I have this table used when a user writes a note.
When writing a note, the user specifies if a sell-department and/or a buy-department should receive the note.
Each user can create a Case (lets say its just a table with case_id and case_text). And the notes the users write are related to a case.
So the table NOTES is (postgres database) something like this:
ID
TEXT (the message itself)
USER_ID (the user that writes the note)
CASE_ID (the case_id for which the note is been written)
Short word about users:
There are "ordinary" users and those working on a department. This should not make big difference for the description here.
When an ordinary user writes a note, let's say he want both buy-department and sell-department to be included (being informed about the note/see the note).
What happens now is that there is another table called UserNotes. It looks like this:
ID
IS_READ
NOTE_ID
USER_ID
DEPARTMENT_ID
READ_AT_DATE
So ordinary user with id = 1 writes this note and in the code (as he tells sell and buy-departments have to be included) I search for all the users working at that specific sell-department and all those working at that specific buy-department. I then put all these users in the table UserNotes. With IS_READ false by default.
When a user in the specific sell-department reads the note, I will then change IS_READ for this user's entry in UserNotes.
This is how it works today. I don't think this is scalable. I'm already getting performance issues. I don't think it is important to know when a note has been read. So because of this I was thinking that maybe the following solution could work. Please have a look and tell me if it could be better and the current one or if you have some other suggestion please let me know:
I drop UserNotes table. I add a new filed in table Notes: READ_BY. Here I will update the field each time a user reads the note.
I don't know if I could use some postgres-specific thing, maybe making this field a json-string and searchable.
Related
Sql question.
I have a customer table with:
User id, name, email, phone
The customer can update their name, email and phone at anytime on an app.
How can I find out which user id had changes in name, email or phone number on a particular date?
Since your table doesn't store the date that they made the changes, you can't.
If you add a column with a datetime type (or whatever your specific database product provides) - you could call it LastModified or something like that - then the solution becomes trivial.
I'd give you a specific example, but because you didn't tell us what database engine you use, I can't guarantee to get the syntax right.
This is an issue with RDBMSes, you cannot as they generally store say a "photograph" of your data in time not a "film" of how it got there.
Based on the RDBMS you use, you can introduce an updated_at field which will hold when the last change happened to that row either from the "UPDATE" statement (say 'UPDATE phone=000, updated_at=now() WHERE user_id=999') or set it up to autoupdate see: create column for auto-date in postgresql
Im building a system for my company to keep track of internal orders, inbetween our warehouses, we have material that goes out warehouse 1 to warehouse 2 and we kind of lose track of how much of "x" is in warehouse 1 and how much in warehouse 2, so i want to implement this access db where a user fills a form and says: order 1: 500 of "x" order 2: 300 of "y". then another user fills an exit form where he says 1 of "x" going out, so i would need the program to keep track of total order and how much as gone out to fill order 1 and so on...
My idea here is to have both an order number and an id number for each of "x" everytime someoneone assembles 1 "x" they fill the form and print a label directly from the access (i have this part working already) while keeping a record of when it was assembled, who verified and what was verified (it will work as a quality control also).
What i dont know is how to program the db so when it reaches 500 of "x", the id number for "x" starts again from 1
This is the one major issue with my program right now, i'm not experienced in access db's or vba, but im getting there with a tip and a trick from here and there, so, no need to be careful with the technical language, i will google it if i have to :p
EDIT:
The table structure goes as follows:
1 table as the main table where I record the check that is made for every product, where I include the model of the product, the said ID that I want to reset after a number of products checked, and a concatenated field that includes most of this information to generate a qr code.
Then there is a table for the Order Number, which is connected to a form to record each new order with a date/time field, the order number itself and the number of products. This number of products must then be called from the code that will count how many products have been checked to date and keep the order number field updated so we can keep track of the order.
Then there is another minor table just to get values for the form, the product models
Thank you for your answers ;)
See this MSDN Documentation
Unfortunately in Access, you cannot 'reset' an ID field, unless you move the records to a newly created table and use that table for every 500 records.
As for the user control and login form, I'm afraid those are separate questions that must be asked in a different thread.
To get you started:
You can set the RecordSource of a form to a table, and when users make entries, the data will be saved to the table. You can also use a form with controls (text boxes, comboboxes, etc.) and create a button that runs a query to insert these records into a table.
The login piece - you can encrypt the database with a password. That may/may not be sufficient.
I would suggest you change your schema, if possible. Something like the following:
Orders
OrderID (Autonumber)
ProductID (link to your Products table)
QuantityRequested
Deliverables
DeliverableID (Autonumber)
OrderID (link to your Orders table)
SequenceNumber: in the BeforeInsert event set this value equal to:
DCount("*", "Deliverables", "OrderID=" & Me.OrderID) + 1
I'm assuming that your form has a control named OrderID that is bound to the OrderID field of the Deliverables table.
The code uses the DCount() function to get the count of all the other deliverables that have already been created for this order. If this is the first deliverable, DCount() will return 0. It then adds 1 to this count to get the sequence number of the next deliverable.
If the new SequenceNumber is greater than the quantity requested, you could display a message saying that the order has been filled and cancel the creation of the Deliverable record.
This is just one approach and it is not a complete solution. I'm assuming that once assigned a sequence number a deliverable cannot be deleted. You might need to make allowances for deliverables that get lost or damaged. You could incorporate a status field to the Deliverable table to deal with this, but you would still need to make a decision about what to do with the SequenceNumber.
I'm currently logging all actions of users and want to display their actions for the people following them to see - kind of like Facebook does it for friends.
I'm logging all these actions in a table with the following structure:
id - PK
userid - id of the user whose action gets logged
actiondate - when the action happened
actiontypeid - id of the type of action (actiontypes stored in a different table - i.e. following other users, writing on people's profiles, creating new content, commenting on existing content, etc.)
objectid - id of the object they just created (i.e. comment id)
onobjectid - id of the object they did the action to (i.e. id of the content that they commented on)
Now the problem is there are several types of actions that get logged (actiontypeid).
What would be the best way of retrieving the data to display to the user?
The easiest way out would be gabbing the people the user follows dataset and then just go from there and grab all other info from the other tables (i.e. the names of the users the people you're following just started following, names of the user profiles they wrote on, etc.). This however would create a a huge amount of small queries and trips to the database in a while loop. Not a good idea.
I could use joins to retrieve everything in one massive data set, but how would I know where to grab the data from in just one query? - there's different types of actions that require me to look into several different tables to retrieve data, based on the actiontypeid...
i.e. To get User X is now following User Y I'd have to get my data (User Y's username) from the followers table, whereas User X commented on content Y would need me to look in the content table to get the content's title and URL.
Any tips are welcome, thanks!
Consider creating several views for different actiontypeids. Union them to have one full history.
Hi does any one know how to check if a given DB object (Table/View/SP/Function) is used inside Oracle.
For example to check if the table "A" is used in any SP/Function or View definitions. I am trying to cleanup unused objects in the database.
I tried the query select * from all_source WHERE TEXT like '%A%' (A is the table name). Do you thing it is safe to assume it is not being used if it does not return any results?
From this ASKTOM question:
You'll have to enable auditing and then come back in 3 months to see.
We don't track this information by default -- also, even with auditing, it may be very
possible to have an object that is INDIRECTLY accessed (eg: via a foreign key for
example) that won't show up.
You can try USER_DEPENDENCIES but that won't tell you about objects referenced by code in
client apps or via dynamic sql
There's code in the thread for checking ALL_SOURCE, but it's highlighted that this isn't a silver bullet.
What do I gain by adding a timestamp column called recordversion to a table in ms-sql?
You can use that column to make sure your users don't overwrite data from another user.
Lets say user A pulls up record 1 and at the same time user B pulls up record 1. User A edits the record and saves it. 5 minutes later, User B edits the record - but doesn't know about user A's changes. When he saves his changes, you use the recordversion column in your update where clause which will prevent User B from overwriting what User A did. You could detect this invalid condition and throw some kind of data out of date error.
Nothing that I'm aware of, or that Google seems to find quickly.
You con't get anything inherent by using that name for a column. Sure, you can create a column and do the record versioning as described in the next response, but there's nothing special about the column name. You could call the column anything you want and do versioning, and you could call any column RecordVersion and nothing special would happen.
Timestamp is mainly used for replication. I have also used it successfully to determine if the data has been updated since the last feed to the client (when I needed to send a delta feed) and thus pick out only the records which have changed since then. This does require having another table that stores the values of the timestamp (in a varbinary field) at the time you run the report so you can use it compare on the next run.
If you think that timestamp is recording the date or time of the last update, it does not do that, you would need dateTime fields and constraints (To get the orginal datetime)and triggers (to update) to store that information.
Also, keep in mind if you want to keep track of your data, it's a good idea to add these four columns to every table:
CreatedBy(varchar) | CreatedOn(date) | ModifiedBy(varchar) | ModifiedOn(date)
While it doesn't give you full history, it lets you know who and when created an entry, and who and when last modified it. Those 4 columns create pretty powerful tracking abilities without any serious overhead to your DB.
Obviously, you could create a full-blown logging system that tracks every change and gives you full-blown history, but that's not the solution for the issue I think you are proposing.