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 vote264 views1 answer
Sql server python connection
SQL
0 vote267 views1 answer
Drop specific row postgresql
SQL
3 votes269 views1 answer
Force using index plsql
SQL
3 votes273 views4 answers
Show databases in sql server
SQL
0 vote309 views1 answer
Sql basic commands
SQL
1 vote268 views1 answer
Postgres first_value in gropby
SQL
2 votes291 views1 answer
Dbms transaction (psql)
SQL
11 votes256 views2 answers
Sql rank
SQL
0 vote265 views1 answer
Snap craft
SQL
2 votes254 views1 answer
Insert from table tsql
SQL