public enum JoinRelType extends java.lang.Enum<JoinRelType>
Enum Constant and Description |
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ANTI
Anti-join (also known as Anti-semi-join).
|
FULL
Full-outer join.
|
INNER
Inner join.
|
LEFT
Left-outer join.
|
RIGHT
Right-outer join.
|
SEMI
Semi-join.
|
Modifier and Type | Field and Description |
---|---|
java.lang.String |
lowerName
Lower-case name.
|
Modifier and Type | Method and Description |
---|---|
JoinRelType |
cancelNullsOnLeft()
Returns a join type similar to this but that does not generate nulls on
the left.
|
JoinRelType |
cancelNullsOnRight()
Returns a join type similar to this but that does not generate nulls on
the right.
|
boolean |
generatesNullsOn(int i)
Returns whether this join type generates nulls on side #
i . |
boolean |
generatesNullsOnLeft()
Returns whether a join of this type may generate NULL values on the
left-hand side.
|
boolean |
generatesNullsOnRight()
Returns whether a join of this type may generate NULL values on the
right-hand side.
|
boolean |
isOuterJoin()
Returns whether a join of this type is an outer join, returns true if the join type may
generate NULL values, either on the left-hand side or right-hand side.
|
boolean |
projectsRight() |
JoinRelType |
swap()
Swaps left to right, and vice versa.
|
static JoinRelType |
valueOf(java.lang.String name)
Returns the enum constant of this type with the specified name.
|
static JoinRelType[] |
values()
Returns an array containing the constants of this enum type, in
the order they are declared.
|
public static final JoinRelType INNER
public static final JoinRelType LEFT
public static final JoinRelType RIGHT
public static final JoinRelType FULL
public static final JoinRelType SEMI
For example, EMP semi-join DEPT
finds all EMP
records
that have a corresponding DEPT
record:
SELECT * FROM EMP WHERE EXISTS (SELECT 1 FROM DEPT WHERE DEPT.DEPTNO = EMP.DEPTNO)
public static final JoinRelType ANTI
For example, EMP anti-join DEPT
finds all EMP
records
that do not have a corresponding DEPT
record:
SELECT * FROM EMP WHERE NOT EXISTS (SELECT 1 FROM DEPT WHERE DEPT.DEPTNO = EMP.DEPTNO)
public static JoinRelType[] values()
for (JoinRelType c : JoinRelType.values()) System.out.println(c);
public static JoinRelType valueOf(java.lang.String name)
name
- the name of the enum constant to be returned.java.lang.IllegalArgumentException
- if this enum type has no constant with the specified namejava.lang.NullPointerException
- if the argument is nullpublic boolean generatesNullsOnRight()
public boolean generatesNullsOnLeft()
public boolean isOuterJoin()
public JoinRelType swap()
public boolean generatesNullsOn(int i)
i
.public JoinRelType cancelNullsOnLeft()
public JoinRelType cancelNullsOnRight()
public boolean projectsRight()
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