As a way to score points for the study I’m doing, as well as out of interest into databases and wanting to help my team I’m trying to build a capacity planning tool in MS Access 2007. I work in a department that handles registering and supporting tenders. I have attached two pictures of what I’m trying to do here.
I’ve already spent some weeks making multiple iterations with colleagues who are involved and help write VBA and SQL (out of interest, wanting to learn something or otherwise. Our core business, however, isn’t developing). The primary goal of the database is as follows:
A user can access, create and modify “cases” that correlates to a case ID that we use in a different system.
A user can write down his capacity per week per year for a case.
multiple users can assign themselves to a case.
Users can leave messages (records) for other users to see on a case
Metadata can be attached to the case
The main problem we seem to be running into is that whenever a user tries through to edit an existing case through the overview, the case data no longer “complies” with entries elsewhere. Forcing updates through visual basic also seems to not have worked so far.
Adding to the complexity: most of the names we use are in dutch.
Here is an overview of the relations.
http://imgur.com/O022LAG
Here is a screenshot of the case overview as seen by a user.
http://imgur.com/kuENqaq
Main question:
How can I make entire records change for multiple users based on the input of one user.
In compliance with the guidelines regarding asking subjective questions I’m trying to be a bit more precise here:
Additionally I’m uncertain:
whether it is our approach that is wrong,
if perhaps we’re overlooking a glaring issue, or
if we should redesign this from scratch with a different layout.
Any help specifying where we should look or what would be advisable to do would be much appreciated!
Kind regards,
Timo
After my first try to misappropriate Ms-Access - with your help - turned out to be a great success, I have been sent back to do "more of this".
A bit of introduction you can skip if you want:
I am building a data foundation about certain projects from which I want to create analysises and overviews.
The data and findings are to be represented in programs like Excel or Powerpoint, so the process itself is very open. It will probably be very visual with detailed points on request.
However, the data might be changing periodically and if this turns out well, I might repeat the process.
Therefore I think the ideal way would be to have a data layer, then a fixed set of queries on that data and then I would (semi-)manually compile the results into a report in whatever format fits, maybe using external data analysis tools such as R in between.
Trouble is, the only database I have access to is.. well.. Ms Access 2010. I am not at liberty to install anything on this machine.
I could of course use non-install or online tools if you have recommendations for this.
tl;dr: I want to use Ms Access to query data from a relational db into tabular format to be processed further by hand, using as little of Ms-Access VBA and forms as possible.
I have since started to implement a prototype in ms-Access, a standard relational database.
One interesting problem I have come up with with this kind of design is that I have a table for companies involved in the projects. Along with this, I have a table of "relationship" - like stakeholding, ownerships or cooperations.
So let's say company A is building project A, but is just a subsidary of company B, which then partly owned by company C and so on.
Now let's say I want to query all companies involved in a project, but as owners I just want to show the last "elements" of the chain.
Imagine I want to sort the list by net assets, which is usually a figure which is only available for the public companies at the end of the chain, not the project subsidaries up the chain etc.
Is this possible with (Ms-)SQL or would I need to do this in VBA?
Right now I think I could manage do write a VBA function and dump it into a temporary table, but then I'd have to create forms and such.
Another idea that immediately springs from this is ´to answer the question "In which project does company C have stake" by a query. You can see where this is going.
I would prefer the database and the queries to be as flexible as possible (and in this case, independend from the actual Access).
So this time, no mock-program or user-interface. It was a pain to get what I want from Access in the last project and that was with a very specific question set...
But in general I am also open to use different tools if I can.
Thank you so much!
Modelling hierarchies in an RDBMS is a fairly tricky process - some (like Oracle) have built-in functionality to query hierarchical data, but I don't think Access does.
The best solution is to use a "nested set" model. This allows you to model hierarchical data while using standard SQL; it's also pretty fast for querying.
If your data isn't hierarchical, the nested set isn't so useful; the typical solution in that case is to introduce a table to map the relationship - typically including the two related entities, and often with a "relationship type" field (e.g. "parent", "part owner" etc.). This is often called a Directed Acyclical Graph or DAG. There are several ways of modelling these in a database; a "Closure table" is probably the most efficient. This article shows how to do this - it's a heavy read, but I think it answers your question.
Is there a quick and easy way to make a VB.NET user interface for managing the data in a normalized DataSet?
I know that is a very subjective question, so let me explain. For a brief period early in my career, I used to create user interfaces in Microsoft Access. I developed a simple, but very effective approach to user interface design. Here are some details of that approach:
Create one form per table. Put on
each form all controls necessary to
completely manage one row in the
table.
Use combo boxes for
foreign-key columns.
Give the user a
standard way to add rows and delete
rows.
Use Apply and Undo buttons.
Let
the user navigate from one row to
another with a list box.
Provide a
search box and filter options for
more efficient navigation.
Let the
user double-click on controls
representing foreign-key columns to
quickly navigate from one form to
another.
Make the state of each form
persistent (so the user always
returns to the last navigation point)
etc.
Simple, right? I found that Access encouraged this approach. It has many built-in features that make this kind of UI easy. For instance, creating a combo box to represent a foreign key relationship takes about 10 seconds.
Well, I haven't worked in Access for a while. A couple of years ago, however, I was hired to write an application in VB.NET on the NET 2.0 framework. To get a data management user interface up and running quickly, I used my Access experience to write a quick & easy prototype in Access -- that took me about one week. Then I hired a programmer to implement that same UI in VB.NET. What a nightmare! We've been working on that implementation for a year, and I'm still very unsatisfied with the results. Some of the problems we are having:
Apply and Undo buttons don't work quite right. We can't find an event that tells us when the form is "dirty" (thus making Apply and Undo relevant).
Navigation from row to row and from form to form requires surprisingly complicated code. I get the impression that we are fighting against NET's binding features, not working with them the way they were intended to be used.
The NET controls seem buggy. For instance, when the user types a value into a combo box (as opposed to choosing it from the drop down), it doesn't trigger the SelectedValueChanged event.
We seem to be repeating a lot of information. For instance, the DataSet knows there is a relationship between the columns in two tables, but we must nevertheless effectively repeat the details of that relationship when we program the combo boxes, binding, navigtation features, etc.
We still don't have good solutions for the filter and search features. There are lots of little details to work out. (For instance, what if you choose a filter that doesn't include the currently displayed row?)
We are writing many helper functions and classes to simplify the work, and I can't figure out why that effort hasn't already been done by others -- I'm certain we are reinventing the wheel.
etc.
By themselves, none of the above are a big deal -- there are effective solutions to each one. Taken together, however, these problems are making my UI development go much slower than expected.
In an ideal world, I should be able to create a small amount of code relevant to my specific data model (for instance, one user control per table establishing the layout and logic relevant to the rows in that table) then integrate that code into a template which interprets the data model and handles everything else -- navigation, adding and deleting, apply and undo, search and filter, etc.
Thus, my question: Is there anything out there which makes this type of UI development easier?
I've searched the web for various combinations of "generic forms", "UI templates", "data managment forms", etc., but I haven't found anything on topic. Perhaps I just don't know the buzzwords. Is there a specific name for this type of UI development task?
Create UCs for each table. Drop a grid control onto the UC and bind it to the tables dataset using VS's wizard. Select the options that allow for insert, update, delete. Each row on the grid will have those buttons/actions automatically added for you.
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(Note: I realize this is close to How do you document your database structure? , but I don't think it's identical.)
I've started work at a place with a database with literally hundreds of tables and views, all with cryptic names with very few vowels, and no documentation. They also don't allow gratuitous changes to the database schema, nor can I touch any database except the test one on my own machine (which gets blown away and recreated regularly), so I can't add comments that would help anybody.
I tried using "Toad" to create an ER diagram, but after leaving it running for 48 hours straight it still hadn't produced anything visible and I needed my computer back. I was talking to some other recent hires and we all suggested that whenever we've puzzled out what a particular table or what some of its columns means, we should update it in the developers wiki.
So what's a good way to do this? Just list tables/views and their columns and fill them in as we go? The basic tools I've got to hand are Toad, Oracle's "SQL Developer", MS Office, and Visio.
In my experience, ER (or UML) diagrams aren't the most useful artifact - with a large number of tables, diagrams (especially reverse engineered ones) are often a big convoluted mess that nobody learns anything from.
For my money, some good human-readable documentation (perhaps supplemented with diagrams of smaller portions of the system) will give you the most mileage. This will include, for each table:
Descriptions of what the table means and how it's functionally used (in the UI, etc.)
Descriptions of what each attribute means, if it isn't obvious
Explanations of the relationships (foreign keys) from this table to others, and vice-versa
Explanations of additional constraints and / or triggers
Additional explanation of major views & procs that touch the table, if they're not well documented already
With all of the above, don't document for the sake of documenting - documentation that restates the obvious just gets in people's way. Instead, focus on the stuff that confused you at first, and spend a few minutes writing really clear, concise explanations. That'll help you think it through, and it'll massively help other developers who run into these tables for the first time.
As others have mentioned, there are a wide variety of tools to help you manage this, like Enterprise Architect, Red Gate SQL Doc, and the built-in tools from various vendors. But while tool support is helpful (and even critical, in bigger databases), doing the hard work of understanding and explaining the conceptual model of the database is the real win. From that perspective, you can even do it in a text file (though doing it in Wiki form would allow several people to collaborate on adding to that documentation incrementally - so, every time someone figures out something, they can add it to the growing body of documentation instantly).
One thing to consider is the COMMENT facility built into the DBMS. If you put comments on all of the tables and all of the columns in the DBMS itself, then your documentation will be inside the database system.
Using the COMMENT facility does not make any changes to the schema itself, it only adds data to the USER_TAB_COMMENTS catalog table.
In our team we came to useful approach to documenting legacy large Oracle and SQL Server databases. We use Dataedo for documenting database schema elements (data dictionary) and creating ERD diagrams. Dataedo comes with documentation repository so all your team can work on documenting and reading recent documentation online. And you don’t need to interfere with database (Oracle comments or SQL Server MS_Description).
First you import schema (all tables, views, stored procedures and functions – with triggers, foreign keys etc.). Then you define logical domains/modules and group all objects (drag & drop) into them to be able to analyze and work on smaller chunks of database. For each module you create an ERD diagram and write top level description. Then, as you discover meaning of tables and views write a short description for each. Do the same for each column. Dataedo enables you to add meaningful title for each object and column – it’s useful if object names are vague or invalid. Pro version enables you to describe foreign keys, unique keys/constraints and triggers – which is useful but not essential to understand a database.
You can access documentation through UI or you can export it to PDF or interactive HTML (the latter is available only in Pro version).
Described here is a continuous process rather than one time job. If your database changes (eg. new columns, views) you should sync your documentation on regular basis (couple clicks with Dataedo).
See sample documentation:
http://dataedo.com/download/Dataedo%20repository.pdf
Some guidelines on documentation process:
Diagrams:
Keep your diagrams small and readable – just include important tables, relations and columns – only the one that have any meaning to understand big picture – primary/business keys, important attributes and relations,
Use different color for key tables in a diagram,
You can have more than one diagram per module,
You can add diagram to description of most important tables/with most relations.
Descriptions:
Don’t document the obvious – don’t write description “Document date” for document.date column. If there’s nothing meaningful to add just leave it blank,
If objects stored in tables have types or statuses it’s good to list them in general description of a table,
Define format that is expected, eg. “mm/dd/yy” for a date that is stored in text field,
List all known/important values an it’s meaning, e.g. for status column could be something like this: “Document status: A – Active, C – Cancelled, D – Deleted”,
If there’s any API to a table – a view that should be used to read data and function/procedures to insert/update data – list it in the description of table,
Describe where does rows/columns’ values come from (procedure, form, interface etc.) ,
Use “[deprecated]” mark (or similar) for columns that should not be used (title column is useful for this, explain which field should be used instead in description field).
We use Enterprise Architect for our DB definitions. We include stored procedures, triggers, and all table definitions defined in UML. The three brilliant features of the program are:
Import UML Diagrams from an ODBC Connection.
Generate SQL Scripts (DDL) for the entire DB at once
Generate Custom Templated Documentation of your DB.
You can edit your class / table definitions within the UML tool, and generate a fully descriptive with pictures included document. The autogenerated document can be in multiple formats including MSWord. We have just less than 100 tables in our schema, and it's quite managable.
I've never been more impressed with any other tool in my 10+ years as a developer. EA supports Oracle, MySQL, SQL Server (multiple versions), PostGreSQL, Interbase, DB2, and Access in one fell swoop. Any time I've had problems, their forums have answered my problems promptly. Highly recommended!!
When DB changes come in, we make then in EA, generate the SQL, and check it into our version control (svn). We use Hudson for building, and it auto-builds the database from scripts when it sees you've modified the checked-in sql.
(Mostly stolen from another answer of mine)
This answer extends Kieveli's above, which I upvoted. If your version of EA supports Object Role Modeling (conceptual design, vs. logical design = ERD), reverse engineer to that and then fill out the model with the expressive richness it gives you.
The cheap and lighter-weight option is to download Visiomodeler for free from MS, and do the same with that.
The ORM (call it ORMDB) is the only tool I've ever found that supports and encourages database design conversations with non-IS stakeholders about BL objects and relationships.
Reality check - on the way to generating your DDL, it passes through a full-stop ERD phase where you can satisfy your questions about whether it does anything screwy. It doesn't. It will probably show you weaknesses in the ERD you designed yourself.
ORMDB is a classic case of the principle that the more conceptual the tool, the smaller the market. Girls just want to have fun, and programmers just want to code.
A wiki solution supports hyperlinks and collaborative editing, but a wiki is only as good as the people who keep it organized and up to date. You need someone to take ownership of the document project, regardless of what tool you use. That person may involve other knowledgeable people to fill in the details, but one person should be responsible for organizing the information.
If you can't use a tool to generate an ERD by reverse engineering, you'll have to design one by hand using TOAD or VISIO.
Any ERD with hundreds of objects is probably useless as a guide for developers, because it'll be unreadable with so many boxes and lines. In a database with so many objects, it's likely that there are "sub-systems" of a few dozen tables and views each. So you should make custom diagrams of these sub-systems, instead of expecting a tool to do it for you.
You can also design a pseudo-ERD, where groups of tables are represented by a single object in one diagram, and that group is expanded in another diagram.
A single ERD or set of ERD's are not sufficient to document a system of this complexity, any more than a class diagram would be adequate to document an OO system. You'll have to write a document, using the ERD's as illustrations. You need text descriptions of the meaning and use of each table, each column, and the relationships between tables (especially where such relationships are implicit instead of represented by referential integrity constraints).
All of this is a lot of work, but it will be worth it. If there's a clear and up-to-date place where the schema is documented, the whole team will benefit from it.
Since you have the luxury of working with fellow developers that are in the same boat, I would suggest asking them what they feel would convey the needed information, most easily. My company has over 100 tables, and my boss gave me an ERD for a specific set tables that all connect. So also, you might want to try breaking 1 massive ERD into a bunch of smaller, manageable, ERDs.
Well, a picture tells a thousand words so I would recommend creating ER diagrams where you can view the relationship between tables at a glance, something that is hard to do with a text-only description.
You don't have to do the whole database in one diagram, break it up into sections. We use Visual Paradigm at work but EA is a good alternative as is ERWIN, and no doubt there are lots of others that are just as good.
If you have the patience, then using html to document the tables and columns makes your documentation easier to access.
If describing your databases to your end users is your primary goal Ooluk Data Dictionary Manager can prove useful. It is a web-based multi-user software that allows you to attach descriptions to tables and columns and allows full text searches on those descriptions. It also allows you to logically group tables using labels and browse tables using those labels. Tables as well as columns can be tagged to find similar data items across your database/databases.
The software allows you to import metadata information such as table name, column name, column data type, foreign keys into its internal repository using an API. Support for JDBC data sources comes built-in and can be extended further as the API source is distributed under ASL 2.0. It is coded to read the COMMENTS/REMARKS from many RDBMSs.You can always manually override the imported information. The information you can store about tables and columns can be extended using custom fields.
The Data Dictionary Manager uses the "data object" and "attribute" terminology instead of table and column because it isn't designed specifically for relational databases.
Notes
If describing technical aspects of your database such as triggers,
indexes, statistics is important this software isn't the best option.
It is however possible to combine a technical solution with this
software using hyperlink custom fields.
The software doesn't produce an ERD
Disclosure: I work at the company that develops this product.
How would you create a database in Microsoft Access that is searchable only by certain fields and controlled by only a few (necessary) text boxes and check boxes on a form so it is easy to use - no difficult queries?
Example:
You have several text boxes and several corresponding check boxes on a form, and when the check box next to the text box is checked, the text box is enabled and you can then search by what is entered into said text box
(Actually I already know this, just playing stackoverflow jeopardy, where I ask a question I know the answer just to increase the world's coding knowledge! answer coming in about 5 mins)
My own solution is to add a "filter" control in the header part of the form for each of the columns I want to be able to filter on (usually all ...). Each time such a "filter" control is updated, a procedure will run to update the active filter of the form, using the "BuildCriteria" function available in Access VBA.
Thus, When I type "*cable*" in the "filter" at the top of the Purchase Order Description column, the "WHERE PODescription IS LIKE "*cable*" is automatically added to the MyForm.filter property ....
Some would object that filtering record source made of multiple underlying tables can become very tricky. That's right. So the best solution is according to me to always (I mean it!) use a flat table or a view ("SELECT" query in Access) as a record source for a form. This will make your life a lot easier!
Once you're convinced of this, you can even think of a small module that will automate the addition of "filter" controls and related procedures to your forms. You'll be on the right way for a real user-friendly client interface.
This is actually a pretty large topic, and fraught with all kinds of potential problems. Most intermediate to advanced books on Access will have some kind of section discussing "Query by Form," where you have an unbound form that allows the user to choose certain criteria, and that when executed, writes on-the-fly SQL to return the matching data.
In anything but a flat, single-table data structure, this is not a trivial task because the FROM clause of the SQL is dependent on the tables queried in the WHERE clause.
A few examples of some QBF forms from apps I've created for clients:
Querying 4 underlying tables
Querying a flat single table
Querying 3 underlying tables
Querying 6 underlying tables
Querying 2 underlying tables
The first one is driven by a class module that has properties that reflect the criteria selected in this form, and that has methods that write the FROM and WHERE clauses. This makes it extremely easy to add other fields (as long as those fields don't come from tables other than the ones already included).
The most complex part of the process is writing the FROM clause, as you have to have appropriate join types and include only the tables that are either in the SELECT clause or the WHERE clause. If you include anything else, you'll slow down your query a lot (especially if you have any outer joins).
But this is a big subject, and there is no magic bullet solution -- instead, something like this has to be created for each particular application. It's also important that you test it thoroughly with users, since what is completely clear and understandable to you, the developer, is often pretty darned mystifying to end users.
But that's a principle that doesn't just apply to QBF!
At start-up, you need to show a form and disable other menus etc. That way your user only ever sees your limited functionality and cannot directly open the tables etc.
This book excerpt, Real World Microsoft Access Database Protection and Security, should be enlightening.
For a question that vague, all that I can answer is open MS Access, and click the mouse a few times.
On second thought:
Use the "WhereCondition" argument of the "OpenForm" method
If the functionality is very limited and/or specialised then a SQL database is probably going to be overkill anyhow e.g. cache all combinations of the data locally, in memory even, and show one according to the checkboxes on the form. Previously you could have revoked permissions from the table and granted them only on VIEWs/PROCs that queried the data in the prescribed way, however security has been removed from MS Access 2007 so you can you now really stop users bypassing your simple app using, say, Excel and querying the data any way they like ...but then isn't that the point of an enterprise database? ;-)