dataFrame selectExpr 使用示例

使用udf函数 别名添加一列值

直接用sql

 var df_score = (" SELECT * , get_score(speed_up,speed_down,highspeed_count,start_time,end_time,avg_speed) as SCORE FROM locus_travel");

用selectExpre

 var df_score = df_poi.selectExpr("*", "get_score(speed_up,speed_down,highspeed_count,start_time,end_time,avg_speed) as SCORE ");

添加一列

df_score.withColumn(colName, col)