In SQL, how do I check what are the data in a categorical attribute?-CodePudding

For example, in a table, I have an attribute call "color", how to check what unique colors are included in the "color" attribute?

Name	Color
Alice	red
Ben	blue

Looking for a result that looks like: red, blue, green, black

Thanks in advance!

CodePudding user response：

Either you select the unique values of the column

select distinct color from yourtable

Or you group by the column

select color, count(*) as total
from yourtable
group by color
order by count(*) desc

CodePudding user response：

Use DISTINCT to return only different values:

SELECT DISTINCT Color FROM table_name;