How do I cast a string to a date in kdb?
e.g. Given the date string column in the table below, how do I convert it to a date column?
`
q)table:([] a:1 2 3; b:(“2016-11-01″;”2016-11-02″;”2016-11-03”))
q)table
a b
————–
1 “2016-11-01”
2 “2016-11-02”
3 “2016-11-03”
`
Perform an update casting the column using an upper case letter D-for type like so:
`q)update “D”$b from table
a b
————
1 2016.11.01
2 2016.11.02
3 2016.11.03
`
If the date was in a different format mm-dd vs dd-mm or UK vs US date format you could first rearrange the strings then cast:
`
q)update {x[0 1 2 3 4 8 9 7 5 6]} each b from table
a b
————–
1 “2016-01-11”
2 “2016-02-11”
3 “2016-03-11”
q)update “D”${x[0 1 2 3 4 8 9 7 5 6]} each b from table
a b
————
1 2016.01.11
2 2016.02.11
3 2016.03.11
q)meta update “D”${x[0 1 2 3 4 8 9 7 5 6]} each b from table
c| t f a
-| —–
a| j
b| d
`
.
