SQL NOT NULL Constraint

Anonymous User 1723 03 Nov 2015

what is NOT NULL Constraint in sql server .

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Updated 03 Nov 2015

1 Answers

Anonymous User 03 Nov 2015 Accepted Answer

The NOT NULL constraint enforces a column to NOT accept NULL values.

The NOT NULL constraint enforces a field to always contain a value. This means that you cannot insert a new record, or update a record without adding a value to this field.

The following SQL enforces the "U_Id" column and the "LastName" column to not accept NULL values:

CREATE TABLE Users
(
U_Id int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255)
)
--when we want insert null value lastname get error
insert into Users(U_Id,LastName,FirstName,Address,City)
 values(1011,null,'Ravi','mumbai','thane')

When I insert lastname null get error.

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