how to use flow variable

KNIME Analytics Platform
1

guys,

how to use flow variable? I can't comprehend the style of it,by the way, when can Ｉuse that red point (flow variable)?

thanks your answer!!

2

Hi,

you can use variables in many ways. If you want to understand how it works, they are in a way values without tables. You pass them from node to nodes with the red lins you talked about. To begin and make it more clear with I recommend you :

put the values of a table in variables :

table row to variable

table column to variable

put the variables values in tables :

variable to table column

variable to table row

For example, you want to put in a math formula the max of a numeric column and use this max value many times in other nodes. Without variables you have to calculate it with a group by and do cross joins to put it in your tables to make it available for each row of each table in which you want to use it as a column. Instead of it you calculate it with a group by and put it in a variable a pass this max value through nodes with the red links.

Take a look at the marvelous quick forms to inject variables in your workflow too.

Best regards,

Fabien

 

 

3

thank you! and my database can not work,what can I do?