I have 3 tables that form a many to many relationship as illustrated in the following image.
How can I save an entry in the UsersByCompanies table between company number 1 and user number 2, following the following rules:
when we create a new entry between a user and a company, the IsEnabled attribute in UsersByCompanies must be set to 1 and any other rows where Companies.CompanyCode = 1 and Users.IDNumber = 2 must have their IsEnabled Attribute set to 0.
The DateCreated attribute in the new row must have the current date.
Sounds like you need an Insert Trigger and some default values:
When you insert into UsersByCompanies, use a Default Value on the IsEnabled column, and set an insert trigger function to perform an update to reset the IsEnabled attributes as you require.
Likewise, use a default value of getdate() for the DateCreated attribute.
Related
I currently have a select list with the values: 1, 2, 3, 4 & 5. These correspond to a column in table "DVD" called "DVDID", and these are the only values in this column in the table.
In the table "DVDCOPY" records exist containing the all DVDIDs (1,2,3,4,5) with a different DVDCOPYID.
E.g. a record from the DVDCOPY table is:
DVDCOPYID DVDID DISCCONDID
1 1 1
My question is, how can I make it so that once a DVDID is selected from the select list, the DVDCOPYID changes dynamically based on this selection? E.g. once 1 is selected in the DVDID select list, the value for DVDCOPYID also changes to 1 automatically.
My form currently looks like this, if this helps:
APEX Form
You have to use dynamic actions and PL/SQL. Create a hidden form element which allows for element changes (no session protection enabled). Create a new dynamic action in your form guiding to the select list and using the onchange event. Your dynamic action contains two steps: first set the hidden form element to the value of your select list. Second: execute a PL/SQL statement (UPDATE DVDCOPYID SET ... = :NEW_HIDDEN_ELEMENT WHERE ID = ...).
Let's say I have a column to store the creation time of the record, like a timestamp with DEFAULT CURRENT_TIMESTAMP. After inserting, the Model doesn't contain the value set by the database (the value is null).
Is the only way to get such info to execute myself an extra SELECT query after saving?
Thanks.
According to this page of documentation: http://javalite.io/autogenerated_fields you can create two columns: created_at and updated_at.
Data in these columns will be automatically maintained by the framework. If the column value is NULL, then the respective attribute value will also be null
I want to make filtration on a column after selecting a specific value of another column in the same table, I tried to use #... special character followed by the column's name to get the address of this value.
My SQL statement is like the following :
SELECT ATTRIBUTE FROM TABLE WHERE FIELD = '#FIELDNAME';
If I used a specific value instead of #FIELDNAME, it will work properly but it will be static but I need it to be dynamic based on the selected value.
Create another table which will have the list of values that are in the FIELDNAME and give each record a unique id ,then retrieve the value depending on what you have selected by the name of the new table's field preceded by '#...'
I don't know if that what are you looking for, please let me know.
If no triggers are allowed, do you have any date/time column in the table? Is it possible to have that extra column anyway to see the time of a newly inserted row?
You may have to check the lastest row entered, save its field value into a variable. Then do the select based on the variable value.
Based on the vague last row id you could try the following (it's not pretty). But again, if you have date/time that's more accurate.
select attribute from table
where field = (select field from table
where rowid =(select max(rowid) from table))
;
upate
Do you have the priviledge to set up your insert command as below:
insert into table (id, col1, col2,...) values (1,'something', 'something',...)
returning id into variable; -- you may either save field or id depending on your table
Then you may use this variable to select the records you want.
I added some rows into the table manually and also I set up the ID (auto_increment) manually. Now when I try to add new row through my app into DB table, to DB table I am getting the error , that the created ID value already exist.
How can I set manually the next ID value (for example, in table I have to IDs, so how to tell to PostgreSQL, that the next ID should be counted since the number 3)?
http://www.postgresql.org/docs/current/static/functions-sequence.html
select setval('sequence-name', <new-value>);
You can get the sequence name from the the table definition:
id | integer | not null default nextval('id_seq'::regclass)
In this case the sequence is named 'id_seq'
Edit (10x to #Glenn):
SELECT setval('id_seq', max(id)) FROM table;
I think there is a simpler way:
ALTER SEQUENCE "seq_product_id" RESTART WITH 10
I have a table where the results are sorted using an "ORDER" column, eg:
Doc_Id Doc_Value Doc_Order
1 aaa 1
12 xxx 5
2 bbb 12
3 ccc 24
My issue is to initially set up this order column as efficiently and reusably as possible.
My initial take was to set up a scalar function that could be used as a default value when a new entry is added to the table:
ALTER FUNCTION [dbo].[Documents_Initial_Order]
( )
RETURNS int
AS
BEGIN
RETURN (SELECT ISNULL(MAX(DOC_ORDER),0) + 1 FROM dbo.Documents)
When a user wants to permute 2 documents, I can then easily switch the 2 orders.
It works nicely, but I now have a second table I need to set up the same way, and I am quite sure there is a nicer way to do it. Any idea?
Based on your comment, I think you have a very workable solution. You could make it a little more userfriendly by specifying it as a default:
alter table documents
add constraint constraint_name
default (dbo.documents_initial_order()) for doc_order
As an alternative, you could create an update trigger that copies the identity field to the doc_order field after an insert:
create trigger Doc_Trigger
on Documents
for insert
as
update d
set d.doc_order = d.doc_id
from Documents d
inner join inserted i on i.doc_id = d.doc_id
Example defining doc_id as an identity column:
create table Documents (
doc_id int identity primary key,
doc_order int,
doc_value ntext
)
It sounds like you want an identity column that you can then override once it gets it initial value. One solution would be to have two columns, once call "InitialOrder", that is an auto-increment identity column, and then a second column called doc_order that initially is set to the same value as the InitialOrder field (perhaps even as part of the insert trigger or a stored procedure if you are doing inserts that way), but give the user the ability to edit that column.
It does require an extra few bytes per record, but solves your problem, and if its of any value at all, you would have both the inital document order and the user-reset order available.
Also, I am not sure if your doc_order needs to be unique or not, but if not, you can then sort return values by doc_order and InitialOrder to ensure a consistent return sequence.
If there is no need to have any control over what that DOC_ORDER value might be, try using an identity column.