Interested to Buy Any Domain ? << Click Here >> for more details...
does PHP support foreign key and Rollback?yes or not.if not
then why. how will you done these concept in php?
- 1 Answers
- 6310 Views
- Avanigoradia, Primus Global, I also Faced
- E-Mail Answers
Answer Posted / praveen
PHP supports Foreign Keys in InnoDB Storage Engine in
version and above 4.0. It checks the foreign key referential
integrities on Delete and Select statements. If you strictly
needed the foreign keys and speed is not a concern then you
can create table structures using InnoDB Storage Engine.
Where as MyISAM Storage Engines does not allow foreign key
concept. But it will parse the table that contains foreign
keys but wont check the referential integreties. So it is
the job of the designer/programmer to check the desired key
and its dependency in multiple tables.
Let us suppose you have a field F1(primary)in Table1 and
this field is referenced in another tables denoted as (F2,
F3) in tables Table2, Table3......(as a foreign key)
and when you want to perform a DELETE operation/query based
on field F1, then
First you need to write a query to Delete the specified row
in Table1
and you also need to write a query to Delete all
dependent/referenced rows in other tables Table2, Table3...
| Is This Answer Correct ? | 6 Yes | 0 No |
Post New Answer View All Answers
How long does a php session last for?
What is static variable in php?
In PHP, fgets() is used to read a file one line at a time. State Whether True or False?
Why is facebook still using php?
What is the use of nl2br() in php?
What is preg_match?
What is meant by pdo in php?
Why is node js better than php?
Is it more secure to use cookies to trfer session ids?
What does session start do in php?
Tell me what is the difference between ereg_replace() and eregi_replace()?
When use javascript vs php?
Do you know what is the use of the function 'imagetypes()'?
Explain the different types of errors in php.
Tell me how can we get the error when there is a problem to upload a file?
