I have a business case I have not been able to solve yet. Actually I'm stuck with it lot.
I have huge organization with pretty vertical hierarchy.
As average people have 2 team members in their team and there is around 100+ levels from root to bottom (growing constantly). Yet, some members have more than 2 teams and also many have only one team.
I can collect data in 2 steps:
1. When user logs in I get their login information and only then I know he/she exists.
2. As bosses can see their team and their team-team-...-team members salaries and pays I only collect information who is your boss (parent) from each user (authorizing that boss to see your salary and pays). The users don't sometimes know who their direct boss is :) and they see other users in alphabetical order so no sorting by position (at this point).
So giving all that I get random updates to one table with ties between user and one of the users boss. It can but doesn't always (mostly) have to be direct boss of the user.
I can get pretty late updates to very high position in the hierarchy in frequent bases.
It is OK to update TREE periodically not on the fly every time I have collected piece of information regarding bosses.
I have given this a thought for 3 days and nights in the row and cannot figure out ideal and not very expensive (for DB) result yet. I'm sure you have good solution for that problem.
At this point I have MySQL but I'm willing to change.
Related
I'm creating a database that will be used to keep track of maintenance performed on equipment in a nursing home. I'm using MS Access 2010, and I'd say my skills are somewhere between novice and intermediate, almost entirely self-taught for this project.
The database structure is as follows:
tblAssetTypes:
TypeID (PK),
MaintenanceSchedule,
EquipmentType,
EquipmentSubgroup,
MaintenanceTime,
TasksRequired
tblUniqueAssets:
UniqueID (PK),
StorageLocation,
TypeID (FK)
tblPrevMaintRecord:
ID (PK),
UniqueID (FK),
DatePerformed,
TimePerformed,
MaintenanceComments
I currently have a form that can be used to record when preventative maintenance is performed on an individual asset. The user enters the UniqueID for that asset, and details about the maintenance (date, time, comments), and then this information is saved to tblPrevMaintRecord. That works fine, but when I presented it to my supervisor he pointed out that in many instances, maintenance people would gather all equipment of a certain type and complete the preventative maintenance in one batch. Needing to enter that data in multiple times would be very tedious and so he asked if it would be possible to record the maintenance performed on multiple items at once. I've spent all day trying to research how to do this but can't seem to find anything that explains how this would be possible.
For each kind of asset, there is one TypeID. However, some values for EquipmentType, such as "Trolley" have subgroups recorded in EquipmentSubgroup (in the example of trolleys, "Medication", "Laundry", "Dressing", "Food", etc.). If there is no subgroup for an EquipmentType, such as "Bed", the EquipmentSubgroup is recorded as a dash "-".
I think ideally, the user should be able to selected any EquipmentType or EquipmentSubgroup category, be shown a list of assets in those categories and the corresponding UniqueIDs, and then select the UniqueIDs that they wish to act on. Then they complete the details of the maintenance (date, time, comments) and records are added for each UniqueID reflecting the maintenance performed on each item. I worry this might be too complicated, and I'm open to compromise solutions.
This is my first time posting here after being a long-term reader, so I hope I've given all the information and detail required for people to be able to help! This database has not been rolled out yet either, so if anyone has other suggestions that they think might be helpful I'm happy to hear them!
I'm a little stumped on whether i can make this process of changing addresses easier. I'll explain the situation:
Basically I have three entities, Students, Addresses, StudentsAddresses. Students have many addresses, since they can change alot and rapidly (especially foster kids / homeless kids). So ill be changing them a lot. However based on each address I Want a user to attach (enter it via the UI) the price it would cost to pick that student up via bus service. So my initial thought was, ok, let me attach a column onto my join table 'StudentsAddresses' called 'dailyPrice', this is the cost for each day a student is picked up, and another column called 'adjustmentPrice', which is an additional cost for whatever special circumstance that requires extra work to pick up a student. Is my thinking going to cause me problems the more students I have in the future? Will it get harder to manage?
Another option I thought about, was creating a new Table called Pricing. And another join-type table called StudentsAddressesPricing
StudentsAddressPricing has three columns,
studentId
addressId
pricingId
each field connects the three together. So if i ever needed Students, with their addresses, and the pricing, i would query this table and eager load Students, Addresses, and Pricing. Does this approach seem much cleaner since i've abstracted pricing out a bit? Trying to determine the best way to go about this without having to many headaches in the future incase I wan't to add more attributes pricing related, or address related.
And then I even thought, hey what if pricing is just different for one day? How would I even consider that. Would I need a different kind of entity to handle that? Is doing alot of joins going to hurt my application performance?
Just looking for some insight on how others would do it, and criticism on why im off the ball.
The main question you should ask yourself is: on what does the price depend?
If the price is determined by the address, you might as well add it to addresses. If the price also depends on the student (e.g., depending on their financial situation), it would make sense to put it into studentsaddresses.
In other words: The table where the price is stored should have foreign keys to everything outside the table that determines the price. If that makes it fit into one of the existing tables, keep it there.
We presently use a pen/paper based roster to manage table games staff at the casino. Each row is an employee, each column is a 20 minute block of time and each cell represents what table the employee is assigned to, or alternatively they've been assigned to a break. The start and end time of shifts for employees vary as do the games/skills they can deal. We need to keep a copy of the rosters for 7 years, with paper this is fairly easy, I'm wanting to develop a digital application and am having difficulty how to store the data in a database for archiving.
I'm fairly new to working with databases, I think I understand how to model the data for a graph database like neo4j, but I had difficulty when it came to working with time. I've tried to learn about RDBMS databases like MySQL, below is how I think the data should be modelled. Please point out if I'm going in the wrong direction or if a different database type would be more appropriate, it would be greatly appreciated!
Basic Data
Here is some basic data to work with before we factor in scheduling/time.
Employee
- ID Number
- Name
- Skills (Blackjack, Baccarat, Roulette, etc)
Table
- ID Number
- Skill/Type (Can only be one skill)
It may be better to store the roster data as a file like JSON instead? Time sensitive data wouldn't be so much of a problem then. The benefit of going digital with a database would be queries, these could help assist time consuming tasks where human error is common.
Possible Queries
Note: Staff that are on shift are either on a break or on the floor (assigned to a table), Skills have a major or minor type based on difficulty to learn.
What staff have been on the floor for 80 minutes or more? (They are due for a break)
What open tables can I assign this employee to based on their skillset?
I need an employee that has Baccarat skill but is not already been assigned to a Baccarat table.
What employee(s) was on this table during this period of time?
Where was this employee at this point in time?
Who is on shift right now?
How many staff on shift can deal Blackjack?
How many staff have 3 major skills?
What staff have had the Baccarat skill for at least 3 months?
These queries could also be sorted by alphabetical order or time, skill etc.
I'm pretty sure I know how to perform these queries with cypher for neo4j provided I model the data right. I'm not as knowledgeable with SQL queries, I've read it can get a bit complicated depending on the query and structure.
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MYSQL Specific
An employee table could contain properties such as their ID number and Name, but am I right that for their skills and shifts these would be separate tables that reference the employee by a unique integer(I think this is called a foreign key?).
Another table could store the gaming Tables, these would have their own ID and reference a skill/gametype with a foreign key.
To record data like the pen/paper roster, each day could have a table with columns starting from 0000 increasing by 20 in value going all the way to 2340? Prior to the time columns I could have one for staff where each employee is represented with their foreign key, the time columns would then have foreign keys to the assigned gaming Tables, the row data is bound to have many cells that aren't populated since the employee shift won't be 24/7. If I'm using foreign keys to reference gaming Tables I now have a problem when the employee is on break? Unless I treat say the first gaming Table entry as a break?
I may need to further complicate things though, management will over time try different gaming Table layouts, some of the gaming Tables can be converted from say Blackjack to Baccarat. this is bound to happen quite a bit over 7 years, would I want to be creating new gaming Table entries or add a column to use a foreign key and refer to a new table that stores the history of game types during periods of time? Employees will also learn to deal new games during their career, very rarely they may also have the skill removed.
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Neo4j Specific
With this data would I have an Employee and a Table node that have "isA" relationship edges mapping to actual employees or tables?
I imagine with the skills for the two types I would be best with a Skill node and establish relationships like so?: Blackjack->isA->Skill, Employee->hasSkill->Blackjack, Table->typeIs->Blackjack?
TIME
I find difficulty when I want this database to now work with a timeline. I've come across the following suggestions for connecting nodes with time:
Unix Epoch seems to be a common recommendation?
Connecting nodes to a year/month/day graph?
Lucene timeline? (I don't know much about this or how to work with it, have seen some mention it)
And some cases with how time and data relate:
Staff have varied days and start/end times from week to week, this could be shift node with properties {shiftStart,shiftEnd,actualStart,actualEnd}, staff may arrive late or get sick during shift. Would this be the right way to link each shift to an employee? Employee(node)->Shifts(groupNode)->Shift(node)
Tables and Staff may have skill data modified, with archived data this could be an issue, I think the solution is to have time property on the relationship to the skill?
We open and close tables throughout the day, each table has open/close times for each day, this could change in a month depending on what management wants, in addition the times are not strict, for various reasons a manager may open or close tables during the shift. The open/closed status of a table node may only be relevant for queries during the shift, which confuses me as I'd want this for queries but for archiving with time it might not make sense?
It's with queries that I have trouble deciding when to use a node or add a property to a node. For an Employee they have a name and ID number, if I wanted to find an employee by their ID number would it be better to have that as a node of it's own? It would be more direct right, instead of going through all employees for that unique ID number.
I've also come across labels just recently, I can understand that those would be useful for typing employee and table nodes rather than grouping them under a node. With the shifts for an employee I think should continue to be grouped with a shifts node, If I were to do cypher queries for employees working shifts through a time period a label might be appropriate, however should it be applied to individual shift nodes or the shifts group node that links back to the employee? I might need to add a property to individual shift nodes or the relationship to the shifts group node? I'm not sure if there should be a shifts group node, I'm assuming that reducing the edges connecting to the employee node would be optimal for queries.
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If there are any great resources I can learn about database development that'd be great, there is so much information and options out there it's difficult to know what to begin with. Thanks for your time :)
Thanks for spending the time to put a quality question together. Your requirements are great and your specifications of your system are very detailed. I was able to translate your specs into a graph data model for Neo4j. See below.
Above you'll see a fairly explanatory graph data model. In case you are unfamiliar with this, I suggest reading Graph Databases: http://graphdatabases.com/ -- This website you can get a free digital PDF copy of the book but in case you want to buy a hard copy you can find it on Amazon.
Let's break down the graph model in the image. At the top you'll see a time indexing structure that is (Year)->(Month)->(Day)->(Hour), which I have abbreviated as Y M D H. The ellipses indicate that the graph is continuing, but for the sake of space on the screen I've only showed a sub-graph.
This time index gives you a way to generate time series or ask certain questions on your data model that are time specific. Very useful.
The bottom portion of the image contains your enterprise data model for your casino. The nodes represent your business objects:
Game
Table
Employee
Skill
What's great about graph databases is that you can look at this image and semantically understand the language of your question by jumping from one node to another by their relationships.
Here is a Cypher query you can use to ask your questions about the data model. You can just tweak it slightly to match your questions.
MATCH (employee:Employee)-[:HAS_SKILL]->(skill:Skill),
(employee)<-[:DEALS]-(game:Game)-[:LOCATION]->(table:Table),
(game)-[:BEGINS]->(hour:H)<-[*]-(day:D)<-[*]-(month:M)<-[*]-(year:Y)
WHERE skill.type = "Blackjack" AND
day.day = 17 AND
month.month = 1 AND
year.year = 2014
RETURN employee, skill, game, table
The above query finds the sub-graph for all employees who have the skill Blackjack and their table and location on a specific date (1/17/14).
To do this in SQL would be very difficult. The next thing you need to think about is importing your data into a Neo4j database. If you're curious on how to do that please look at other questions here on SO and if you need more help, feel free to post another question or reach out to me on Twitter #kennybastani.
Cheers,
Kenny
I am planning on creating a database to track user's time in/time out M-F. Every week should begin on monday and run through sunday.
I have a table filled with my entire user population, so I know which users I need to create entries for and where they belong to. I have proposed so far, a table consisting of the following fields to track the entries (along with example data to fill the fields):
Field Name in table (Example of possible data)
---------------------
Employee (John Smith) 'String
Unit (Quality Assurance) 'String
WeekOf (9/9/13) 'date
InMonday (6:30) 'string, validate either a time in/out or N/A if holiday/vacation
OutMonday (3:15) '^^
HoursWorkedMonday (8.00) 'total hours worked
VacationMonday (0.00) 'if N/A for time, should have hours here
OvertimeMonday (0.00) 'any additional work hours should go here
For this instance, I would have to create In/Out for each day of the week (and perhaps track the date that each day is for). Is this extraneous or is there a seemingly better organization to tracking weekly time measurements? Should I use one table with a unit indicator or multiple tables for each unit?
Usually it's one table with a Date field, an In field and an Out field. That's pretty much standard timesheet data. Take a look at how this guy has it set up.
Make sure you're using an Employee ID in the timesheet, and then you would have a corresponding Employee table with all relevant info (ID, Name, Address, whatever else you store on him/her).
While this project is technically feasible, I have to question the value of making it yourself in Access.
The main issue is with security:
As a desktop program, this can be very easy to hack without precautions. Keep in mind that with Access, the user interface and the designer interface are by default the same thing.
If this is going to be a simple, straightforward db, a motivated user just needs to open the navigation panel and they can add/edit/delete all the timesheets.
If you hide the navigation panel, the user can just do a quick google search and learn to hit F11 (or find it by accident, either way)
You can try regularly (daily? hourly?) transferring the data from the publicly accessible back-end to an archive db that is not accessible to the general users. This can work, but still gives them a window to edit records. And if you don't do the transfer right, they can still add old records.
As a webform on a SharePoint, this can be fairly secure. I'd recommend this if you have Sharepoint.
You should also consider your development time. This is a very common business task across many industries, from restaurants to factories to schools. As such, there's a huge number of cheap web-based options already out there that you can start using today. I'll even assume some of these include summary reviews breaking out numbers by departments as well.
I've never researched these myself, but a quick google search found this interesting page: http://en.wikipedia.org/wiki/Comparison_of_time_tracking_software
So I have this application that I'm drawing up and I start to think about my users. Well, My initial thought was to create a table for each group type. I've been thinking this over though and I'm not sure that this is the best way.
Example:
// Users
Users [id, name, email, age, etc]
// User Groups
Player [id, years playing, etc]
Ref [id, certified, etc]
Manufacturer Rep [id, years employed, etc]
So everyone would be making an account, but each user would have a different group. They can also be in multiple different groups. Each group has it's own list of different columns. So what is the best way to do this? Lets say I have 5 groups. Do I need 8 tables + a relational table connecting each one to the user table?
I just want to be sure that this is the best way to organize it before I build it.
Edit:
A player would have columns regarding the gear that they use to play, the teams they've played with, events they've gone to.
A ref would have info regarding the certifications they have and the events they've reffed.
Manufacturer reps would have info regarding their position within the company they rep.
A parent would have information regarding how long they've been involved with the sport, perhaps relations with the users they are parent of.
Just as an example.
Edit 2:
**Player Table
id
user id
started date
stopped date
rank
**Ref Table
id
user id
started date
stopped date
is certified
certified by
verified
**Photographer / Videographer / News Reporter Table
id
user id
started date
stopped date
worked under name
website / channel link
about
verified
**Tournament / Big Game Rep Table
id
user id
started date
stopped date
position
tourney id
verified
**Store / Field / Manufacturer Rep Table
id
user id
started date
stopped date
position
store / field / man. id
verified
This is what I planned out so far. I'm still new to this so I could be doing it completely wrong. And it's only five groups. It was more until I condensed it some.
Although I find it weird having so many entities which are different from each other, but I will ignore this and get to the question.
It depends on the group criteria you need, in the case you described where each group has its own columns and information I guess your design is a good one, especially if you need the information in a readable form in the database. If you need all groups in a single table you will have to save the group relevant information in a kind of object, either a blob, XML string or any other form, but then you will lose the ability to filter on these criteria using the database.
In a relational Database I would do it using the design you described.
The design of your tables greatly depends on the requirements of your software.
E.g. your description of users led me in a wrong direction, I was at first thinking about a "normal" user of a software. Basically name, login-information and stuff like that. This I would never split over different tables as it really makes tasks like login, session handling, ... really complicated.
Another point which surprised me, was that you want to store the equipment in columns of those user's tables. Usually the relationship between a person and his equipment is not 1 to 1 and in most cases the amount of different equipment varies. Thus you usually have a relationship between users and their equipment (1:n). Thus you would design an equipment table and there refer to the owner's user id.
But after you have an idea of which data you have in your application and which relationships exist between your data, the design of the tables and so on is rather straitforward.
The good news is, that your data model and database design will develop over time. Try to start with a basic model, covering the majority of your use cases. Then slowly add more use cases / aspects.
As long as you are in the stage of planning and early implementation phasis, it is rather easy to change your database design.