Every day I want to track how many "clicks"(int) a certain object in my database gets.
Now an int in the object called clicks obviously wouldn't help since I couldn't track the date of the clicks.
What way would be the smartest to store the daily clicks?
Keep the VisitedDate column in your tracking table.
RecordID INT Identity
ItemID INT
VisitedDate DateTime
IPAddress varchar(30)
Once you have the records, you can query and get the results for visits on a specific day/ month etc...
Create a table as Shyju suggests (ip address is optional), and yes it will grow fast but if it becomes a problem you can rollup the data to a weekly (or monthly, or yearly) rollup table where it stores the total for that item, for that time period.
Best to always initially store the data at this lowest-level and roll up/archive to summary tables as needed down the road, because if you store the data initially at the roll up level you have lost that detail forever - tracking at the detail level keeps all your options open.
There are workarounds for performance if you need them, there are no workarounds to recreate data you never stored.
I insert or update on the go, on the clicks table.
Clicks
(Product_id | Vendor_id | User_id)[unique] | Clicks | Created_at
Insert if the (Product_id | Vendor_id | User_id) combintaion does not exist. Update (+1 clicks), if that combination already exists.
I wouldn't worry about the performance right now, during the early stage.
If you still worry about it,
Use a javascript request and write the (Product_id | Vendor_id | User_id)[unique] | Clicks | Created_at into a textfile, onclick.
In the EOD, load the information in the file into clicks table.
Related
Let me describe briefly the table structures:
Customer Table
id | name | address_line_one | address_line_two | contact_no_one
SaleInvoice Table
id | id_Customer (Foreign Key) | invoice_no
If I have to print a Sale invoice, I have to use the Customer information (like name, address) from the Customer table.
Assume that after a year, some customer data changes (like name or address), and I update the new data in my customer table. Now, if the customer asks for an old invoice, it will be printed with the new customer data which shall be legally wrong.
Does that mean, I have to create
name_customer
address_line_one_customer
...
and all these fields in the Sale Invoice table too?
If yes, is there a better way to get data from these fields in Customer table to the Sale Invoice table then to write a SQL query to get the values and then set the values?
This is really up to you. In some cases, where it is a legal document, you will save all the details so that you can always bring it up the way it was created. Alternatively if you are producing pdf invoices then save them to be 100% sure.
The other alternative is to create a CustomerHistory table, so that past versions are always saved with a date range, so that you can go back to the old version.
It depends on the use cases, but those are your main options.
It sounds like a problem easily solved by placing the Employee table in version normal form (VNF). This is actually just a flavor of 2nf but done in a way that provides the ability to query current data and past data using the same query.
A datetime parameter is used to provide the distinction. When the value is set to NOW, the current data is returned. When the value is set to a specific datetime value in the past, the data that was current at that date and time is returned.
A brief discussion of the particulars can be found here. That answer also contains links to more information if you think it is something that would work for you.
(Before that, i apologize for my bad English)
I have study cases like this:
I am currently having a trouble with my Web Application. I made a Web application for a certain company. I made the app using CodeIgniter 3.
I built the database using Maria DB. For the id in each table, i am using Auto-increment id for my application database for each table. I usually deploy the web app to the cloud server (sometimes the company have their own dedicated server, but sometimes haven't ). One day, there is a company that they don't want to deploy the app that i have made before to the cloud ( for the security purposes they said ).
This company wanted to deploy the app to the employee's PC personally in the office, while the pc for each employee not connected to each other ( i.e stand alone pc/personal computer/employee's Laptop ). They said, for every 5 months, they would collect all of the data from employee's personal computer to company's data center, and of course the data center are no connected to the internet. I told them that's not the good way to store their data. ( because the data will be duplicate when i am trying to merge all of the data into one, since my column id for every table are in auto-increment id, and it's a primary key). Unfortunately, The company still want to kept the app that way, and i don't know how to solved this.
They have at least 10 employees that would used this web app. According that, I have to deploy the app to the 10 PC personally.
Additional info : Each employee have their own unique id which they got from the company, and i made the auto_increment id for each employee, just like the table below:
id | employee_id | employee_name |
1 | 156901010 | emp1
2 | 156901039 | emp2
3 | 156901019 | emp3
4 | 156901015 | emp4
5 | 156901009 | emp5
6 | 156901038 | emp6
The problem is whenever they fill the form from that application, some of the table are not stored the employee's id but the new id that come from increment id.
For example electronic_parts table. They have the attribute like below:
| id | electronic_part_name | kind_of_electronic_part_id |
if the emp1 fill the form from the web app , the table's content would like below.
| id | electronic_part_name | kind_of_electronic_part_id |
| 1 | switch | 1 |
and if the emp2 fill the form from the web app , the table's content would like below.
| id | electronic_part_name | kind_of_electronic_part_id |
| 1 | duct tape | 10 |
When i tried to merge the contents of the table into the data center it would falling apart because the duplicate id.
It's getting worst when i think about my foreign key in other tables.. like for example the customer_order table.
The table for customer_order column looks like below (just a sample, not the actual table, but similar).
|id | customer_name | electronic_parts_id | cashier(a.k.a employee_id, the increment id one, not the id that employee got from a company as i described above ) |
| 1 | Henry | 1 | 10 |
| 2 | Julie | 2 | 9 |
Does anyone know how to solved this problem ? or can someone suggest/recommend me some good way to solved this ?
NOTE: Each Employees have their own database for their app, so the database is not centralized, it's a stand-alone database, that means, i have to installed the database to the employee's pc one by one
This is an unconventional situation and you can have an unconventional solution.
I can suggest you two methods to solve this issue.
Instead of using autoincrement for primary key generate a UUID and use it as the primary key. Regarding the probability of duplicates
in random UUIDs: Only after generating 1 billion UUIDs every second
for the next 100 years
In CodeIgniter you could do this with the following code snippet.
$this->db->set('id', 'UUID', FALSE);
This generates a 36 characters hexadecimal key (with 4 dashes
included).
ac689561-f7c9-4f7e-be94-33c6c0fb0672
As you can see it has dashes in the string, using the CodeIgniter DB
function will insert this in the database with the dashes, it still
will work. If it does not look at clean, you could remove and
convert the string to a 32-char key.
You can use the following function with the help of [CodeIgniter
UUID library][1].
function uuid_key {
$this->load->library('uuid');
//Output a v4 UUID
$id = $this->uuid->v4();
$id = str_replace('-', '', $id);
$this->db->set('id', $id, FALSE);
}
Now we have a 32-byte key,
ac689561f7c94f7ebe9433c6c0fb0672
An alternate unconventional method to tackle the situation is by
adding function to log all Insert, Update, Delete queries processed
in the site to a file locally. By this way, in each local
implementation will generate a log file with an actual list of
queries that modify the DB over time in the right sequential order.
At any point in time, the state of the database is the result of the
set of all those queries happened in the past till that date.
So in every 5 months when you are ready to collect data from
employees personal computer, instead of taking data dump, take this
file with all query log.(Note: Such a query log won't have
auto-increment id as it will be created only in the real time when
it is executed towards a Database. )
Use such files to import data to your datacenter. This will not
conflict as it will generate autoincrements in your data center in
real time. (Hope you do not have to link your local to data center
at any point of time in future)
[1]: https://github.com/Repox/codeigniter-uuid
Is that id used in any other tables? It would probably be involved in a JOIN. If so, you have a big problem of unraveling the ids.
If the id is not used anywhere else, then the values are irrelevant, and the rows can be renumbered. This would be done (roughly speaking) by loading the data from the various sources into the same table, but not include the id in the load.
Or, if there is some other column (or combination of columns) that is UNIQUE, then make that the PRIMARY KEY and get rid of id.
Which case applies? We can pursue in more detail. Please provide SHOW CREATE TABLE for any table(s) that are relevant.
In my first case (where id is used as a FK elsewhere), do something like this:
While inserting the rows into the table with id, increment the values by enough to avoid colliding with the existing ids. Then do (in the same transaction):
UPDATE the_other_table SET fk_id = fk_id + same_increment.
Repeat for each other table and each id, as needed.
I think your problem come from your database... you didn't design it well.
it's a bug if you have an id for two difference users .
if you just made your id field unique in your database then two employee wouldn't have a same id so your problem is in your table design .
just initiate your id field like this and your problem will be solved .
CREATE TABLE [YOUR TABLE NAME](
[ID] int NOT NULL IDENTITY(1,1) PRIMARY KEY,
....
Is it required for the id to be an integer? if not may be you can use a prefix on the id so the input for each employee will be unique in general. that means you have to give up the auto increment and just do count on the table data (assuming youre not deleting any of the records.)
You may need to write a code in PHP to handel this. If other table is already following unique/primary key based than it is fine.
You can also do it after import.
like this
Find duplicates in the same table in MySQL
I am going to be developing a multi-user web app where users will record every day whether or not they have completed various tasks. The tasks are repeated every day, eg: Every day XYZ needs to be done.
Not all users will have the same tasks to complete each day. There will likely be a database table containing all possible tasks. When a new user signs up on the web, they will select the tasks that apply to them by creating a profile for themselves.
Each day the user will then record whether or not they completed their respective tasks. Following that, there will be in depth reporting and historical stats not just on a users own task history,...but also globally to look for trends.
Im just looking for any suggestions on how to design the database (in general terms). Would it be ok to have a task table that contains all the tasks. Then when a new user creates their own profile online, a brand new table is created with their profile information and the tasks that they have selected. Each unique user profile table will then contain an ongoing history of tasks completed each day.
Or is there a better way to design this?
Edit: Or would a better idea to be to have something like the below:
Task history table:
PersonID | Date | Task1 | Task2 | Task3 | Task 4
001 | 24Jan15 | Complete | Complete | |
002 | 24Jan15 | | Complete | Complete | Not Complete
003 | 24Jan15 | Not Complete | | |
So there would be one table containing all the users (and the tasks they've chosen), another table containing all possible tasks, and lastly the above table recording the task history each day.
The only issue here is that not every task is applicable to every person. So there will be blanks. Not sure if that matters.
As you can no doubt tell, im a beginner. So any advice would be appreciated.
It is almost never a good idea to create new tables dynamically to hold subsets of the data. Data for different users should go in the same set of tables, with some field identifying the user. There is no good reason to have hundreds of tables that are all identical except that one is for some key value A, the next is for key value B, etc. Just add the key field to the table.
As a_horse_with_no_name says, numbered columns is a strong sign that you are doing it wrong. There are many reasons why this is a bad idea. Among them: If you have one column for each task, what happens when a new task is added? Instead of just adding a new record, now you have to add a new column to the table, and update all the existing records. Also, it makes queries very complicated. A query like "what tasks were done today" requires a separate test for every column, instead of one test on a single "task" column.
From what you've said, here's my first thought on how this should look:
Task table
(task_id, task_name)
This lists all the tasks of interest.
User table
(user_id, user_name)
This lists all the users.
Assigned_Task table
(user_id, task_id)
This relates users to tasks. There will be one record in this table for each task for each user. That is, if Alice is user 1 and she is supposed to do tasks 1, 2, and 3; and Bob is user 2 and he is supposed to do 2 and 4, then there will be records (1,1), (1,2), (1,3), (2, 2), and (2,4).
(Note: You might have an assigned_task_id field for this table to be the primary key, or the PK could be user_id + task_id, as that must be unique.)
Task_Status table
(user_id, task_id, task_date, completed)
This will have one record for each user/task combination, for each day. So after 30 days, if Alice has 3 tasks, there will be 3 x 30 = 90 records for her, 3 for each day times 30 days.
(You might have a task_status_id as the PK, or you might use user_id + task_id + task_date. Keys with more than 2 fields tend to be a pain so I'd probably create a task_status_id. Whatever.)
Any of these tables might have additional fields if there's other information you need. Like the User table might have employee number, phone number, department, etc.
Then a question like, "What tasks were not completed yesterday?" is easily answered with this query:
select user.name, task.name
from task_status
join user on user.user_id=task_status.user_id
join task on task.task_id=task_status.task_id
where task_date=#date
and completed=0
How many tasks were completed today?
select count(*)
from task_status
where date=#date and completed=1
Etc.
My database tables holds a number of keys (sensitive information) which are encrypted. These keys are associated with users via an ID field. At any time i may need to invalidate a user by updating their ID field making them no longer identifiable. However i don't want to completely remove the row from the database. Instead i would like to keep it for audit purposes.
Is there a common convention i can follow for this or is simply appending a string with some random content enough to the ID field being invalidated sufficient?
E.g
Table before invalidate request
| ID | KEY |
------------------------
| user123 | yiuy321ui |
Table after invalidate request
| ID | KEY |
--------------------------------------
| legacy_79878_user123 | yiuy321ui |
I would avoid using any ID field of any table dynamically. Not only does it defy convention and best practices, but you will likely break associations with other tables which lookup/join on that field. I suggest adding a simple boolean field to your table, and set that field true or false to maintain a users validity.
Updating the user ID is not really a very good way of doing this. What you want is to be able to say 'this user is not active' anymore, so it would seem to make sense to have an Active bit field on your user table.
You may need to update your code where it validates your user to check for 'active' users only, but this will be easier in the long run (and also make it easier to re-enable a user if you need to).
I want to write a timer that counts up, no preference of code, that has controls to start and stop the timer on my server, but displays the time on the clients computer. I can offer more information if needed.
Thanks!
What you need is a database. I'd go with MySQL (http://dev.mysql.com/downloads/mysql/), since it's good and free. If you're paying for hosting you might already have access to a database though.
Then you need some tables to store the necessary info. How you create them depends on your database, but I'll make a rough outline.
You'd typically have a customer table with info about your customer:
| Customer Id | Customer name | Contact person | Phone | E-mail |
Then a table for each of the project your doing for your customer (here you'll have a foreign key to the customer table):
| Project Id | Customer Id | Cost per hour | Estimated hours | Start date | Finish date |
And here's the table that will be updated whenever you start or stop working on the project. There will be a new row in this table every time you "stop the timer" on the project (project Id is a foreign key to the previous table. Customer id is optional, since you can get at the customer through the second table):
| Session Id | Project Id | Customer Id | Start | Stop |
Here "start" and "stop" are timestamps. Session id is an auto incremented id. Each time you start the timer, that corresponds to inserting a new row into the table with the current time in the start field. Each time you stop the timer, that corresponds to setting the current time in the stop field for the only row with the current project where the stop date is null.
When the customer wants to know the total time spent on the project so far, that's a matter of summing all the intervals (stop - start) on the projects.
To make use of any of this, you need to make a framework in some kind of programming language. I prefer perl myself, but php is probably your best bet, since it's well suited for these kinds of things.
It's hard to go into more specifics until you've made some design choices, but I hope this is enough to give you a general idea of how you can implement it.