Rule Engine Function LIKE is case sensitive? & MATCHES is case insensitive?

[VishalM0228]

Hi everyone,

I am a new to KNIME platform.
I would like confirm on the rule engine functions ‘LIKE’ and ‘MATCHES’. about their case sensitivity.
In my case I have a column with aloha numeric codes such as PCPO02BAY533 , and I am checking occurrences of PO in the string, if matched it will be assigned to a category name. for now I am using LIKE function with this “PO” search.

Please help to provide your suggestions and right way in above scenario. Thanks

[victor_palacios]

Hello,

LIKE and MATCHES in KNIME’s Rule Engine is case sensitive and require a * otherwise it will try to match exactly what is in the cell to your search.

If you’re worried about casing, simply uppercase your entire column using the String Manipulation node: upperCase($column1$)

and then run your rule engine with LIKE:

$column1$ LIKE “PO” => 1 will not find a match with PCPOX or POX

VS

$column1$ LIKE “*PO*” => 1 will find a match with PCPOX and POX

You can see an example of how to use LIKE in the “description” pane once you click on the Rule Engine node as well:

An alternative is Regex (Regular Expressions)

You can also use regexMatcher or regexReplace within the String Manipulation node:
regexMatcher($column1$, “.*(PO).*”)

The Operator MATCHES is based on regular expressions:
$column1$ MATCHES “.*PO.*” => 1

[VishalM0228]

Thank you Victor,
I am going with uppercasing the column and then running a match.
I have applied rule engine (dictionary).