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 vote359 views2 answers
Sql now - 1 day
SQL
0 vote378 views1 answer
Oracle swap partition
SQL
5 votes373 views3 answers
Mysql update field from one table to another
SQL
0 vote380 views1 answer
Least spark sql
SQL
4 votes353 views5 answers
Primary key
SQL
3 votes368 views4 answers
Order by desc postgres
SQL
0 vote351 views1 answer
ORA-00942
SQL
0 vote386 views2 answers
Temp tables in sql server
SQL
0 vote462 views1 answer
Sp help text in postgresql
SQL
2 votes342 views2 answers
Checking data type in sql server
SQL