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From Rajesh Kartha <kar...@Source-Zone.Org>
Subject Re: Removing a constraint
Date Thu, 17 Mar 2005 23:15:26 GMT
Christian Rodriguez wrote:

>Hello everyone, 
>
>I have the following problem.
>
>1. I created a table that has a UNIQUE constraint.
>
>something like
>
>create table users (
>  ...
>  email VARCHAR(30),
>  constraint email_unq UNIQUE (email)
>);
>
>2. I drop the table and try to recreate it, but it complains that the
>constraint "email_unq" already exists in schema APP.
>
>3. Then I thought about removing the entire database by removing the
>entire database directory with operating system commands.
>
>4. I still get the same errror saying the constraint doesnt exist.
>
>So... how do I get rid of that constraint? How do I remove all
>constraints if I want to start from scratch again?
>
>Thanks!
>Xtian
>
>  
>
Hi ,
Dropping the tables should drop the constraints on it.

http://incubator.apache.org/derby/manuals/reference/sqlj28.html#DROP+TABLE+statement

I tried it and it works fine for me:

ij version 10.1
ij> connect 'jdbc:derby:testTSNEW';
ij> create table usr(user_name char(12), email varchar(30) not null, 
constraint email_unq UNIQUE (email));
0 rows inserted/updated/deleted
ij> select * from usr;
USER_NAME   |EMAIL                        
-------------------------------------------

0 rows selected
ij> drop table usr;
0 rows inserted/updated/deleted
ij> create table usr(user_name char(12), email varchar(30) not null, 
constraint email_unq UNIQUE (email));
0 rows inserted/updated/deleted
ij> insert into usr values('abc','abc@abcd.org');

Was the table successfully dropped in your case ?. Can you check the 
steps you performed again?
Any stack traces in the derby.log file ?

Regards,
Rajesh





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