/*
* JEF - Copyright 2009-2010 Jiyi (mr.jiyi@gmail.com)
*
* 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.
*/
package jef.database.jsqlparser.visitor;
import jef.database.jsqlparser.expression.Table;
import jef.database.jsqlparser.statement.SqlAppendable;
import jef.database.jsqlparser.statement.select.SelectExpressionItem;
/**
* Anything between "SELECT" and "FROM"<BR>
* (that is, any column or expression etc to be retrieved with the query)
*/
public interface SelectItem extends SqlAppendable{
public void accept(SelectItemVisitor selectItemVisitor);
/**
* 返回查询表达式。如果是AllColumn * /t.*等格式则抛出异常,因此在调用此方法之前要先按isAllColumns进行判断
* @return
*/
public SelectExpressionItem getAsSelectExpression();
/**
* 如果是AllColumn类型 * /t.*返回其所属表。如果是Expression类型会抛出异常
* @return
*/
public Table getTableOfAllColumns();
/**
* 拼入对象
* @param sb
* @param noGroupFunc
*/
public String getStringWithoutGroupFuncAndAlias();
/**
* 是否为 t.*, *等格式的
* @return
*/
public boolean isAllColumns();
}