What are constraints? Explain different types of
constraints?
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Answer / wishpreet kaur
constraints are the restictions or boundaries.
we can categorise the constraints into 3 categories:
1. object constraints: specify that some objects depends
entirely or partially on other objects.
2. dynamic constraints: specify relationship among states
and events.
3. functional constraints: specify relationship among
operations.
| Is This Answer Correct ? | 1 Yes | 1 No |
Answer / manikandan elangovan
Primary key
Foreign Key
Unique Key
Not Null
Check
default
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / rev
3 basic types
1.entity constraint:
check
not null
null
2.domain constraint:
unique
primary
composite primary key
3.referential constraint:
integrity
foreign
| Is This Answer Correct ? | 27 Yes | 28 No |
Answer / taru mathur
a constraint refers to a condition or a check that is
applied to a coloumn(field)or a set of coloumns in a table.
Their are mainly five types of constarints:
1. UNIQUE CONSTRAINT
2. PRIMARY KEY CONSTRAINT
3. DEFAULT CONSTRAINT
4. CHECK CONSTRAINT
5. FOREIGN KEY CONSTRAINT
| Is This Answer Correct ? | 5 Yes | 6 No |
Answer / k.swathi
constraint is a mechanism which is used to stop the data entered by the end user by implementing bussiness rules.
contraint are 6 types
1)unique
2)primary key
3)check
4)null
5)not null
6)foreign key(refferential key)
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / md. aftab alam
It is a part of the table definition that are used to limit the values entered into its columns.its type are
1. Not null
2. Unique
3. primary key
4. Ckeck
5. Reference key
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / kumarcsn
basically there are two types of constraints
1.TABLE LEVEL CONSTRAINTS
2.COLUMN LEVEL CONSTRAINTS
| Is This Answer Correct ? | 9 Yes | 11 No |
Answer / g.rajesh(m.tech)
constrain kis a rule.
types of constriants are
1.domain constrain:
eg:chjeck,default,not null.
2.entity constraints:
eg:primary key.
unique key
3.referential constrain:
eg:foreign key
| Is This Answer Correct ? | 7 Yes | 9 No |
Answer / henry
Constraints are used to restrict or protect the data and
accessing from the table
There are 5 types of constraints available,
That,
1.Primary-which is not allowed duplication and Null values
2.Unique-Which is also Not allowed duplication But It is
allowed one single null values
3.Foreign - Which is allowed duplication and Null values.
But It refers Value from primary Key table to its own table
Value.
4.Check Constratints
5.Not null
| Is This Answer Correct ? | 5 Yes | 8 No |
Answer / vijay
there are 5 types of constraints that is as follow...
1.primary key
2.not null
3.check
4.default
5.unique
this are constraints types........
| Is This Answer Correct ? | 0 Yes | 3 No |
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