org.apache.crunch.lib.join

Enum JoinType

java.lang.Object

java.lang.Enum<JoinType>

org.apache.crunch.lib.join.JoinType

All Implemented Interfaces:

Serializable, Comparable<JoinType>

public enum JoinType
extends Enum<JoinType>

Specifies the specific behavior of how a join should be performed in terms of requiring matching keys on both sides of the join.

Enum Constant Summary

Enum Constants

Enum Constant and Description
FULL_OUTER_JOIN Join two tables on a common key, also including entries from both tables that have no matching key in the other table.
INNER_JOIN Join two tables on a common key.
LEFT_OUTER_JOIN Join two tables on a common key, including entries from the left-side table that have no matching key in the right-side table.
RIGHT_OUTER_JOIN Join two tables on a common key, including entries from the right-side table that have no matching key in the left-side table.

Method Summary

Modifier and Type	Method and Description
static JoinType	valueOf(String name) 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.

Methods inherited from class java.lang.Enum

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

INNER_JOIN

public static final JoinType INNER_JOIN

Join two tables on a common key. Every value in the left-side table under a given key will be present with every value from the right-side table with the same key.

See Also:

Inner Join

LEFT_OUTER_JOIN

public static final JoinType LEFT_OUTER_JOIN

Join two tables on a common key, including entries from the left-side table that have no matching key in the right-side table.

This is an optional method for implementations.

See Also:

Left Join

RIGHT_OUTER_JOIN

public static final JoinType RIGHT_OUTER_JOIN

Join two tables on a common key, including entries from the right-side table that have no matching key in the left-side table.

This is an optional method for implementations.

See Also:

Right Join

FULL_OUTER_JOIN

public static final JoinType FULL_OUTER_JOIN

Join two tables on a common key, also including entries from both tables that have no matching key in the other table.

This is an optional method for implementations.

See Also:

Full Join

Method Detail

values

public static JoinType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

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

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static JoinType valueOf(String name)

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 name

NullPointerException - if the argument is null