Primary key in sql

Sql primary key

/* A primary key allows each record in a table to be uniquely identified. There can only be one
primary key per table, and you can assign this constraint to any single or combination of columns.
However, this means each value within this column(s) must be unique.
Typically in a table, the primary key is an ID column, and is usually paired with the AUTO_
INCREMENT keyword. This means the value increases automatically as new records are created. */
CREATE TABLE stats(id INT NOT NULL PRIMARY KEY, name TEXT)

Primary key sql

CREATE TABLE student

(

Roll integer (15) NOT NULL PRIMARY KEY,

Name varchar (255),

Class varchar (255),

Contact No varchar (255),

);

Source: wlearnsmart.com

Primary key in sql

Primary Key :
It is unique column in every table in a database
It can ONLY accept;
    - nonduplicate values
    - cannot be NULL

Primary key in sql

منحصر به فرد بودن هر رکورد

Similar codes

3 votes306 views2 answers
How to force truncate a table in mysql
SQL
1 vote277 views1 answer
Postgres concat_ws
SQL
13 votes270 views2 answers
Mysql order by multiple columns
SQL
0 vote267 views1 answer
Price-colour
SQL
1 vote267 views1 answer
Median mysql
SQL
0 vote281 views2 answers
Postgres show current role
SQL
0 vote287 views1 answer
How to check event scheduler status mysql
SQL
13 votes285 views3 answers
Sql select from multiple tables without join
SQL
4 votes287 views1 answer
Mysql copy table with new name
SQL
5 votes307 views1 answer
Mysql add user with all privileges
SQL