Sql unique

Sql unique select

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

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

Sql unique

This constraint ensures all values in a column are unique.
Example 1 (MySQL): Adds a unique constraint to the id column when
creating a new users table.
CREATE TABLE users (
id int NOT NULL,
name varchar(255) NOT NULL,
UNIQUE (id)
);
Example 2 (MySQL): Alters an existing column to add a UNIQUE
constraint.
ALTER TABLE users
ADD UNIQUE (id);

Similar codes

0 vote143 views1 answer
Create domain sql
SQL
0 vote159 views1 answer
Calculer pourcentage mysql
SQL
0 vote137 views1 answer
How many rows affected in sqllite
SQL
11 votes317 views4 answers
Round in sql
SQL
0 vote124 views1 answer
Sub blocks in sql
SQL
0 vote136 views1 answer
Difference between min and max date sql
SQL
0 vote145 views1 answer
Sqlites studio red exclamation mark when poening databse
SQL
0 vote303 views1 answer
Get first match in each group mysql query
SQL
12 votes148 views6 answers
Select distinct
SQL
6 votes131 views5 answers
Mysqli_real_connect(): (HY000/1698): Access denied for user 'root'@'localhost'
SQL