change primary key sql
ALTER TABLE <Table_Name>
DROP CONSTRAINT <constraint_name>
ALTER TABLE <Table_Name>
ADD CONSTRAINT <constraint_name> PRIMARY KEY (<Column1>,<Column2>)change primary key sql
ALTER TABLE <Table_Name>
DROP CONSTRAINT <constraint_name>
ALTER TABLE <Table_Name>
ADD CONSTRAINT <constraint_name> PRIMARY KEY (<Column1>,<Column2>)sql primary key
-- NOTE: this is for SQL-Oracle specifically
-- example:
SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner
FROM all_constraints cons, all_cons_columns cols
WHERE cols.table_name = 'CUSTOMERS'
AND cons.constraint_type = 'P'
AND cons.constraint_name = cols.constraint_name
AND cons.owner = cols.owner;
-- syntax:
SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner
FROM all_constraints cons, all_cons_columns cols
WHERE cols.table_name = '<table-name>' -- Replace <table-name> with your table-name
AND cons.constraint_type = 'P'
AND cons.constraint_name = cols.constraint_name
AND cons.owner = cols.owner;primary key sql
CREATE TABLE student
(
Roll integer (15) NOT NULL PRIMARY KEY,
Name varchar (255),
Class varchar (255),
Contact No varchar (255),
);primary key in sql
Primary Key :
It is unique column in every table in a database
It can ONLY accept;
- nonduplicate values
- cannot be NULLCopyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
