Class HierarchicalQueryClause
- java.lang.Object
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- org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
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- org.eclipse.persistence.jpa.jpql.parser.HierarchicalQueryClause
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- All Implemented Interfaces:
Expression
public final class HierarchicalQueryClause extends AbstractExpression
If a table contains hierarchical data, then rows can be selected in a hierarchical order using the hierarchical query clause.START WITH
specifies the root row(s) of the hierarchy.CONNECT BY
specifies the relationship between parent rows and child rows of the hierarchy.BNF:hierarchical_query_clause ::= [start_with_clause] connectby_clause [order_siblings_by_clause]
- Since:
- 2.5
- Version:
- 2.5
- Author:
- Pascal Filion
- See Also:
StartWithClause
,ConnectByClause
,OrderSiblingsByClause
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Field Summary
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Fields inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE
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Fields inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression
ABS, ALL, AND, ANY, AS, AS_OF, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, CONNECT_BY, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXCEPT, EXISTS, EXTRACT, FALSE, FETCH, FIRST, FROM, FUNC, FUNCTION, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, INTERSECT, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, LAST, LEADING, LEFT, LEFT_JOIN, LEFT_JOIN_FETCH, LEFT_OUTER_JOIN, LEFT_OUTER_JOIN_FETCH, LENGTH, LIKE, LOCATE, LOWER, LOWER_THAN, LOWER_THAN_OR_EQUAL, MAX, MEMBER, MEMBER_OF, MIN, MINUS, MOD, MULTIPLICATION, NAMED_PARAMETER, NEW, NOT, NOT_BETWEEN, NOT_EQUAL, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, NULLS, NULLS_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, ORDER_SIBLINGS_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SCN, SELECT, SET, SIZE, SOME, SQL, SQRT, START_WITH, SUBSTRING, SUM, TABLE, THEN, TIMESTAMP, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE
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Constructor Summary
Constructors Constructor Description HierarchicalQueryClause(AbstractExpression parent)
Creates a newHierarchicalQueryClause
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
accept(ExpressionVisitor visitor)
Visits thisExpression
by the givenvisitor
.void
acceptChildren(ExpressionVisitor visitor)
Visits the children of thisExpression
.JPQLQueryBNF
findQueryBNF(Expression expression)
Retrieves theJPQLQueryBNF
that represents the fragment of thisExpression
that was used when parsing the givenExpression
.Expression
getConnectByClause()
Returns theExpression
representing the CONNECT BY clause.Expression
getOrderSiblingsByClause()
Returns theExpression
representing the ORDER SIBLINGS BY clause.JPQLQueryBNF
getQueryBNF()
Returns the BNF of thisExpression
.Expression
getStartWithClause()
Returns theExpression
representing the START WITH clause.boolean
hasConnectByClause()
Determines whether the CONNECT BY clause is defined.boolean
hasOrderSiblingsByClause()
Determines whether the ORDER SIBLINGS BY clause is defined.boolean
hasSpaceAfterConnectByClause()
Determines whether a whitespace was found after theCONNECT BY
clause.boolean
hasSpaceAfterStartWithClause()
Determines whether a whitespace was found after theSTART WITH
clause.boolean
hasStartWithClause()
Determines whether the START WITH clause is defined.-
Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
children, getGrammar, getIdentifierVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, isAncestor, orderedChildren, populatePosition, toActualText, toParsedText, toString
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Constructor Detail
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HierarchicalQueryClause
public HierarchicalQueryClause(AbstractExpression parent)
Creates a newHierarchicalQueryClause
.- Parameters:
parent
- The parent of this expression
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Method Detail
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accept
public void accept(ExpressionVisitor visitor)
Visits thisExpression
by the givenvisitor
.- Parameters:
visitor
- TheExpressionVisitor
to visit this object
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acceptChildren
public void acceptChildren(ExpressionVisitor visitor)
Visits the children of thisExpression
. This method can be used to optimize traversing the children since a new list is not created every timeExpression.children()
is called.This does not traverse the
Expression
sub-hierarchy, use a subclass ofAbstractTraverseChildrenVisitor
in order to traverse the entire sub-hierarchy.- Parameters:
visitor
- Thevisitor
to visit the children of this object.
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findQueryBNF
public JPQLQueryBNF findQueryBNF(Expression expression)
Retrieves theJPQLQueryBNF
that represents the fragment of thisExpression
that was used when parsing the givenExpression
.- Specified by:
findQueryBNF
in interfaceExpression
- Overrides:
findQueryBNF
in classAbstractExpression
- Parameters:
expression
- TheExpression
that is a descendant of this one- Returns:
- The
JPQLQueryBNF
that was used to parse the given expression
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getConnectByClause
public Expression getConnectByClause()
Returns theExpression
representing the CONNECT BY clause.- Returns:
- The expression representing the CONNECT BY clause
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getOrderSiblingsByClause
public Expression getOrderSiblingsByClause()
Returns theExpression
representing the ORDER SIBLINGS BY clause.- Returns:
- The expression representing the ORDER SIBLINGS BY clause
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getQueryBNF
public JPQLQueryBNF getQueryBNF()
Returns the BNF of thisExpression
.- Returns:
- The
JPQLQueryBNF
, which represents the grammar of thisExpression
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getStartWithClause
public Expression getStartWithClause()
Returns theExpression
representing the START WITH clause.- Returns:
- The expression representing the START WITH clause
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hasConnectByClause
public boolean hasConnectByClause()
Determines whether the CONNECT BY clause is defined.- Returns:
true
if the query that got parsed had the CONNECT BY clause
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hasOrderSiblingsByClause
public boolean hasOrderSiblingsByClause()
Determines whether the ORDER SIBLINGS BY clause is defined.- Returns:
true
if the query that got parsed had the ORDER SIBLINGS BY clause
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hasSpaceAfterConnectByClause
public boolean hasSpaceAfterConnectByClause()
Determines whether a whitespace was found after theCONNECT BY
clause. In some cases, the space is owned by a child of the hierarchical query clause.- Returns:
true
if there was a whitespace after theCONNECT BY
clause and owned by this expression;false
otherwise
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hasSpaceAfterStartWithClause
public boolean hasSpaceAfterStartWithClause()
Determines whether a whitespace was found after theSTART WITH
clause. In some cases, the space is owned by a child of the hierarchical query clause.- Returns:
true
if there was a whitespace after theSTART WITH
clause and owned by this expression;false
otherwise
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hasStartWithClause
public boolean hasStartWithClause()
Determines whether the START WITH clause is defined.- Returns:
true
if the query that got parsed had the START WITH clause
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