How to Insert Null Values into a Table in SQL Server

SQL Server Query to Insert Null Values into a Table

CREATE TABLE CUSTOMERS ( CID INT PRIMARY KEY,
CNAME VARCHAR(15), GENDER VARCHAR(3),
SAL DECIMAL(10,2), UNIQUE(CNAME));

INSERT CUSTOMERS VALUES(1,'JAN','M',10000.15);

--Inserting Blank value and a Null Value into a Column with UNIQUE Constraint.

INSERT CUSTOMERS VALUES(2,'','F',20000.25);

INSERT CUSTOMERS VALUES(3,NULL,'F',30000.35);

SELECT*FROM CUSTOMERS;

DROP TABLE CUSTOMERS;

NOTES :

-- Primary Key column will not Allow duplicate and Null Values.

-- Primary Key is a Table and Column level Constraint.

-- UNIQUE Constraint column will not allow duplicates but allows Null Values.

-- UNIQUE is a Table and Column level Constraint.

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