/*
 * Copyright 2016-2018 shardingsphere.io.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * </p>
 */

package io.shardingsphere.core.parsing.parser.context.selectitem;

import com.google.common.base.Optional;

/**
 * Select item interface.
 *
 * @author zhangliang
 */
public interface SelectItem {
    
    /**
     * 获取表达式.
     * 
     * @return 表达式
     */
    String getExpression();
    
    /**
     * 获取别名.
     * 
     * @return 别名
     */
    Optional<String> getAlias();
}

@@ -834,13 +834,22 @@
   * 
-%E8%8E%B7%E5%8F%96%E8%A1%A8%E8%BE%BE%E5%BC%8F
+Get expression
 .%0A  
@@ -873,11 +873,18 @@
 urn 
-%E8%A1%A8%E8%BE%BE%E5%BC%8F
+expression
 %0A   
@@ -940,12 +940,17 @@
   * 
-%E8%8E%B7%E5%8F%96%E5%88%AB%E5%90%8D
+Get alias
 .%0A  
@@ -974,10 +974,13 @@
 urn 
-%E5%88%AB%E5%90%8D
+alias
 %0A   

update java doc