SQL SERVER – Finding Tables with Primary or Foreign Keys

If you want to know if a table has a primary key or foreign key, you can find out this in many ways.

Let us create these tables

CREATE TABLE product_master
(
prod_id INT PRIMARY KEY,
prod_name VARCHAR(100),
price DECIMAL(12,2)
)
GO
CREATE TABLE product_details
(
prod_id INT,
sales_date DATETIME,
sales_qty INT,
sales_amount DECIMAL(16,2)
)
GO
CREATE TABLE company_master
(
compnay_id INT,
company_name VARCHAR(100),
address VARCHAR(1000)
)
GO

Now let us create foreign key:

ALTER TABLE product_details ADD CONSTRAINT ck_item FOREIGN KEY(prod_id) REFERENCES product_master(prod_id)

Now if you want to check if a table has a primary key, you can use the following methods

1) Use sp_pkeys system stored procedure

EXEC sp_PKEYS product_master

The result is

2) Use Objectproperty function

SELECT
*
FROM
INFORMATION_SCHEMA.TABLES
WHERE
OBJECTPROPERTY(OBJECT_ID(TABLE_NAME),'TABLEHASPRIMARYKEY')=1 AND
TABLE_TYPE='BASE TABLE'
ORDER BY
TABLE_NAME

if you want to check if a table has a foreign key, you can use the following method

SELECT
*
FROM
INFORMATION_SCHEMA.TABLES
WHERE
OBJECTPROPERTY(OBJECT_ID(TABLE_NAME),'TABLEHASFOREIGNKEY')=1 AND
TABLE_TYPE='BASE TABLE'
ORDER BY
TABLE_NAME

The result is

If you want to check for the tables that do not have primary key or foreign key, you can use the following method
SELECT
*
FROM
INFORMATION_SCHEMA.TABLES
WHERE
OBJECTPROPERTY(OBJECT_ID(TABLE_NAME),'TABLEHASPRIMARYKEY')=0 AND
OBJECTPROPERTY(OBJECT_ID(TABLE_NAME),'TABLEHASFOREIGNKEY')=0 AND
TABLE_TYPE='BASE TABLE'
ORDER BY
TABLE_NAME

The result is

Reference: Pinal Dave (http://blog.sqlauthority.com)