I am developing a simple database for a competition by Microsoft Access 2010. There are one issue that I am facing right now and I need your help.
In my table Schools, I have a list of school that participate in the competition, with the year they participate (the competition is organized every year and 1 school can participate in many years). I also have another table called Team, which contain teams that come from different schools, and I create a Data Entry Form for this entity. And to make it easy to type in, I create a combobox for school list, so that when people type in team information, they can easily choose their school name from the list.
However, because 1 school can participate in many years, then there are duplicates in my combobox. Could you please help me how to remove the duplicates?
I tried SELECT DISTINCT but it did not work.
Any recommend? Thks in advance.
I don't know if I have enough information to give you the help you want, but if I am understanding you correctly you may want to use GROUP BY in your query for the combo box.
Something like this (I don't what your field name is so I used "SchoolName")
SELECT Schools.SchoolName
FROM Schools
GROUP BY Schools.SchoolName;
Hopefully this helps
Related
I'm an intern student at a company that does both wiring and aircon services. The job that they gave me was to make a database for them. I don't have any experience in anything related to databases.
So, I started to look up videos and stuff to at least learn a bit about databases and made something that works and I made it after 1.5 months of learning.
in the database that I created,
I have 1 table (CustomerDetailsT):
CustomerID (pk)
CustomerName
PhoneNumber
Address
Aircond (type and model of ac,ex: WM daikin 1.0HP)
AcDetails (what has been done for the ac.)
Others (yes/no) (Wiring, installing a fan and so on)
WhatHasBeenDone (shows what has been done for others)
Then 3 queries (CustomerOthersDetailsQ, CustomerAcDetailsQ, CustomerDetailsQ).CustomerAcDetailsQ has CustomerName, PhoneNumber, Address, Aircond and AcDetails. CustomerOthersDetailsQ has CustomerName, PhoneNumber, Address, Others, and WhatHasBeenDone.CustomerDetailsQ has CustomerID, CustomerName, PhoneNumber and Address
And 1 form with 3 subforms.
it's a search form, which would search for customers as we're typing in their name/phone number and it will show what has been done for the customer.
With this, I have created what the company wants, but now they want to add dates. Dates which would show when we have done something for a customer. Dates for Aircond and the Others stuff.
I've tried with what I know and it didn't work. tried searching it on youtube and google, but still couldn't find it.
how can I go about doing this?. I have tried having separate tables for each service, but it became a hassle when I wanted to create a new customer. . I hope I could some help, I could send pictures if someone needs them.
[1]: https://i.stack.imgur.com/mtrmC.png [The Customer search form] [1]: https://i.stack.imgur.com/A3Y9d.png [example of a customer that has ac installation] [1]: https://i.stack.imgur.com/dsGL5.png [example of a customer that has both ac and wiring done]
Acknowledging the question is too broad, here is some guidance. One of the nice things about Access is that each database is a single file. First protect your work by finding that file and make two copies. Make a backup and a play around version. Only mess with the play around version.
Your question indicates you are still learning Table Normalization and 1 to many relationships. Both of these topics are general to all databases, so you don't have to restrict yourself to just Access when looking for guides and Youtube videos.
Part of normalization is putting separate entities into their own tables. Also, in Access there is a big payoff for using the Relationship Tool, so here is a rather lame example of normalization:
Make sure to select the checkboxes when setting up relationships.
WhatHasbeenDone should also have WhatHasbeenDoneDate. I've wrapped AC and Other as Unit because later it will be easier than having two WhatHasBeenDone tables(AC)(Other).
Now imagine someone taking the customer request call. They just want to see a form to enter the customer details, request, unit-type, etc. They don't want to see those tables. Even with training entering data in the tables is error prone. The person fulfilling the request just wants to enter what they did and when. That's how you start to figure out what your final Data entry forms will look like.
Since we normalized the tables and used the relationships tool, the payoff is Access can give us an assortment of working starter forms. Select Each Table and then hit Create and then hit Form. Choose your Favorites and start playing around from there. While playing, keep in mind that Access will not let you add an item on the many side of a relationship unless there is an item on the 1 side.
For example I selected the customers table and hit create form:
Access uses a concept of form and subform based on separate but related tables. So, to get a form that shows what has been done for each customer I created a form for the What has been done table, and dragged it onto the customers form:
Unless an ID is also being used as a part number or something there is probably no reason for the person entering data to see it. So I removed the texboxes bound to ID's. Except for UnitTypeID, where I replaced the textbox with a combobox that displays the userfriendly UnitDescription. The ID's are still part of the form recordsources, Access is still adding new IDs and using those IDs to put the appropriate data in the right tables.
Oh, didn't we need dates (went back and added a date to the table, and adjusted the subform accordingly). Also changed the subform format from single record to continuous records to show multiple dates:
In conclusion and in my opinion your final forms will use VBA behind the scenes to insert data from the forms into the tables. This is because either you will want to rapidly insert multiple records or How the end users think about the data will not match the default forms and subforms approach Access depends upon to figure out how to insert the data. However, the default approach is fast and I always use it for version 1 of my Access Databases.
P.S. For simplicity I avoided including any Many to Many relationships
I have a hasMany through schema for volunteers who make up teams. It's like this:
Volunteers belong to many Teams
Teams belong to many Volunteers
Both through a table of Memberships.
The reason why I used a through table is because I need to select certain volunteers as team leaders in certain teams they participate in. The field is boolean --TINYINT(1)-- and part of my join table. This is similar to CakePHP documentation's example of starred, I assume, on which an element is selected as highlighted.
Now, I am wondering on how to select volunteers as team leaders on an form in a way that I can load the list of associated volunteers (or during the selection page) and then mark a checkbox for 'team leader' for each name, or a widget that allows me to select only from the reduced list of volunteers already members of this team. So far, I have decided to leave the associated volunteer selection in the team edit page:
<?php echo $this->Form->control('volunteers._ids'); ?>
Which is pretty easy and straightforward, but from here, But I can't seem to find a way to generate the selection box for the already-reduced list of volunteers. I've found everywhere for an example of this, but I probably don't have the skill level to make a good search, as I'm not sure how to word my question, I guess.
Can you please help me out? I understand that a through table has a belongTo relation, but I don't know whether CakePHP generates the list of inputs for me, or whether I need to create a loop (which would mean that I need to add something on the controller to do so).
Thank you!
I'm creating an Access DB tool to centralize some administration work for two teams. I work for a company that creates examens.
In my database I have several tables. But the two relevant tables are one where I list all the exams and one where I list all the subjects.
Table exams
Table subjects (relevant columns in this story: subject and type)
In the table of subjects there are three colums. One for ID, one for the subject itself and one for the kind of subject. (Oral exam, written exam...)
Example data
1 - Oral English - Oral
2 - Written French - Written
3 - Computer Science - Pratical
4 - History - Written
So, in the table of exams, I was able to link it succesfully with the table of subjects. But I'm able to create mismatches.
So, I can say that oral english is a written exam.
Is there a way to prevent this? So, that Access gives an error when I put something in the exam table that doesn't match the subject table? Or can I somehow autofill the type column when I enter the subject in the exam table?
I hope I explained the issue clearly enough, if there are any questions, feel free to ask me. I'm using Access 2013 in this project
After reading the question 3 times, I figured what you wanted is to autofill a control (i.e. textbox) based on the pick of a combobox.
To make it so, your combo's property limit to list should be set to yes.
To make it impossible for users to type wrong types of exam, like selecting English and writing Practice Exam, the textbox containing ExamType, locked's property must be set to true.
Then on the Combobox (Dropdown) Afterupdate event, you must insert the code below to search automagically for the Type of exam:
textboxExamType.value = Dlookup("[KindofSubject]","TableSubjects","[Subject]='" & comboboxExam.Text & "'")
You will have to adjust the names of the controls and fields, because you did not provide them. Next time first read How to Ask
I'm fairly new at access and I have no clue how to handle this situation. I dont even know where to start so any help would be greatly appreciated.
So I have to design this data base that has items such as "audio board X.xx" When a customer orders lets say "audio board 2.4", the database will know that the board requires 2x4K Resisters and 4x2uf Capacitors and 2X4401 BJTs. And it would automatically pull them from the inventory when processing this order so later on I can just look at the inventory list lets say at the end of the week and will know what parts i would need to order to restock.
now, i looked for help online, the only thing i could find similar was something called "Bill of Materials" AKA "BOM" sheets or something... but none of them told me how to make one or anything like that.
I'm really new at this, and am a total noob. I'm using Access 2010. Any Help would be appreciated.
First, read http://r937.com/relational.html
You will need a design on the lines of:
Parts
ID -->Primary key
Description
Etc
Components
ID -->Primary key
Description
Etc
PartsComponents --> Junction table
PartID ---) ??
ComponentID ---)
If a part can have only one of each component, life is simple enough and PartID + ComponentID is your primary key, if a part can only have a set number of a particular component, it may be possible to treat the set as a single item, if the part can have a variable number of a component, things get a little more complicated. A quantity field in the junction table would probably work, though.
You then have a fairly standard set of tables for customers and orders, including an order detail table, which gets updated by an append query from the junction table information when a customer selects a part.
I'm creating a database with Access. This is just a test database, similar to my requirements, so I can get my skills up before creating one for work. I've created a database for a fictional school as this is a good playground and rich data (many students have many subjects have many teachers, etc).
Question 1
What is the difference, if any, between using a Lookup column and a many-to-many associate table?
Example: I have Tables 'Teacher' and 'Subject'. Many teachers have many subjects. I can, and have, created a table 'Teacher_Subject' and run queries with this.
I have then created a lookup column in teachers table with data from subjects. The lookup column seems to take the place of the teacher_subject table. (though the data on relationships is obviously duplicated between lookup table and teacher_subject and may vary). Which one is the 'better' option? Is there a snag with using lookup tables?
(I realize that this is a very 'general' question. Links to other resources and answers saying 'that depends...' are appreciated)
Question 2
What attracts me to lookup tables is the following: When creating a form for entering subjects for teachers, with lookup I can simply create checkboxes and click a subject for a teacher 'on' or 'off'. Each click on/off creates/removes a record in the lookup column (which replaces teacher_subject).
If I use a form from a query from teacher subject with teacher as main form and subject as subform I run into this problem: In the subform I can either select each subject that teacher has in a bombo box, i.e. click, scroll down, select, go to next row, click, scroll down, etc. (takes too long) OR I can create a list box listing all available subjects in each row but allowing me to select only one. (takes up too much space). Is it possible to have a click on/off list box for teacher_subject, creating/removing a record there with each click?
Note - I know zero SQL or VB. If the correct answer is "you need to know SQL for this" then that's cool. I just need to know.
Thanks!
Lookup columns in tables will cause you more stress than joy. Unless you need them for Sharepoint, they should be avoided. You may wish to read http://r937.com/relational.html and http://www.mvps.org/access/tencommandments.htm
I wouldn't use them. Your example is fine, but there are limitations. What do you do when you need to reference another field from the Subject table other than the name? How would you differentiate subjects that are only offered on a semester basis?
You have no way of getting a count of how many subjects each teacher is assigned without some ugly coding.
Another limitation, is when you start identifying who taught what courses during a given school year.
I'm kind of unclear on your second question, but it sounds to me like you need a subform with a dropdown list.
If you want to do the checkbox thing, it quickly becomes a lot more complicated. To me, you're starting from user interface and working backwards to structure, instead of going the other direction.
I hesitate to mention it, but in terms of full disclosure you should know that in A2007 and A2010, you have multi-value fields available, and they are presented with exactly the UI you describe. But they have many of the same problems as lookup fields, and are quite complex to work with in code. Behind the scenes, they are implemented with a standard many-to-many join table, but it's all hidden from you.
I wish MS would make the listbox with checkbox control that is used with MV fields available for all listboxes, but binding that to a many-to-many join table would be complex if the listbox control were not designed for that (with link child/link master properties, for instance).
I tried to come up with a way to offer you the UI feature you prefer from multi-value fields without actually using multi-value fields. That seems challenging to me.
The closest I could come up with is to load a disconnected recordset with your "List" choices and a check box field. Then create a form, or subform, based on that recordset which you present in datasheet view. It could look similar to a combo bound to a multi-value field. In the after update event of the checkbox field, you would need code to add or remove a record from the junction table as required.
However, I don't know if this is something you would care to tackle. Earlier you indicated a willingness to learn SQL if needed; the approach I'm suggesting would also require VBA. Maybe take a look at Danny Lesandrini's article, Create In-Memory ADO Recordsets, to see whether it is something you could use.
OTOH, maybe the most appropriate answer for you is to keep the multi-value fields and get on with the rest of your life. I'm stuck. But now that we know you are actually using multi-value fields, perhaps someone else will be able to offer you a more appropriate suggestion.