What are constraints? Explain different types of
constraints?
Answers were Sorted based on User's Feedback
Answer / aravindu chowdary
CONSTRAINTS:
*It is a rule (or) restriction ,which is enforced during a
creation of table.
*constraints raises automatically at the time of
inertion,updation,deletion.
*constraints there are 3 types
1.Domain Integrity
* Not null:Donot allow null value.
* check: Limits the range of values or domain, checks
the values which a col can have
2.Entity Integrity
* Unique key:donot allow duplicate values, but allows
one null per col.Can have multiple unique constraints on a
table
* Primary key : Ensure no duplicate data and not allow
nulls.
3.Refrential Intrgrity
*Forgien key:Referntial integrity b/w 2 tables, one
table col values based on other table col values
Is This Answer Correct ? | 1 Yes | 4 No |
Answer / the smart one
constraint is something that is restricted or prohibited
for example.
1. Not driving with a license
2. partying after hours if 17 or younger.
Is This Answer Correct ? | 2 Yes | 6 No |
Answer / rohit
MySQL does not support the use of CHECK constraint
Is This Answer Correct ? | 4 Yes | 12 No |
Answer / annie choudhary
Constraints are things that are likely to go wrong. There
are three types.
Time constraints
Legal constraints
Finacial constraints
Is This Answer Correct ? | 15 Yes | 49 No |
Answer / mohib
there are two types of
constraints
1;holonomic
constraint
2;non-holonomic constraints
Is This Answer Correct ? | 21 Yes | 58 No |
Answer / napster da boss
these are the constarints or codes which an organisation
has to abide by. Not necessarily does any one have to abide
by these, however there are many biles like that can kinda
get peopel to abide by them u get me blud. Dun now this is
dab real macoy doe.
Vote YES for dis 1 if u r a real G u get me.
All ady everyday 2K8 get 2 know.
Is This Answer Correct ? | 15 Yes | 65 No |
Find 2nd Highest salery in emp table Select* from emp where &n= select * count from emp where (salery >=emp.salery) Enter n value 2 These query is correct or not. Tell me any other methods.
What are the recovery models in sql server 2000?
What is recompile sql server?
How to use old values to define new values in update statements in ms sql server?
can we give the identity for existing column of the table? (already table contains 10(1-10) unique randam records)
What are the different types of cursor?
What is the difference between value type and reference type?
What is difference between after and before?
When we are using this query to shrink the log file,what exactly it will execute internally? Do we lose any data when we run this script? which data it will truncate in the log file and where it is saved. Please let me know... USE DatabaseName GO DBCC SHRINKFILE(<TransactionLogName>, 1) BACKUP LOG <DatabaseName> WITH TRUNCATE_ONLY DBCC SHRINKFILE(<TransactionLogName>, 1) GO
What is the difference between an index and a unique index?
What is a field in a table?
There is a trigger defined for INSERT operations on a table, in an OLTP system. The trigger is written to instantiate a COM object and pass the newly insterted rows to it for some custom processing. What do you think of this implementation? Can this be implemented better?