Very new to Q and I am having some issues loading my data into a table following the examples on the documentation.
I am running the following code:
table1: get `:pathname.csv
While it doesn't throw an error, when I run the following command nothing comes up:
select * from table1
Or when selecting a specific column:
select col1 from table1
If anyone could guide me in the right direction, that would be great!
Edit: This seems to work and retain all my columns:
table1: (9#"S";enlist csv) 0: `:data.CSV
You're going to need to use 0: https://code.kx.com/q/ref/filenumbers/#load-csv
The exact usage will depend on your csv, as you need to define the datatypes to load each column as.
As an example, here I have a CSV with a long, char & float column:
(kdb) chronos@localhost ~/Downloads $ more example.csv
abc,def,ghi
1,a,3.4
2,b,7.5
3,c,88
(kdb) chronos@localhost ~/Downloads $ q
KDB+ 3.6 2018.10.23 Copyright (C) 1993-2018 Kx Systems
l64/ 4()core 3894MB chronos localhost 127.0.0.1 EXPIRE 2019.06.15 [email protected] KOD #5000078
q)("JCF";enlist",")0:`:example.csv
abc def ghi
-----------
1 a 3.4
2 b 7.5
3 c 88
q)meta ("JCF";enlist",")0:`:example.csv
c | t f a
---| -----
abc| j
def| c
ghi| f
q)
I use the chars "JCF" to define the datatypes long, character & float respectively.
I enlist the delimiter (",") to indicate that the first row of the CSV contains the headers for the columns. (Otherwise, these can be supplied in your code & the table constructed)
On a side note, note that in q-sql, the * is not necessary as in standard SQL; you can simply do select from table1 to query all columns