package com.primeton.dsp.datarelease.api.model;

import net.sf.jsqlparser.expression.Alias;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.ExpressionVisitor;
import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
import net.sf.jsqlparser.schema.Column;

/**
 * <pre>
 *
 * Created by zhenqin.
 * User: zhenqin
 * Date: 2020/4/28
 * Time: 17:48
 * Vendor: yiidata.com
 * To change this template use File | Settings | File Templates.
 *
 * </pre>
 *
 * @author zhenqin
 */
public class SelectField extends ASTNodeAccessImpl implements Expression {


    /**
     * 查询的字段，Column 是 final 无法继承造成的
     */
    private Column column;


    /**
     * 查询的字段别名
     */
    private Alias alias;


    public SelectField(Expression expression) {
        this((Column)expression);
    }



    public SelectField(Column expression) {
        this.column = expression;
    }


    public SelectField(Column expression, Alias alias) {
        this.column = expression;
        this.alias = alias;
    }

    public Column getExpression() {
        return column;
    }


    public Alias getAlias() {
        return alias;
    }

    public void setAlias(Alias alias) {
        this.alias = alias;
    }

    @Override
    public void accept(ExpressionVisitor expressionVisitor) {
        expressionVisitor.visit(column);
    }

    @Override
    public String toString() {
        return column + ((alias != null) ? alias.toString() : "");
    }
}