R Quick Solution:
Problem: What to know which columns have NULL value in dataset?
Solution:
Data set: r_data
> for(varr in names(r_data))
{
print(varr)
print(sum(is.na(r_ data[varr])))
}
Output:
[1] "SD_ID"
[1] 0
[1] "ZIP"
[1] 0
[1] "COUNTY"
[1] 0
[1] "LATITUDE"
[1] 20
[1] 0
[1] "ZIP"
[1] 0
[1] "COUNTY"
[1] 0
[1] "LATITUDE"
[1] 20
It
means variable Latitude has 20 missing values. So you to investigate it
and substitute the missing value based on your business requirement.