org.apache.calcite.linq4j

枚举 JoinType

java.lang.Object

java.lang.Enum<JoinType>

org.apache.calcite.linq4j.JoinType

所有已实现的接口:

Serializable, Comparable<JoinType>

public enum JoinType
extends Enum<JoinType>

Enumeration of join types.

枚举常量概要

枚举常量

枚举常量和说明
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.

方法概要

限定符和类型	方法和说明
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.
static JoinType	valueOf(String name) 返回带有指定名称的该类型的枚举常量。
static JoinType[]	values() 按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。

从类继承的方法 java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

从类继承的方法 java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

枚举常量详细资料

INNER

public static final JoinType INNER

Inner join.

LEFT

public static final JoinType LEFT

Left-outer join.

RIGHT

public static final JoinType RIGHT

Right-outer join.

FULL

public static final JoinType FULL

Full-outer join.

SEMI

public static final JoinType SEMI

Semi-join.

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)

ANTI

public static final JoinType ANTI

Anti-join (also known as Anti-semi-join).

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)

方法详细资料

values

public static JoinType[] values()

按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。该方法可用于迭代 常量, 如下所示:

for (JoinType c : JoinType.values())
    System.out.println(c);

返回:

按照声明该枚举类型的常量的顺序返回的包含这些常量的数组

valueOf

public static JoinType valueOf(String name)

返回带有指定名称的该类型的枚举常量。 字符串必须与用于声明该类型的枚举常量的 标识符完全匹配。(不允许有多余 的空格字符。)

参数:

name - 要返回的枚举常量的名称。

返回:

返回带有指定名称的枚举常量

抛出:

IllegalArgumentException - 如果该枚举类型没有带有指定名称的常量

NullPointerException - 如果参数为空值

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.