CODEWITHSUNDEEP
replacekdb+
Terry
Terry

Reputation: 519

Replace certain records in a column with given condition in kdb

I have a table below:

tab:([]a:(`$"1-01";`2;`$"3-01";`4;`$"5-01";`6);source:`a`a`b`b`a`b)

a    source
-----------
1-01 a     
2    a     
3-01 b     
4    b     
5-01 a     
6    b

I would like to change the 1-01 and 5-01 back to 1 but not for 3-01 depending on the source. I wrote the code below:

`$({ssr[string x;"-01";""]}each tab[`a])

by doing this I can put this back to a column, but this is not what I want. I also did the following:

`$({ssr[string x;"-01";""]}each tab[`a] where source=`a)

but after doing this I do not know how to put it back to the table. Then I thought of using execution control: but not sure how i should code it. I have it half way done and it does not really work:

?[tab[`source] = `a;`$({ssr[string tab[`a];"-01";""]});tab[`a]]

Upvotes: 0

Views: 1894

Answers (1)

terrylynch
terrylynch

Reputation: 13572

An "update" seems to be what you need:

q)update `$ssr[;"-01";""] each string a from tab where source=`a
a    source
-----------
1    a
2    a
3-01 b
4    b
5    a
6    b

Upvotes: 2

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