程序包 org.hibernate.dialect

枚举 ResultColumnReferenceStrategy

java.lang.Object

java.lang.Enum<ResultColumnReferenceStrategy>

org.hibernate.dialect.ResultColumnReferenceStrategy

所有已实现的接口:

Serializable, Comparable<ResultColumnReferenceStrategy>

public enum ResultColumnReferenceStrategy
extends Enum<ResultColumnReferenceStrategy>

Defines how we need to reference columns in the group-by, having, and order-by clauses.

作者:

Steve Ebersole

枚举常量概要

枚举常量

枚举常量	说明
ALIAS	For databases which do not support SOURCE, ANSI SQL defines two allowable approaches.
ORDINAL	For databases which do not support SOURCE, ANSI SQL defines two allowable approaches.
SOURCE	This strategy says to reference the result columns by the qualified column name found in the result source.

方法概要

修饰符和类型	方法	说明
static ResultColumnReferenceStrategy	resolveByName(String name)	Resolves the strategy by name, in a case insensitive manner.
static ResultColumnReferenceStrategy	valueOf(String name)	返回带有指定名称的该类型的枚举常量。
static ResultColumnReferenceStrategy[]	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

SOURCE

public static final ResultColumnReferenceStrategy SOURCE

This strategy says to reference the result columns by the qualified column name found in the result source. This strategy is not strictly allowed by ANSI SQL but is Hibernate's legacy behavior and is also the fastest of the strategies; thus it should be used if supported by the underlying database.

ALIAS

public static final ResultColumnReferenceStrategy ALIAS

For databases which do not support SOURCE, ANSI SQL defines two allowable approaches. One is to reference the result column by the alias it is given in the result source (if it is given an alias). This strategy says to use this approach.

The other ANSI SQL compliant approach is ORDINAL.

ORDINAL

public static final ResultColumnReferenceStrategy ORDINAL

For databases which do not support SOURCE, ANSI SQL defines two allowable approaches. One is to reference the result column by the ordinal position at which it appears in the result source. This strategy says to use this approach.

The other ANSI SQL compliant approach is ALIAS.

方法详细资料

values

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

resolveByName

public static ResultColumnReferenceStrategy resolveByName(String name)

Resolves the strategy by name, in a case insensitive manner. If the name cannot be resolved, SOURCE is returned as the default.

参数:

name - The strategy name to resolve

返回:

The resolved strategy