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What is a constraint. Types of constraints ?
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Answer / sohail
Constraint is a restriction on table.There are two types of
constraints 1.ananymous constraint and 2.named
constraint.under named and ananymous constraints there are
1.primary key constraint
2.foreign key constraint
3. not null constraint
4. check constraint
5. unique constraint.
| Is This Answer Correct ? | 40 Yes | 10 No |
Answer / pavani
Constraint means it is rule which you want to apply on the
table. There are two types of constraints.
1. Column Constraints: Applicable for that column only.
2. Table Constraints: Applicable for more than one column.
Column Constraints:
a. unique b. not null c. primary key d. foreign key
e.default f. check
Table constraints:
a. unique b. primary key c. foreign key d. check
| Is This Answer Correct ? | 26 Yes | 5 No |
Answer / sujit.1551
constraint are nothing but a conditions,in other words
enforcing the business rules into the database.
types of constraits:
1)check constraint
2)unique constraint
3)primary key
4)foreign key
5)Not null
6)Default
| Is This Answer Correct ? | 20 Yes | 3 No |
Answer / samuvel
Constraint is a restriction on table
Types:
1)Column Constraints:applicable for column level
i)unique ii) not null
2)Table constraints:applicable for table level
1)primary key ii) foreign key d. check
| Is This Answer Correct ? | 8 Yes | 4 No |
Answer / ravi
constraints are two types
1.Rule based constraint
2.cost based constraint
| Is This Answer Correct ? | 0 Yes | 0 No |
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