What is a constraint. Types of constraints ?
Answers were Sorted based on User's Feedback
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 |
What is a sql statement?
What is coalesce sql?
What does seeding a database mean?
how to show all tables with 'mysql'? : Sql dba
Differentiate pl/sql and sql?
What is difference between cursor and ref cursor?
what are the different type of sql's statements ? : Sql dba
What are triggers, and when would you use them?
What are different types of sql commands?
what is the difference between cursor FETCH and FOR LOOP ?
3 Answers CG-VAK, Tech Mahindra,
What does stand for in sql?
How do you concatenate in sql?
Oracle (3259)
SQL Server (4518)
MS Access (429)
MySQL (1402)
Postgre (483)
Sybase (267)
DB Architecture (141)
DB Administration (291)
DB Development (113)
SQL PLSQL (3330)
MongoDB (502)
IBM Informix (50)
Neo4j (82)
InfluxDB (0)
Apache CouchDB (44)
Firebird (5)
Database Management (1411)
Databases AllOther (288)