How to check whether a specific column exists in a table, for example, whether the student name exists in the table?

[cghw62382]

How to check whether a specific column exists in a table, for example, whether the student name exists in the table?

[lelloba]

Hello @cghw62382 ,

if you know the exact column name, I would to the following:

1. Use a Column Name Extractor node to get the column names
2. Use a Transpose node to get the values in a single column
3. Use a row filter to select the row

Something like this, but if you need it for something more specific tell me
Have a nice day,
Raffaello Barri

[Daniel_Weikert]

@cghw62382
You could try Table Validator node
br

[cghw62382]

@Daniel_Weikert

thanks, Daniel, now I want to replace the NULL value to “0” in the culumn “<=2000kbps+Count(gNodeB Name)”, but it can not work, I have tried Rule Engine Node, but below expression cannot work.
$<=2000kbps+Count(gNodeB Name)$ =“” => “0”

[cghw62382]

thanks Sir Lelloba, Table Validator (Reference) Node is better for my issue.

[cghw62382]

I have solved this issue of NULL value to 0 , add Missing Value Node.

[takbb]

I want to replace the NULL value to “0” in the culumn “<=2000kbps+Count(gNodeB Name)”, but it can not work, I have tried Rule Engine Node, but below expression cannot work.

Hi @cghw62382 , I’m glad to hear you found a solution with the Missing Value node. For future reference, the Rule Engine can achieve it, but a missing value is not the same as an empty string. Instead you need to use the MISSING keyword as below. For completeness I’ve also given a rule for when the column value is not missing (assuming this might occur): MISSING $<=2000kbps+Count(gNodeB Name)$ => “0” TRUE => $<=2000kbps+Count(gNodeB Name)$