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 vote207 views1 answer
Create or replace view postgress
SQL
0 vote220 views1 answer
How to combine first and last nae into one columb sql
SQL
0 vote338 views1 answer
Provera dupliranih konatakata
SQL
0 vote203 views1 answer
Min salary in sql
SQL
0 vote194 views1 answer
Sqlite update only if greater
SQL
8 votes185 views1 answer
Sql remove characters from string right
SQL
0 vote206 views1 answer
Oracle SQL join three tables and group by column
SQL
0 vote221 views1 answer
Mysql:5.6 syntax create table
SQL
0 vote261 views1 answer
Sql ssrs
SQL
0 vote225 views1 answer
Minus equivalent in my sql
SQL