DolphinDB 中的内存表:
t=table(10:0,`time`sym`bid`ofr,[TIMESTAMP,SYMBOL,DOUBLE,DOUBLE])
想为 t 添加一个新的列数,我尝试了函数 addColumn,它不起作用。
addColumn(t,`count,[INT])
execution was completed with exception
Usage: addColumn(table, newColNames, newColTypes). table must be a streaming table or a dfs-based table.