SQL to find the number of distinct values in a column

Question

I can select all the distinct values in a column in the following ways:

• SELECT DISTINCT column_name FROM table_name;
• SELECT column_

Answer 1

Count(distinct({fieldname})) is redundant

Simply Count({fieldname}) gives you all the distinct values in that table. It will not (as many presume) just give you the Count of the table [i.e. NOT the same as Count(*) from table]