AutoMigrate is not adding constraint UNIQUE for an existing column and that column doesn't have any duplicates.
Note. nothing shown using Debug mode.
any idea?
Related
I apologize if I repeat the question, but I did not find a similar one.
I have added a unique constraint on an already existent table. We use MariaDB.
I have used the annotation:
#Table(uniqueConstraints={#UniqueConstraint(name="autonomy_name_energyType", columnNames={"autonomy","name","energyType"})})
The unit tests pass, but in the DB I am still allowed to create duplicates.
Do I need an ALTER table too? By checking the table I can see there are no constraints added to it.
Thanks
As explained in these SO posts :
Unique constraint not created in JPA
#Column(unique=true) does not seem to work
An explicit alter table query is needed for ur constaints to take effect on the db level.
As an extra info, it would have worked if the table was being re-created via JPA. see :
Add a unique constraint over muliple reference columns
I have a migration script in between 2 different schema database. The script does 3 things:
Disable constraint
Insert record from old schema to new schema
Enable constraint
During enable constraint, it encouter ORA-02298 - Parent keys not found: at the following 2 tables:
ALTER TABLE COUNTRY ENABLE CONSTRAINT COUNTRY_FK1;
ALTER TABLE EMPLOYEE ENABLE CONSTRAINT EMPLOYEE_FK7;
Anything went wrong in the table structure definition of these 2 tables?
It appears you are migrating detail records without ensuring that all the foreign key values are present in the referenced tables. If this is the case then you need to migrate records from REGION#SOURCE_DB into REGION#TARGET_DB before you migrate the COUNTRY records.
I'm working on migrating all the tables in my schema to be partitioned tables. Since I'm on 11g instead of 12.2 I have to use DBMS_REDEFINITION. I've automated this with some Ruby code that executes the redefinition procedures for each table in my schema.
My issue is that after migrating, all of my non-nullable columns show NULLABLE - YES. This isn't actually true however, as I can check the constraints and there are check constraints defined for each of the columns that used to be NOT NULL, still enforcing the NOT NULL status. It seems like DBMS_REDEFINITION successfully copied the constraints, but it didn't reflect the NULLABLE status.
Is there a way to tell Oracle to get this back in sync?
I found the answer elsewhere:
https://dba.stackexchange.com/questions/55081/why-is-sqlplus-desc-table-not-showing-not-null-constraints-after-using-dbms-re
Oracle copies the constraints but never turns validate back on. You have to manually do that with:
ALTER TABLE <table_name> ENABLE VALIDATE CONSTRAINT <constraint_name>;
The diagram has over 40 tables, most of them have a primary key defined.
For some reason there is this one table, which has a primary key defined, but that's being ignored when I export the model to a DDL script.
This is the "offending" key (even though it's checked it is nowhere to be found on the generated DDL script):
Has anybody had the same problem? Any ideas on how to solve it?
[EDIT] This is where the key is defined:
And this is the DDL preview (yes, the primary key shows up there):
This is what happens if I try to generate the DDL for just that table (primary key still not generated):
I was finally able to identify and reproduce the problem.
It was a simple conflict of constraints.
Table MIEMBROS had a mandatory 1 to n relationship (foreign key) from another table on its primary key column and vice-versa (there was a foreign key on MIEMBROS against the other table's primary key).
This kind of relationship between two tables makes it impossible to add a record to any of them: The insert operation will return an error complaining about the foreign key restriction pointing the other table.
Anyway I realized that one of the relationships was 0 to n so I simply unchecked the "mandatory" checkbox on the foreign key definition and everything went fine.
So, in a nutshell: The Data Modeler "fails" silently if you are defining a mutual relationship (two foreign keys, one on each table against the other table) on non nullable unique columns, by not generating the primary key of one of the tables.
Such an odd behavior, if you ask me!
"This kind of relationship between two tables makes it impossible to add a record to any of them: The insert operation will return an error complaining about the foreign key restriction pointing the other table."
Actually, if you have deferred constraints, this is not impossible. The constraints can be enforced, for example, at commit time rather than immediately at insert time.
From the Data Modeler menu under File, I used Export -> DDL File. The keys appeared in the DDL, then when I went back to the diagram and did DDL Preview, it showed all the missing stuff.
I'm trying to create a constraint on the OE.PRODUCT_INFORMATION table which is delivered with Oracle 11g R2.
The constraint should make the PRODUCT_NAME unique.
I've tried it with the following statement:
ALTER TABLE PRODUCT_INFORMATION
ADD CONSTRAINT PRINF_NAME_UNIQUE UNIQUE (PRODUCT_NAME);
The problem is, that in the OE.PRODUCT_INFORMATION there are already product names which currently exist more than twice.
Executing the code above throws the following error:
an alter table validating constraint failed because the table has
duplicate key values.
Is there a possibility that a new created constraint won't be used on existing table data?
I've already tried the DISABLED keyword. But when I enable the constraint then I receive the same error message.
You can certainly create a constraint which will validate any newly inserted or updated records, but which will not be validated against old existing data, using the NOVALIDATE keyword, e.g.:
ALTER TABLE PRODUCT_INFORMATION
ADD CONSTRAINT PRINF_NAME_UNIQUE UNIQUE (PRODUCT_NAME)
NOVALIDATE;
If there is no index on the column, this command will create a non-unique index on the column.
If you are looking to enforce some sort of uniqueness for all future entries whilst keeping your current duplicates you cannot use a UNIQUE constraint.
You could use a trigger on the table to check the value to be inserted against the current table values and if it already exists, prevent the insert.
http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14251/adfns_triggers.htm
or you could just remove the duplicate values and then enfoce your UNIQUE constraint.
EDIT: After Jonearles and Jeffrey Kemp's comments, I'll add that you can actually enable a unique constraint on a table with duplicate values present using the NOVALIDATE clause but you'd not be able to have a unique index on that constrained column.
See Tom Kyte's explanation here.
However, I would still worry about how obvious the intent was to future people who have to support the database. From a support perspective, it'd be more obvious to either remove the duplicates or use the trigger to make your intent clear.
YMMV
You can use deferrable .
ALTER TABLE PRODUCT_INFORMATION
ADD CONSTRAINT PRINF_NAME_UNIQUE UNIQUE (PRODUCT_NAME)
deferrable initially deferred NOVALIDATE;