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 vote187 views2 answers
Call to undefined function mysqli_fetch_all()
SQL
0 vote192 views1 answer
Pagination with row_number
SQL
0 vote219 views1 answer
Sql convert unix time to date
SQL
10 votes183 views4 answers
SELECT FROM WHERE
SQL
0 vote270 views1 answer
1422: Explicit or implicit commit is not allowed in stored function or trigger
SQL
0 vote205 views1 answer
Sql query inline if
SQL
2 votes221 views1 answer
Show max_allowed_packet mysql
SQL
0 vote185 views1 answer
Insert into using contant values and source table columns with sql
SQL
0 vote280 views1 answer
Import sql dump into postgresql database
SQL
3 votes189 views1 answer
Select sequence oracle
SQL