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From Rick Hillegas <Richard.Hille...@Sun.COM>
Subject Re: How to retrieve the constraints associated to a table
Date Tue, 27 May 2008 13:46:19 GMT
fporto wrote:
> Narayanan-4 wrote:
>   
>> fporto wrote:
>>     
>>> Hi,
>>>  I'm receiving the following message when trying to drop a table:
>>>
>>> ERROR X0Y25: Operation 'DROP CONSTRAINT' cannot be performed on object
>>> 'SQL080516103912600' because CONSTRAINT 'SQL080525110646121' is dependent
>>> on
>>> that object.
>>>
>>> I would like to obtain the list of constraints associated to each of my
>>> tables.
>>> I've tried to use the Describe SQL command but it doesn't print
>>> constraint
>>> info.
>>>
>>> I've also tried to query system tables:sysconstraints, sysdepends but
>>> couldn't find the objects referred to in the msgs.
>>>
>>> Can someone there help me on this?
>>>
>>> cheers,
>>> Fabio.
>>>   
>>>   
>>>       
>> I tried this
>>
>>  select CONSTRAINTNAME from sys.SYSCONSTRAINTS,sys.systables where 
>> sys.systables.tablename='NARAYANAN' and 
>> sys.sysconstraints.tableid=sys.systables.tableid;
>>
>> Replace the tablename with the name of the table for which you want to 
>> find the constraints.
>>
>> Narayanan
>>
>>
>>     
>
> Thanks Narayanan,
>
>  in fact when I query the table sys.sysconstraints the refered constraint id
> is not there:
>
> select * from sys.sysconstraints where constraintid= 'SQL080525110646121';
> CONSTRAINTID                        |TABLEID                            
> |CONSTRAINTNAME                                                                     
                                           
> |&|SCHEMAID                            |&|REFERENCEC&
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> 0 rows selected
>  
> --
>
> It seems to me that there is some dangling reference. In fact, this error
> message appears when dropping the table databases:
>
> ij> describe databases;
> COLUMN_NAME        
> |TYPE_NAME|DEC&|NUM&|COLUM&|COLUMN_DEF|CHAR_OCTE&|IS_NULL&
> ------------------------------------------------------------------------------
> DBID                |DECIMAL  |0   |10  |4     |NULL      |NULL      |NO      
> HOSTSHORT           |VARCHAR  |NULL|NULL|20    |NULL      |40        |YES     
> IRI                 |VARCHAR  |NULL|NULL|100   |NULL      |200       |YES     
> DRIVERNAME          |VARCHAR  |NULL|NULL|150   |NULL      |300       |YES     
> DATABASETYPE        |DECIMAL  |0   |10  |2     |NULL      |NULL      |YES     
> SERVERID            |NUMERIC  |0   |10  |2     |NULL      |NULL      |YES     
>
> 6 rows selected
> ij> drop table databases;
> ERROR X0Y25: Operation 'DROP CONSTRAINT' cannot be performed on object
> 'SQL080516103925800' because CONSTRAINT 'SQL080525110734830' is dependent on
> that object.
>
> ij> select * from sys.sysconstraints where constraintid=
> 'SQL080525110734830';
> CONSTRAINTID                        |TABLEID                            
> |CONSTRAINTNAME                                                                     
                                           
> |&|SCHEMAID                            |&|REFERENCEC&
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> 0 rows selected.
>
> Fabio.
>   
Hi Fabio,

I think the problem is that you are trying to look up the constraint by 
its id rather than its name. The original error message was phrased in 
terms of the constraint's name, not its id. Here is the output of a 
little script which demonstrates the relationship between the error 
message and the columns in sys.sysconstraints:

ij> create table t( a int primary key );
0 rows inserted/updated/deleted
ij> create table s( a int references t( a ) );
0 rows inserted/updated/deleted
ij> drop table t;
ERROR X0Y25: Operation 'DROP CONSTRAINT' cannot be performed on object 
'SQL080527064442130' because CONSTRAINT 'SQL080527064442220' is 
dependent on that object.
ij> select c.constraintname, c.constraintid
from sys.sysconstraints c, sys.systables t
where t.tableid=c.tableid
and t.tablename='T';
CONSTRAINTNAME                                                                           
                                      
|CONSTRAINTID                       
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL080527064442130                                                                       
                                      
|6839c016-011a-2a9f-9dde-000000121ac0

1 row selected
ij> select c.constraintname, c.constraintid
from sys.sysconstraints c, sys.systables t
where t.tableid=c.tableid
and t.tablename='S';
CONSTRAINTNAME                                                                           
                                      
|CONSTRAINTID                       
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL080527064442220                                                                       
                                      
|2057c01b-011a-2a9f-9dde-000000121ac0

1 row selected

Hope this helps,
-Rick

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