how do you restrict number of rows for a particular value
in a column.For example:there is a table called
fruits,having apples,bananas ,papayas.I dont want to have
more than 100 apples in that table ,so how can u restrict
number of rows for apple to hundred?
Answers were Sorted based on User's Feedback
Answer / gk
We can use Check constraint to restict the values of any
column.
| Is This Answer Correct ? | 12 Yes | 3 No |
Answer / suresh babu
create check constraint is the best way to restrict the
limited number of entries,because the constraint won't take
a separate space,but Trigger required separate memory
space.perhaps the trigger got error,it would affect all
entries in table.
| Is This Answer Correct ? | 2 Yes | 1 No |
Answer / bikash khuntia
We have to create a trigger for that which is one of the
way for the solutuion as below:-
create or replace trigger trigger_name
before insert on table_name
for each row
DECLARE
v_count number;
begin
select count(apple) into v_count from table_name;
if v_count=100 then
raise_application_error('-20011','u cant insert more than
100 apples in the table');
end if;
end;
| Is This Answer Correct ? | 1 Yes | 1 No |
Answer / ashwin
You can create a sequence named seq_fruit as below .
create sequence seq_fruit
increment by 1
start with 1
maxvalue 100
minvalue 1
cycle
cache 10
if the current count ie currval of seq_fruit is 100 and
after this if u r inserting a new row in fruit table as
following
insert into fruit values(seq_fruit.nextval,30,40);
after the execution of this statement next value for apple
will be entered as 1 and not 101.
The cycle keyword will avoid the count of fruit column to go
beyond 100.
| Is This Answer Correct ? | 0 Yes | 1 No |
Explain character-manipulation functions?
I have a Employee table with columns ename,eid,salary,deptno. How to retrieve sum of salary for each deptno?
How many types of cursors are available in pl/sql?
Is big data nosql?
Is primary key a clustered index?
Why cross join is used?
I have a tablle like this: cust acc ----------- a 1 b 2 b 3 c 4 c 5 c 6 I Want below o/p: cust acc --------------- a 1 b 2|3 c 4|5|6 Please any one can you have any ideas share me. I have urgent requirement.
Hi all, i have a table as follows empid empname mgrid deptid 1 a 3 4 2 b 1 5 3 c 2 3 4 d 3 6 5 e 4 7 i want the output as empname mgrname a c b a c b d c e d
How do I access sql anywhere database?
How do I tune a sql query?
What is a join?Explain the different types of joins?
6 Answers Bank Of India, CitiGroup, Google, ICICI, Saama Tech, SkyTech, TCS,
What is the difference between subquery and correlated query?
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)