topic table and primary key in Application Development and Automation Discussions

table and primary key

Former Member — Thu, 14 Feb 2008 15:08:33 GMT

is it nessary to give primary key in a table.and it should be define only at first position.plzz tell

Edited by: Alvaro Tejada Galindo on Feb 14, 2008 10:10 AM

Re: table and primary key

Former Member — Thu, 14 Feb 2008 15:11:37 GMT

Yes It is neccessary, we should give at first row only.

Re: table and primary key

Former Member — Thu, 14 Feb 2008 15:12:51 GMT

srinath:

I send you a mail yesterday...Please start using more describing titles or you're going to force me to delete your threads....Table is not a good title...I changed to table and primary key which is better...

Greetings,

Blag.

Re: table and primary key

Former Member — Thu, 14 Feb 2008 15:15:20 GMT

Yes otherwise you will get a syntax error.

Re: table and primary key

Former Member — Thu, 14 Feb 2008 15:17:21 GMT

hi,

s, primary key is mandatory.

it avoid the duplicate of data.for ex (student rollno, material no, employee id)

it should be a unique.

when you create the foreign key table . you want to refer only the primary key field of the reference table(checked table)

when you create the foreign key in the particular table before it should be one primary key.

you can create no of primary keys in one table.

by defaultly the one primary index should be created for that table.

regards

s.surender