does DB2 support enums? I didn't really find anything online.
The Query doesn't work:
create table prototype.test(id int not null primary key, level ENUM('upper', 'lower') not null);
Thanks in advance!
You can create a check constraint for that.
alter table prototype.test add constraint checklevel check (level in ('upper', 'lower'));
Or you can include this in the create table:
create table prototype.test(
id int not null primary key,
level varchar(5) check (level in ('upper', 'lower')
);
No DB2 does not support ENUMS. The are some database which I am aware of which suports Enums is MySql and Postgresql but DB2 for sure does not support it.
Related
I want to create a table bar with a named foreign key constraint backed by a named index. I would like to do that with an inline definition in the create table DDL statement. When looking at the Oracle 19 SQL Language Reference it looks like Oracle should support doing this inline.
When executing the following statements...
create table foo (
id number not null primary key
);
create table bar (
id number not null primary key,
nick varchar2(16) not null constraint foo_nick_ck unique using index,
foo_id number not null constraint foo_fk references foo using index
);
Oracle will respond with [42000][907] ORA-00907: missing right parenthesis and point at the position just before the using index on the last line. If I remove using index it works (but without index being created of course). I've kept the column nick as an example of where it works to create the backing index inline, but for a unique constraint instead of a foreign key constraint.
I am aware that a workaround is to create the backing index in a separate DDL statement, but I would very much like to have it neat and tidy inline.
I am aware that a workaround is to create the backing index in a separate DDL statement, but I would very much like to have it neat and tidy inline.
Unfortunately the syntax does not exist to create indexes inline.
The USING INDEX clause is syntactic sugar: Oracle creates indexes to enforce Primary Key and Unique constraints regardless of whether we include that clause (*). This is because an index is necessary to Oracle's implementation of unique constraints. But there is no such need for an index to enforce a foreign key, it's just desirable.
(*) Unless there's an existing index on the constrained column(s) which Oracle can use.
As per Oracle documentation:
You can specify the using_index_clause only when enabling unique or
primary key constraints
You cannot specify this clause for a NOT NULL, foreign key, or
check constraint.
How do I make a non-partition field of the table mandatory in Cassandra? I can't find anything in the documentation unfortunately
There isn't any NULL or NOT NULL constraints as you'd find in a relational database. The only requirement is to have a primary key.
I am new to SAP PowerDesigner I am trying to created tables and link them together to get the DB model and I am having difficulties on enabling Auto increment for the primary Key column of tables. Can someone please guide me
I have looked online and there was mentioning of check marking something called as Identity. But I do not see that option on Column properties.Image2
Image1
Which version of Oracle are you using?
Oracle 12+ supports identity columns. In PowerDesigner, the Identityoption is available in the Oracle tab on the Column, when the DBMS for the Physical Data Model is ORACLE Version 12c.
create table CONTACTS (
ID int
generated always as identity ( start with 1 nocycle noorder) not null,
NAME varchar(100) not null,
constraint PK_CONTACTS primary key (ID)
);
For previous versions of Oracle, the autoincrement was implemented with sequence, and triggers. See this page of PowerDesigner online documentation for example.
Description
Hi, so I am looking at a legacy database that includes multiple translation tables for existing tables.
So there is a laws table, but then there is also a translation_laws table:
Laws (law_id, inForceDate, type, etc)
Translation_Laws (law_id, lang_code, translation)
There is also a law_type table:
Law_Type (law_type_id, description, isDecreed, etc.)
Translation_Law_Type(law_type_id, lang_code, translation)
So, with the following scheme referential integrity is maintained, but you end up with multiple translations tables.
I would prefer to make one table with the following format:
translations(table_name, id, lang_code, translation)`
This would basically be like bundle, key, lang_code, label. I could also combine bundle+key+lang_code into one varchar key: bundle.key.lang_code.
However, I don't see much of a way to define a relationship in Oracle SQL.
Questions:
Any Ideas how to define a relationship while using Integer IDs??
Would it be so bad to NOT to define a relationship in the database?
Only solution I can think of would be to try add a String foreign key to every table needing a translation (aaa.bbb.ccc.ddd) that is unique.
Update
Currently I have done away with the official relationships in the DB and made the following type of schema:
CREATE TABLE TRANSLATIONS(
DESCRIPTION_ENTITY VARCHAR(30) NOT NULL,
DESCRIPTION_COLUMN VARCHAR(30) NOT NULL,
KEY_OR_ID VARCHAR(30) NOT NULL,
LANG_CODE VARCHAR(2),
TEXT CLOB,
-- Legacy are To be able to cross check using columns - but not needed
LEGACY_TABLE VARCHAR(30) NOT NULL,
LEGACY_COLUMN VARCHAR(30) NOT NULL);
ALTER TABLE TRANSLATIONS
add CONSTRAINT UNIQUE_COMBINATION UNIQUE (DESCRIPTION_ENTITY, DESCRIPTION_COLUMN, KEY_OR_ID, LANG_CODE);
CREATE INDEX ind_description_entity ON TRANSLATIONS (DESCRIPTION_ENTITY);
CREATE INDEX ind_description_column ON TRANSLATIONS (DESCRIPTION_COLUMN);
CREATE INDEX ind_key_or_id ON TRANSLATIONS(KEY_OR_ID);
CREATE INDEX ind_lang_code ON TRANSLATIONS(LANG_CODE);
insert into TRANSLATIONS(DESCRIPTION_ENTITY, DESCRIPTION_COLUMN, KEY_OR_ID, LANG_CODE, TEXT, LEGACY_TABLE, LEGACY_COLUMN)
select 'LAW','TITLE', LAW_CODE, LANG_CODE, LAW_TITLE,
'LAW_TRANS','TITLE'
from LAW_TRANS where TITLE is not null;
Personally, I don't think there is anything wrong with not defining a relationship in a DB. At a massive investment bank where I was working before our Oracle specialists NEVER defined the relationships for performance reasons.
The basic question for your setup is, do you need a defined amount of languages or do you have to be flexible with adding languages later? If not, your approach is almost too flexible. Just adding different rows with the translation into the Laws table would be much more performant if you know you only every need 4 different languages.
Alternatively, you could just build a lock-up table:
original-string -> translated-string
And you can ignore the table name completely.
In MS SQL Server it is possible to create a foreign key with ON UPDATE CASCADE option, so whenever you update one of the columns in the primary key, the foreign keys in other tables will also be update by the DBMS.
So, how to do it in Oracle?
Oracle does not allow a Foreign Key constraint with “ON UPDATE CASCADE”.
Here are a couple of options you have.
Create the Foreign Key, and create an “On Update” trigger.
Make use of the package below (needs to be installed in the db).
http://tkyte.blogspot.com/2009/10/httpasktomoraclecomtkyteupdatecascade.html
Let me know if you have additional questions or need more information.
Would a database trigger do the job for you ?
Here is the Oracle doc on the subject of Data Integrity for 11g (just incase you were interested).
You can't use on update cascade, but you can create a trigger that will resolve the issue:
create table tab1(
pk int PRIMARY KEY,
aa int);
create table tab2(
pk int PRIMARY KEY,
tab1_pk int,
FOREIGN KEY(tab1_pk) REFERENCES tab1(pk));
------------------------------------------
create or replace trigger tab1_pkUpdate
after update of pk on tab1
for each row
begin
update tab2 s
set s.tab1_pk = :new.pk
where s.tab1_pk = :old.pk;
end;
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