Answer / vinod

Constraints are used to restrict the insertion of unwanted data.
Using constraints you can maintain data integrity by preventing invalid data being entered.

Constraints are Five type
Primary key
Unique Key
Foreign Key
Not Null
Check

Answer / mohan

Constraint is nothing but set of rules or restrictions on a column,in order to achieve business requirements.

There are five types of constraints,
they are
1.primary key
2.unique key
3.not null
4.check
5.foreign key

These constraints also called data integrity constraints.

Answer / awadhesh

You can place constraints to limit the type of data that can go into a table. Such constraints can be specified when the table when the table is first created via the CREATE TABLE statement, or after the table is already created via the ALTER TABLE statement.

Common types of constraints include the following:

NOT NULL Constraint: Ensures that a column cannot have NULL value.
DEFAULT Constraint: Provides a default value for a column when none is specified.
UNIQUE Constraint: Ensures that all values in a column are different.
CHECK Constraint: Makes sure that all values in a column satisfy certain criteria.
Primary Key Constraint: Used to uniquely identify a row in the table.
Foreign Key Constraint: Used to ensure referential integrity of the data.

Answer / pandia rajan

A constraint is a property assigned to a column or the set
of columns in a table that prevents certain types of
inconsistent data values from being placed in the column
(s). Constraints are used to enforce the data integrity.
This ensures the accuracy and reliability of the data in
the database

CONSTRAINT=The threat or use of force to prevent, restrict,
or dictate the action or thought of others.

there are 7 types of constraints are there and they are
grouped in to 4 types. They are

TYPES GROUP
1.DEFAULT = DOMAIN INTEGRITY
2.NOT NULL = DOMAIN INTEGRITY
3.CHECK = DOMAIN INTEGRITY
4.FOREIGN KEY = REFERENTIAL INTEGRITY
5.UNIQUE KEY = ENTITY INTEGRITY
6.PRIMARY KEY = DOMAIN INTEGRITY
7.RULE = USER DEFINED INTEGRITY

Answer / ns

constraints are like an a right or any event which can we
apply on our table or column, or its an rule of integrity
there is an types of constraint:-
1.primary key
2.foreign key
3.unique
4.check
5.default
6.not null

Answer / magesh manavalan

Types Of Constraints:

* Primary Key

* Foreign Key

* Default

* Unique Key

* Not NULL

* Check

Answer / rajesh

there r 33 constraints

Answer / lekhraj

Constraints are the way by Databse managing the data inegrity.

Types of constraint are:-
1)NOT Null
2)Default
3)Check
4)Rule
5)Primary
6)Unique
7)Foreign

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