How to assign primary key or forign key to existing tables

Hi,

I am new to SQL server. I have one doubt.

I am using SQL server 2005 Express Edition

I have two tables which I created earlier. Now I need to coonect these tables using primary key and foreign key.
So how can I assign these PK and Fk to these tables?
Thanks in advance.
Siju George

Quote:

Originally Posted by sijugeo

Hi,

I am new to SQL server. I have one doubt.

I am using SQL server 2005 Express Edition

I have two tables which I created earlier. Now I need to coonect these tables using primary key and foreign key.
So how can I assign these PK and Fk to these tables?
Thanks in advance.
Siju George

Hi
You can do by searching in sql books online.
Ok......add primary key constraint on one column in one table using alter table add constraint.add refference constraint on one column in other table
example:
[code]

CREATE TABLE doc_exe ( column_a INT CONSTRAINT column_a_un UNIQUE) ;
GO
ALTER TABLE doc_exe ADD

-- Add a PRIMARY KEY identity column.
column_b INT IDENTITY
CONSTRAINT column_b_pk PRIMARY KEY,

-- Add a column that references another column in the same table.
column_c INT NULL
CONSTRAINT column_c_fk
REFERENCES doc_exe(column_a),

-- Add a column with a constraint to enforce that
-- nonnull data is in a valid telephone number format.
column_d VARCHAR(16) NULL
CONSTRAINT column_d_chk
CHECK
(column_d LIKE '[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]' OR
column_d LIKE
'([0-9][0-9][0-9]) [0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]'),

-- Add a nonnull column with a default.
column_e DECIMAL(3,3)
CONSTRAINT column_e_default
DEFAULT .081 ;
GO
EXEC sp_help doc_exe ;
GO
DROP TABLE doc_exe ;
GOsql