See how many unique values of the joining key exist in your data.

Give this function as many data frames as you want and the key and it tells you how many unique values are in each data frame for the keys you specify.

count_keys(..., df_names = NULL, keys)

Arguments

...	enter as many data frames as you would like
df_names	the data frame names
keys	the primary key or other key you wish to analyze

Examples

count_keys(demographics, math, ell, keys = c("student_id", "year"))
#> # A tibble: 30,000 x 5
#>    student_id  year demographics  math   ell
#>    <chr>      <dbl>        <int> <int> <int>
#>  1 S1000227    2015            1     1     0
#>  2 S1000227    2016            1     0     0
#>  3 S1000227    2017            1     1     0
#>  4 S1002738    2015            1     1     0
#>  5 S1002738    2016            1     1     0
#>  6 S1002738    2017            1     1     0
#>  7 S1003071    2015            1     1     0
#>  8 S1003071    2016            1     0     0
#>  9 S1003071    2017            1     1     0
#> 10 S100408     2015            1     0     0
#> # ... with 29,990 more rows
count_keys(list(demographics, math, ell),
     df_names = c("demographics", "math", "ell"),
     keys = c("student_id", "year"))
#> # A tibble: 30,000 x 5
#>    student_id  year demographics  math   ell
#>    <chr>      <dbl>        <int> <int> <int>
#>  1 S1000227    2015            1     1     0
#>  2 S1000227    2016            1     0     0
#>  3 S1000227    2017            1     1     0
#>  4 S1002738    2015            1     1     0
#>  5 S1002738    2016            1     1     0
#>  6 S1002738    2017            1     1     0
#>  7 S1003071    2015            1     1     0
#>  8 S1003071    2016            1     0     0
#>  9 S1003071    2017            1     1     0
#> 10 S100408     2015            1     0     0
#> # ... with 29,990 more rows