/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.dialect;

Defines how we need to reference columns in the group-by, having, and order-by
clauses.
Author:
Steve Ebersole/**
 * Defines how we need to reference columns in the group-by, having, and order-by
 * clauses.
 *
 * @author Steve Ebersole
 */
public enum ResultColumnReferenceStrategy {
	
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.
/**
	 * 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.
	 */
	SOURCE,
	
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 QNSI SQL compliant approach is ORDINAL. /**
	 * For databases which do not support {@link #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.
	 * <p/>
	 * The other QNSI SQL compliant approach is {@link #ORDINAL}.
	 */
	ALIAS,
	
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 QNSI SQL compliant approach is ALIAS. /**
	 * For databases which do not support {@link #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.
	 * <p/>
	 * The other QNSI SQL compliant approach is {@link #ALIAS}.
	 */
	ORDINAL;

	
Resolves the strategy by name, in a case insensitive manner. If the name cannot be resolved, SOURCE is returned as the default. 
Params:
name – The strategy name to resolve
Returns:
The resolved strategy/**
	 * Resolves the strategy by name, in a case insensitive manner.  If the name cannot be resolved, {@link #SOURCE}
	 * is returned as the default.
	 *
	 * @param name The strategy name to resolve
	 *
	 * @return The resolved strategy
	 */
	public static ResultColumnReferenceStrategy resolveByName(String name) {
		if ( ALIAS.name().equalsIgnoreCase( name ) ) {
			return ALIAS;
		}
		else if ( ORDINAL.name().equalsIgnoreCase( name ) ) {
			return ORDINAL;
		}
		else {
			return SOURCE;
		}
	}
}