定义一个参数转换的函数,参数为mutable t,返回t的类型转换的结果,在导入数据时,把这个函数赋值给transform参数。
举例如下:
def transform_type(mutable t)
{
return t.replaceColumn!(`DateTime,datetimeParse(string(t.DateTime),"yyyyMMdd")).replaceColumn!(`SecurityID,t.SecurityID + `.SH)
}
loadTextEx(dbHandle=db,tableName=`sh_k_day,partitionColumns=`DateTime`SecurityID,filename="/home/ychan/data/sh/20210901/Day.csv",transform = transform_type,schema = schema_snapshot,skipRows=1)