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

-1 vote155 views1 answer
Ssql to lowercqse
SQL
0 vote155 views1 answer
Change schema of all tables postgres
SQL
0 vote164 views1 answer
Create table with float datatype in sql server
SQL
1 vote170 views1 answer
Oracle index partition
SQL
0 vote151 views1 answer
Backup and restore of sqlite database from c# -sqlserver
SQL
1 vote228 views1 answer
Get the User Name and Domain Name from an Email Address
SQL
2 votes141 views1 answer
Create table with primary key
SQL
0 vote188 views1 answer
Postgresql concat string with separator
SQL
2 votes202 views1 answer
Oracle Column Names of a table
SQL
0 vote159 views1 answer
Mod function example
SQL