程序包 org.hibernate.tool.hbm2ddl

枚举 UniqueConstraintSchemaUpdateStrategy

java.lang.Object

java.lang.Enum<UniqueConstraintSchemaUpdateStrategy>

org.hibernate.tool.hbm2ddl.UniqueConstraintSchemaUpdateStrategy

所有已实现的接口:

Serializable, Comparable<UniqueConstraintSchemaUpdateStrategy>

public enum UniqueConstraintSchemaUpdateStrategy
extends Enum<UniqueConstraintSchemaUpdateStrategy>

Unique columns and unique keys both use unique constraints in most dialects. SchemaUpdate needs to create these constraints, but DB's support for finding existing constraints is extremely inconsistent. Further, non-explicitly-named unique constraints use randomly generated characters.

作者:

Brett Meyer

枚举常量概要

枚举常量

枚举常量	说明
DROP_RECREATE_QUIETLY	Attempt to drop, then (re-)create each unique constraint.
RECREATE_QUIETLY	Attempt to (re-)create unique constraints, ignoring exceptions thrown (e.g., if the constraint already existed)
SKIP	Do not attempt to create unique constraints on a schema update

方法概要

修饰符和类型	方法	说明
static UniqueConstraintSchemaUpdateStrategy	byName(String name)
static UniqueConstraintSchemaUpdateStrategy	interpret(Object setting)
static UniqueConstraintSchemaUpdateStrategy	valueOf(String name)	返回带有指定名称的该类型的枚举常量。
static UniqueConstraintSchemaUpdateStrategy[]	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

DROP_RECREATE_QUIETLY

public static final UniqueConstraintSchemaUpdateStrategy DROP_RECREATE_QUIETLY

Attempt to drop, then (re-)create each unique constraint. Ignore any exceptions thrown. Note that this will require unique keys/constraints to be explicitly named. If Hibernate generates the names (randomly), the drop will not work. DEFAULT

RECREATE_QUIETLY

public static final UniqueConstraintSchemaUpdateStrategy RECREATE_QUIETLY

Attempt to (re-)create unique constraints, ignoring exceptions thrown (e.g., if the constraint already existed)

SKIP

public static final UniqueConstraintSchemaUpdateStrategy SKIP

Do not attempt to create unique constraints on a schema update

方法详细资料

values

public static UniqueConstraintSchemaUpdateStrategy[] 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 (UniqueConstraintSchemaUpdateStrategy c : UniqueConstraintSchemaUpdateStrategy.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 UniqueConstraintSchemaUpdateStrategy 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

byName

public static UniqueConstraintSchemaUpdateStrategy byName(String name)

interpret

public static UniqueConstraintSchemaUpdateStrategy interpret(Object setting)