How to find the previous value in a similar groups?

[Oracle]

Hi All,

Say i have the below scenario, wherever “kr” is there i need those previous values as “sh” and for “sh” of i have the previous value as “sh” then i need as “sh” only. So only for “kr” i need its overall previous value. For example:

column A        output
--------        ------
sh              null
kr              sh
kr              sh
kr              sh
sh              kr
sh              sh
kr              sh
kr              sh

Please help me in this. Thank you in advance!!

[ROSt53]

Your problem is not yet clear to me. I understand you have a column for which you want to make a test in a second column. Could you please make 5 examples for your the column, which content you want to test and make examples for the results you expect in the second column?

[Lupp]

Did you (“Oracle”) study Pythia’s words?

[oweng]

@ROSt53 @Lupp, I have edited the question to display the originally included example. It appears to be some sort of dual-criteria match problem i.e., if prior value in output column is NULL or sh then value is sh UNLESS same row in colA = sh AND previous row in colA = kr? That is the best I can come up with.