sf.database.dbinfo

Enum ForeignKeyAction

java.lang.Object

java.lang.Enum<ForeignKeyAction>

sf.database.dbinfo.ForeignKeyAction

All Implemented Interfaces:

Serializable, Comparable<ForeignKeyAction>

public enum ForeignKeyAction
extends Enum<ForeignKeyAction>

外键的动作类型

Author:

Enum Constant Summary

Enum Constants

Enum Constant and Description
CASCADE 级联删除或更新。分别删除一个引用行或者更新一个引用列的值。
NO_ACTION 如果违反外键约束会产生一个错误。如果约束被延迟，那么到事务结束检查约束时如果仍然因为存在一个引用行而违反外键约束，则仍会产生错误。这是默认值。其他的动作action都不能被延迟。
RESTRICT 违反外键约束会产生一个错误。
SET_DEFAULT 设置引用列为其缺省值。如果缺省值不是null,那么仍然需要被引用表中有一条记录的被引用字段的值与之匹配，否则操作会失败。
SET_NULL 设置引用列的值为null

Method Summary

Modifier and Type	Method and Description
String	getName()
static ForeignKeyAction	parseName(String name)
static ForeignKeyAction	valueOf(String name) Returns the enum constant of this type with the specified name.
static ForeignKeyAction[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

NO_ACTION

public static final ForeignKeyAction NO_ACTION

如果违反外键约束会产生一个错误。如果约束被延迟，那么到事务结束检查约束时如果仍然因为存在一个引用行而违反外键约束，则仍会产生错误。这是默认值。其他的动作action都不能被延迟。

RESTRICT

public static final ForeignKeyAction RESTRICT

违反外键约束会产生一个错误。

CASCADE

public static final ForeignKeyAction CASCADE

级联删除或更新。分别删除一个引用行或者更新一个引用列的值。

SET_NULL

public static final ForeignKeyAction SET_NULL

设置引用列的值为null

SET_DEFAULT

public static final ForeignKeyAction SET_DEFAULT

设置引用列为其缺省值。如果缺省值不是null,那么仍然需要被引用表中有一条记录的被引用字段的值与之匹配，否则操作会失败。

Method Detail

values

public static ForeignKeyAction[] 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 (ForeignKeyAction c : ForeignKeyAction.values())
    System.out.println(c);

Returns:

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

valueOf

public static ForeignKeyAction 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

parseName

public static ForeignKeyAction parseName(String name)

getName

public String getName()