I need to create a trigger function that would be called whenever i insert or delete data to my table.
Internally cache keeps the data in a global.
in the reverse way i can add data directly to the Global and i can view it in the table.
The trigger function works fine when i insert data using SQL Statement(Insert into).
But it fails to call when i add directly to the global.
so,how can i make triggers to be called when i add data to the Global directly. instead adding it using query (Insert into TABLE).
If you use the class to add data in the global, then you can use the Callback methods. For example %OnAfterSave does what you want.
On the other hand if you put data directly into the global then you will need some way to track when data is added. You can do this by writing your own agent or by doing what is adviced in this post: How can i make copy of a global automatically in my local system?
(this is the link referenced in that answer) http://docs.intersystems.com/cache20141/csp/docbook/DocBook.UI.Page.cls?KEY=GCDI_journal#GCDI_journal_util_ZJRNFILT
Related
I have a list of objects that will be saved locally as a .json file. The problem is that I don't want to update the .json file on each user modification of one of the lists' objects. Any window focus change will be sufficient to trigger the save() function to ensure data will not be lost.
How to implement this scenario or any other suggestions?
I'm a researcher in Loren Frank's lab at UCSF using datajoint and files in the nwb format. I made some changes to our code for defining entries in our ElectrodeGroup table, and was hoping to test those by deleting an entry in the table and regenerating it with the new code. I was able to delete the entry, but cannot repopulate it. In particular, when I run ElectrodeGroup.populate() or ElectrodeGroup.populate({"nwb_file_name": my_file_name}), no changes are made to the table. I confirmed that the electrode group I deleted and am trying to regenerate is defined in the original nwb file. I am seeking input on why the populate command seems to not be working here. Thanks in advance for any help!
This user also contacted our team through another channel. Sharing the solution below for future users, in reference to this schema. In short, the populate process is reserved for unique upstream primary keys.
Since the ElectrodeGroup's only upstream table dependency is Session, the make method will only be called if there are no electrode groups for that session. This is because from the perspective of DataJoint, the only 'guaranteed' knowledge about what should exist for this table is defined solely by the presence/absence of related upstream records. Since the 'new' primary 'electrode_group_name' attribute is defined by the ElectrodeGroup table itself, DataJoint doesn't know how many copies will be created by make, and so simply invokes make 1 time per Session, expecting the single make invocation to fully define all possible electrode_group_name values the table will use. If there is one value for that session, no work needs to be done, so no make() invocation occurs.
There are a couple possible solutions:
Model the electrode group explicitly, with a table defines the existence of an electrode group (e.g., ElectrodeGroupConfiguration). This ElectrodeGroup would then inherit primary keys from both Session and ElectrodeGroupConfiguration. The ElectrodeGroup make function would be adjusted to load that unique keys across upstream tables.
Adjust the make function to handle the partial insert/update case, and call the make function directly with the desired primary key when these kinds of 'abnormal' updates need to occur.
Method #1 is 'cleanest' w/r/t to the DataJoint data model (explicitly modeled data dependencies using make/populate), whereas #2 is slightly 'escaping' the DataJoint data model in a controlled way to achieve a desired schema/data result.
Is there a way of knowing that a table's data has changed (insert/update/delete) without using a trigger on that table? Perhaps a global trigger to indicate changes on a table?
If you want notification of changes, you will need to add a trigger yourself. Firebird 3 added a new feature to simplify identifying changed rows, the pseudo-column RDB$RECORD_VERSION. This pseudo-column contains the transaction that created the current version of a row.
Alternatively, you could try and use the trace facility to monitor for changes, but that is not an out of the box solution, as you will need to write the necessary logic to parse the trace output (and take things like transaction commit/rollback into account).
As stated in title, is it possible to take the actual "context" in which a trigger is being run and incorporate that variable into my trigger code itself?
i.e. I want to run a slight part of extra code for the trigger if its a newly inserted record, but not if its an existing one being updated.
Yes, you can use trigger context variables to examine the context in which the trigger is running. There are a variety of examples in that article. For your use case, you can use an if statement like this:
if (Trigger.isInsert) {
// do something on insert (and not on update)
}
Scenario: A computed property needs to available for RAW methods. The IsComputed property set in the model will not work as its value will not be available to RAW methods.
Attempted Solution: Create a computed column directly on the SQL table as opposed to setting the IsComputed property in the model. Specify that CodefluentEntities not overwrite the computed column. I would than expect the BOM to read the computed SQL field no differently than if it was a normal database field.
Problem: I can't figure out how to prevent Codefluent Entities from overwriting the computed column. I attempted to use the production flags as well as setting produce="false" for the property in the .cfp. Neither worked.
Question: Is it possible to prevent Codefluent Entities from overwriting my computed column and if so, how?
The solution youre looking for is here
You can execute whatever custom T-SQL scripts you like, the only premise is to give the script a specific name so the Producer knows when to execute it.
i.e. if you want your custom script to execute after the tables are generated, name your script
after_[ProjectName]_tables.
Save your custom t-sql file alongside the codefluent generated files and build the project.
In my specific case, i had to enable full-text index in one of my table columns, i wrote the SQL script for the functionality, saved it as
`after_[ProjectName]_relations_add`
Heres how they look in my file directory
file directory
Alternate Solution: An alternate solution is to execute the following the TSQL script after the SQL Producer finishes generating.
ALTER TABLE PunchCard DROP COLUMN PunchCard_CompanyCodeCalculated
GO
ALTER TABLE PunchCard
ADD PunchCard_CompanyCodeCalculated AS CASE
WHEN PunchCard_CompanyCodeAdjusted IS NOT NULL THEN PunchCard_CompanyCodeAdjusted
ELSE PunchCard_CompanyCode
END
GO
Additional Configuration Needed to Make Solution Work: In order for this solution to work one must also configure the BOM so that it does not attempt to save the data associated with the computed columns. This can be done through Model using the advanced properties. In my case I selected the CompanyCodeCalculated property. Went to advanced settings. And set the Save setting to False.
Question: Somewhere in the Knowledge Center there is a passing reference on how to automate the execution SQL Scripts after the SQL Producer finishes but I can not find it. Anybody now how this is done?
Post Usage Comments: Just wanted to let people know I implemented this approach and am so far happy with the results.