Integrity constraints means..? how many and what are they?
Answer Posted / firoz basha
Integrity constraint:- An IC is one which does not allow
invalid data entry into the database.
there are 3 types of Integrity constraints:
1. Entity Integrity COnstraint
primary key
unique key
Primary key does not allow null values and duplicate
values
unique key does not allow duplicate values.
unique key allows any number of null values (in case
of oracle)
unikey key allows only one null value. i.e, single null
value ( in the case of sql server 2000)
2. Domain Integrity Constraint
not null constraint
check constraint
rule constraint (in case of SQL SERVER 2000)
rule is an alternate to check constraint
3. Referential Integrity constraint
foreign key constraint
| Is This Answer Correct ? | 34 Yes | 1 No |
Post New Answer View All Answers
how to reject duplicates in source sequential file and if by filter option then where is that filter option in the sequential file.
Which is the best graph database?
Explain about ur projets on teradata???
Explain partial key?
Is redis in memory database?
Source File: Target EMPNO, SAL Empno, Format 101, 1000 101, 1000 101, 1100 101, 1000, 1100 101, 1000 101, 1000, 1100, 1000 101, 10000 101, 1000, 1100, 1000, 10000 102, 1100 102, 1100 102, 1300 102, 1100, 1300 102, 1200 102, 1100, 1300, 1200 102, 1500 102, 1100, 1300, 1200, 1500 How can i get that output using datastage(ETL) tool
During insert operation in Netezza Connector, if we give direct option as Yes , is there any issue?
Explain buffer manager?
What is a database string?
Explain data independence & its types.
can we delete autodiff back up that we have set through sql server agent.
Explain database partitioning.
Give the syntax of exception handling used in DBMS?
What is database client?
What is the best database?