, which should only be done when this object is instantiated during the conversion of a parsed JPQL query intoStateObjects
.- Parameters:
expression
- Theparsed object
representing a subquerySELECT
clause
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setSelectItem
Sets the givenStateObject
as this clause's select item.- Parameters:
stateObject
- TheStateObject
representing the single select item
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toTextInternal
Description copied from class:AbstractStateObject
Prints out a string representation of thisStateObject
, which should not be used to define atrue
string representation of a JPQL query but should be used for debugging purposes.- Specified by:
toTextInternal
in classAbstractStateObject
- Parameters:
writer
- The writer used to print out the string representation- Throws:
IOException
- This should never happens, it is only required becauseAppendable
is used instead of any concrete class
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