Unique in sql server

Sql unique rows

SELECT
DISTINCT country
FROM City;

Source: learnsql.com

Unique in sql server

CREATE TABLE Persons (
    ID int NOT NULL UNIQUE,
    LastName varchar(255) NOT NULL,
    FirstName varchar(255),
    Age int
);

How to select 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.

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.

Sql unique select

SELECT DISTINCT col1, col2, ....
FROM table_name;

SELECT col1, MIN(col2)
FROM table_name
GROUP BY col1;

Similar codes

1 vote113 views1 answer
Duplicating a MySQL table with all the data Command
SQL
0 vote121 views1 answer
Oracle table privileges
SQL
0 vote118 views1 answer
Fix sqlite3 ruby on rails
SQL
1 vote122 views1 answer
Select inside insert query
SQL
2 votes114 views2 answers
Mysql add hours to time field
SQL
0 vote136 views1 answer
Min varias colunas spark sql
SQL
3 votes119 views1 answer
Postgres count distinct
SQL
-1 vote118 views1 answer
Concat two columns in sql server
SQL
0 vote114 views1 answer
Example of sql querry result sepapreted by comma
SQL
1 vote110 views1 answer
Column with prefix in sql
SQL