Package org.apache.calcite.linq4j
Enum JoinType
- All Implemented Interfaces:
Serializable
,Comparable<JoinType>
,Constable
Enumeration of join types.
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Nested Class Summary
Nested classes/interfaces inherited from class java.lang.Enum
Enum.EnumDesc<E extends Enum<E>>
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Enum Constant Summary
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Method Summary
Modifier and TypeMethodDescriptionboolean
Returns whether a join of this type may generate NULL values on the left-hand side.boolean
Returns whether a join of this type may generate NULL values on the right-hand side.static JoinType
Returns the enum constant of this type with the specified name.static JoinType[]
values()
Returns an array containing the constants of this enum type, in the order they are declared.
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Enum Constant Details
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INNER
Inner join. -
LEFT
Left-outer join. -
RIGHT
Right-outer join. -
FULL
Full-outer join. -
SEMI
Semi-join.For example,
EMP semi-join DEPT
finds allEMP
records that have a correspondingDEPT
record:SELECT * FROM EMP WHERE EXISTS (SELECT 1 FROM DEPT WHERE DEPT.DEPTNO = EMP.DEPTNO)
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ANTI
Anti-join (also known as Anti-semi-join).For example,
EMP anti-join DEPT
finds allEMP
records that do not have a correspondingDEPT
record:SELECT * FROM EMP WHERE NOT EXISTS (SELECT 1 FROM DEPT WHERE DEPT.DEPTNO = EMP.DEPTNO)
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Method Details
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values
Returns an array containing the constants of this enum type, in the order they are declared.- Returns:
- an array containing the constants of this enum type, in the order they are declared
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valueOf
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)- Parameters:
name
- the name of the enum constant to be returned.- Returns:
- the enum constant with the specified name
- Throws:
IllegalArgumentException
- if this enum type has no constant with the specified nameNullPointerException
- if the argument is null
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generatesNullsOnRight
public boolean generatesNullsOnRight()Returns whether a join of this type may generate NULL values on the right-hand side. -
generatesNullsOnLeft
public boolean generatesNullsOnLeft()Returns whether a join of this type may generate NULL values on the left-hand side.
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