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

0 vote187 views1 answer
Pl sql search saurce code
SQL
1 vote190 views1 answer
Psql filed name alter
SQL
1 vote213 views1 answer
Illuminate\Database\QueryException SQLSTATE[HY000] [2002] Connection refused (SQL: select * from information_schema.tables where table_schema = laravel and table_name = migrations and table_type = 'BASE TABLE')
SQL
0 vote204 views2 answers
How do I install microsoft SQL on my Mac?
SQL
0 vote194 views1 answer
Psql datestyle
SQL
0 vote177 views1 answer
Mysql events not work
SQL
3 votes208 views1 answer
Oracle show trigger code
SQL
0 vote196 views1 answer
Cast as decimal postgresql
SQL
35 votes196 views6 answers
Postgres
SQL
0 vote196 views1 answer
UNION ALL LEFT JOIN
SQL