How to find unique element in sql

DISTINCT
- select distinct * from employees; ==> 
           retrieves any row if it has at 
           least a single unique column.
- select distinct first_name from employees; ==> 
              retrieves unique names
              from table. (removes duplicates)
- select distinct count(*) from employees;
          retrieve number of unique rows
          if any row has at least a single unique data.

Similar codes

0 vote130 views1 answer
Sql server select ignore dupplicates
SQL
2 votes174 views1 answer
Get the mysql table columns data type mysql
SQL
0 vote148 views1 answer
How to remove quotes from a string in ssis load file
SQL
0 vote169 views1 answer
Update mysql from paypal shopping cart and ipn
SQL
0 vote116 views2 answers
Get top 1 row of each group
SQL
1 vote159 views1 answer
Ora-01109 database not open in oracle 19c
SQL
1 vote137 views2 answers
Datetrunc hour snowflake
SQL
14 votes134 views2 answers
Oracle export trigger ddl
SQL
0 vote117 views1 answer
Minus equivalent in my sql
SQL
3 votes212 views2 answers
Savepoint in sql
SQL