Adding column with primary key in existing table

Question

I am trying to add primary key to newly added column in existing table name Product_Details.

New Column added: Product_Detail_ID (int

Answer 1

If you want SQL Server to automatically provide values for the new column, make it an identity.

ALTER TABLE Product_Details DROP COLUMN Product_Detail_ID
GO
ALTER TABLE Product_Details ADD Product_Detail_ID int identity(1,1) not null
GO
ALTER TABLE Product_Details
add CONSTRAINT pk_Product_Detils_Product_Detail_ID primary key(Product_Detail_ID)
GO

Answer 2

ALTER TABLE Jaya 
  ADD CONSTRAINT no primary key(No);

here Jaya is table name,

no is column name,

ADD CONSTRAINT is we giving the primary key keyword

Answer 3

k. friend command: sql> alter table tablename add primary key(col_name);

ex: alter table pk_Product_Detils add primary key(Product_Detail_ID);

Answer 4

You are getting the error because you have existing data that does not fullfill the constraint.

There are 2 ways to fix it:

• clean up the existing data before adding the constraint
• add the constraint with the "WITH NOCHECK" option, this will stop sql server checking existing data, only new data will be checked

Answer 5

In mysql, I was able to achieve with following query

ALTER TABLE table_name ADD new_column int NOT NULL AUTO_INCREMENT primary key