This thing is driving me crazy, and the error is quite meaningless to me:
Unable to update the EntitySet 'TableB' because it has a DefiningQuery and no element exists in the element to support the current operation.
My tables are put like this:
TableA
int idA (identity, primary key)
...
TableB
int idA (FK for TableA.idA)
int val
TableB has no defined primary key in the SQL server. The Entity Framework has imported the table and the association and set both fields as key. But it will output that error when I try to do an insert into the table!
What's wrong??
Edit:
As suggested by Alex, the solution was this:
Right click on the edmx file, select Open with, XML editor
Locate the entity in the edmx:StorageModels element
Remove the DefiningQuery entirely
Rename the store:Schema="dbo" to Schema="dbo" (otherwise, the code will generate an error saying the name is invalid)
Remove the store:Name property
I left the key as it was, since it was OK to me that both the columns are part of the key.
Well when a table is encountered without a PrimaryKey it is treated as a View.
And views show up in the EDMX file (open in an XML editor to see) in the StorageModel\EntitySet[n]\DefiningQuery element.
When you have a DefiningQuery the Entity becomes readonly unless you add modification functions. You need 3 modifications functions (aka Stored Procedures) one for each of Insert, Update and Delete.
But you have two options:
Change the key definion:
And convince the EF that what it thinks is a view is really a table
Or add the appropriate modification functions
In your case I recommend (1).
Just Add a primary key to the table. That's it. Problem solved.
ALTER TABLE <TABLE_NAME>
ADD CONSTRAINT <CONSTRAINT_NAME> PRIMARY KEY(<COLUMN_NAME>)
I was missing a primary key on my table and got this error message. One thing I noted was after I added the key to the table, I needed to clear the table from the edmx using the designer, save the edmx, then update it again to add the table back in. It wasn't picking up the key since it was already assigned as a view. This didn't require editing the edmx manually.
Add primary key to table, delete the model from the edmx model, then select update from database, build and run...... works
#Palantir. Verify that both of you tables have Primary Keys set, and be careful with multiple primary keys set in a table.
You need to manually open the .EDMX file in notepad or notepad++ or
in any text editor of your choice.
Locate the entry in edmx:StorageModels in file opened in step1.
Find the DefiningQuery element and remove this tag entirely.
Find the store:Schema="dbo" to Schema="dbo" (if you skip this step
it will generate error of the name is invalid).
Save and close the file.
Hope it will solve the problem.
Related
I am currently working on a database structure in SQLite Studio (not sure whether that's in itself important, but might as well mention), and error messages are making me wonder whether I'm just going at it the wrong way or there's some subtlety I'm missing.
Assume two tables, people-basics (person-ID, person-NAME, person-GENDER) and people-stats (person-ID, person-NAME, person-SIZE). What I'm looking into achieving is "Every record in people-basics corresponds to a single record in people-stats.", ideally with the added property that person-ID and person-NAME in people-stats reflect the associated person-ID and person-NAME in people-basics.
I've been assuming up to now that one would achieve this with Foreign Keys, but I've also been unable to get this to work.
When I add a person in people-basics, it works fine, but then when I go over to people-stats no corresponding record exists and if I try to create one and fill the Foreign Key column with corresponding data, I get this message: "Cannot edit this cell. Details: Error while executing SQL query on database 'People': no such column: people-basics.person" (I think the message is truncated).
The DDL I currently have for my tables (auto-generated by SQLite Studio based on my GUI operations):
CREATE TABLE [people-basics] (
[person-ID] INTEGER PRIMARY KEY AUTOINCREMENT
UNIQUE
NOT NULL,
[person-NAME] TEXT UNIQUE
NOT NULL,
[person-GENDER] TEXT
);
CREATE TABLE [people-stats] (
[person-NAME] TEXT REFERENCES [people-basics] ([person-NAME]),
[person-SIZE] NUMERIC
);
(I've removed the person-ID column from people-stats for now as it seemed like I should only have one foreign key at a time, not sure whether that's true.)
Alright, that was a little silly.
The entire problem was solved by removing hyphens from table names and column names. (So: charBasics instead of char-basics, etc.)
Ah well.
When using code first i have this scenario:
I have an existing database where tables are created with Code first.
Know suddenly there needs to be a change in the program and there is a new table that is related to the Primary table (with existing data in it).
Example there is a table "Package" and a the new table is "PackageState"
Steps
Create new domain Packagestate with some properties.
Add property packagestate (FK) in Package domain.(P) Note that the packagestate is required.
In the seeding class i add some data for the packagestate
From this point i have a problem, because the value is required, and the seeding method is only executed after update.
How do you solve this with code first?
Because it's possible that there is a new migration file as well.
I need some feedback on this thanks in advance!
You must make your foreign key nullable and update your database
after that you can run your seed.
and after all you should change your foreign key to not null.
Is it possible in SQLite to make an update instead of a delete within a trigger ?
I.e, I got these two tables:
CREATE TABLE author (authorid INTEGER PRIMARY KEY, temporal NUMERIC);
CREATE TABLE comment (id INTEGER PRIMARY KEY, text TEXT, authorid INTEGER, FOREIGN KEY(authorid) REFERENCES author(authorid));
When a deletion of an author is attempted and there's any comment referencing that author i want to update the "temporal" field and abort deletion.
I've tested different approaches with triggers but i have not found a way to do the two things, make the update and abort the delete. I can abort the delete (though in this case it's not necessary as it is enforced by the foreign key constraint) or make the update (though the delete will remove the record, so the update has no effect)
Aborting the deletion is possible only with using RAISE to generate an error, but this would have the consequence that any UPDATE gets rolled back.
You could make author a view and create several INSTEAD OF triggers that pass through most actions to the base table.
However, it would be much easier to handler the temporal logic in your application.
One of the database view I am trying to import using entity framework contains only two columns, one is an integer type of column and another one is an aggregate function. I am getting the following error.
The table/view does not have a primary key defined and no valid primary key could be inferred. This table/view has been excluded. To use the entity, you will need to review your schema, add the correct keys, and uncomment it.
I understand it is a known scenario and it can be fixed by either including a Key column in the view or modifying the edmx file manually.
I just wanted to know if there is some other solution other than the above two? I do not want to include an additional column in my query and making changes in edmx is not feasible as DB changes are very frequent and the edmx will be overwritten every time I update from db.
You can mark both properties as entity key directly in the designer but you must ensure that the composite value of these two properties will be always unique. If you cannot ensure that you must add another unique column anyway or you may have some other problems when working with such entity set.
I need to modify a column in a SQLite database but I have to do it programatically due to the database already being in production. From my research I have found that in order to do this I must do the following.
Create a new table with new schema
Copy data from old table to new table
Drop old table
Rename new table to old tables name
That seems like a ridiculous amount of work for something that should be relatively easy. Is there not an easier way? All I need to do is change a constraint on a existing column and give it a default value.
That's one of the better-known drawbacks of SQLite (no MODIFY COLUMN support on ALTER TABLE), but it's on the list of SQL features that SQLite does not implement.
edit: Removed bit that mentioned it may being supported in a future release as the page was updated to indicate that is no longer the case
If the modification is not too big (e.g. change the length of a varchar), you can dump the db, manually edit the database definition and import it back again:
echo '.dump' | sqlite3 test.db > test.dump
then open the file with a text editor, search for the definition you want to modify and then:
cat test.dump | sqlite3 new-test.db
As said here, these kind of features are not implemented by SQLite.
As a side note, you could make your two first steps with a create table with select:
CREATE TABLE tmp_table AS SELECT id, name FROM src_table
When I ran "CREATE TABLE tmp_table AS SELECT id, name FROM src_table", I lost all the column type formatting (e.g., time field turned into a integer field
As initially stated seems like it should be easier, but here is what I did to fix. I had this problem b/c I wanted to change the Not Null field in a column and Sqlite doesnt really help there.
Using the 'SQLite Manager' Firefox addon browser (use what you like). I created the new table by copying the old create statement, made my modification, and executed it. Then to get the data copied over, I just highlighted the rows, R-click 'Copy Row(s) as SQL', replaced "someTable" with my table name, and executed the SQL.
Various good answers already given to this question, but I also suggest taking a look at the sqlite.org page on ALTER TABLE which covers this issue in some detail: What (few) changes are possible to columns (RENAME|ADD|DROP) but also detailed workarounds for other operations in the section Making Other Kinds Of Table Schema Changes and background info in Why ALTER TABLE is such a problem for SQLite. In particular the workarounds point out some pitfalls when working with more complex tables and explain how to make changes safely.