I have a contact database, created on SQL server. An example of its many to many relationships is below:
1- Contact table (ContactID, Fname, Lname, ...)
2-Contact_Skill table (ContactID, SkillID, Score)
3-Skill table (SkillID, Skill_name, Skill_type)
For easier interaction, I linked this databse with MS access file (which will be the interface, used by users). Users mainly use it for insertion, and I have somewhere else a SQL report server to retrieve some data and do some reports.
My issue now is that, I'm trying to find an easier way (without programming) to insert data in the intermediate table (Contact_Skill), other than getting the IDs manually. A thing like a drop down menu, that enables the user to choose the skill and it turns into its ID. Any easier way would be so welcomed as well. Thanks
Ok, you likely don't need code, or at the very least VERY little code, and you certainly don't have to write code to insert the records.
So, I would create the form (bound directly to the linked contact table.
So, you can use ctrl-f, or whatever to search, find, jump to your record you want to edit. (so built in search features will suffice for now).
In that form, you will drop in a sub form. (a continues form - multiple items would work nice here.
So, in that form you have this:
In this example, I have
customers
Invoices
Invoice details
So, really, I have near example the same kind of setup. One master table (customers)
Then a child table of invoices.
And then for each invoice, we have details of the invoice.
So, your main form will have that sub form dropped in that shows the contact skills.
In my case, I have this:
So, for this, you not really written any code.
Now, do note that for each invoice (or your case of contact skills).
Note how I have a edit button in that continues form.
This allows our "drill" down.
The code behind this button is:
if me.Dirty = true, then me.Dirty = False
docmd.OpenForm "frmInvoice",,,"ID = " & me!id
So, clicking on edit will launch a new "main" form based on invoice (or in your case skills) the ONE record.
Now for that skills record, it not clear if you have another drill down (child table), but lets assume you do!
so, In that form, you simply drop in another sub form (again continues items), and you thus are now free to add more skills to that one contact skill.
In my case, it is invoice details, so we have this:
The above screens are rather crude (they are test scenes), but it shows a design in which you dealing with 3 typical related tables.
So the whole system works with about 6 lines of code. Just keep in mind that when you drop in a sub form to relate child items? Access will setup the foreign key value that belongs to the parent table that has the one "main" record, and that sub-form of child records. All that is required is that the link master/child setting is setup correct. Once done, then Access will manage and set the correct values used to relate the tables to each other, and you don't have to write any SQL or even any code for that matter. (you are free to add a sub form record, and then hit Edit button for further details to edit, or as noted add more child records to that form you just launched.
So related tables, and adding of child records is VERY automatic in Access, and you don't write code to add the records - access will do all this work for you if you follow the above design pattern. About the only code you ever had to add is the the "edit" button to launch the next form in the sequence.
Related
I have upgraded from access 2010 adp to 2013 accdb and encountered several challenges. I have a Main Form that has one Sub Form. The Form is coded to allow either new records or bring up all the current records. They are linked by the Primary Key from the Main Form. The sub form is based on a query, but the form won't display if I use the query. The query is updatable. When I switch the recordsource to the table, it displays, but I am not sure it's properly linked. I say that because I have a CBO that won't display any data which is linked to a field on the main form. Works fine is sql, but not in the form. It all worked, of curse, in access 2010.
If Forms!FrmRequest.NewRecord = True Then
reset_unbound
cmdEmail.Enabled = True
Forms!FrmRequest!SfrmReqeust.Visible = True
Once the Main Form information is entered and the PK is created, the Subform has a one to many relationship (table used by main form and table used by subform). My theory is that because the table and query are linked to the backend (SQL Server), the keys aren't getting updated to link the new recordset. If this is the case, how do I programmatically relink the table/query?
did you set the link master and child settings correct?
this one:
So, by setting the above, then the sub form will only show correct related records.
However, in code, if you shove in, and set the data source of the sub form, then sometimes the above two link master and child settings can be lost.
but, as long as the correct so called foreign key value in part of and included in your query? Then you should freely be able to base that sub form on a query, or a directly to a linked table.
And note that ZERO code is required to set the FK value if you use the above, and this includes linked tables to SQL server.
So, access will set, and insert the FK value for you, but you have to tell access what column is to be used for linking up the relationships.
With above, then if you filter or load the main form to ONE record, then the sub form should correctly show only the correct child reocrds.
and if you add a new row to the sub form, it will insert and set the FK value for you automatic without code.
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 been tasked with create a tracker for company work flow.
I have 10 tables with data in them. There are attributes all the tables have in common. I made a table with those attributes, giving those records a unique ID that could join them to the unique attribute records of the original tables. I am also linking a personnel table to the original tables. All of these tables exist on my SQL Server back end. I Have made a query in Access that displays all the information I was given. I'm going to use the forms in access as a front end to display, edit, and add records.
The issue I am encountering is that I can not write to a query that has externally linked tables. I have spent a lot of time normalizing this data and I know I can get around it by making tables with redundant attributes in SQL and not writing to the query, but rather write to the linked tables instead. Just wondering if there is a way around this.
Thanks
In general, even without linked tables, such queries are NOT updatable.
The general approach when working with multiple tables is to use sub forms for the child tables. That way, each form is only bound to one table. (You are free even to bind such forms directly to the linked table).
Thus, you might say have a customer table and then a table of invoices. So your main form will display the one customer and is bound to that one table.
In the sub form, you can then display all of the invoices.
So to combine multiple tables into a form or screen that allows users to update the data, or add more data, you don’t build some query that joins all the data together, but simply combine several forms into one form. But each of those separate forms will display data from the given related child table.
Here is a typical invoice form thus built in Access:
The top part is the “main” form of an invoice. It is bound to the customer table – one record. Then the multiple lines of detail is the invoice details table. So the form does NOT use queries, but each part of the form and sub forms are bound to the given related tables. You are binding each form directly to the linked table (or tables if you need to show related data like above).
This approach allows you to cobble together a set of forms that edit related tables, but each form is bound directly to the linked table.
So the fact of linked tables or not is moot – such queries are not used to edit data and such queries from link or non-linked tables are NOT updatable.
So your form + sub forms will follow the pattern of related tables that you need to work together as one whole view and means to edit data. You don’t need nor want to use a query to fill these forms.
You most certainly will provide some kind of “search” form, or some means to pull up say one customer invoice, and that invoice along with its sub forms will display the related data, and also allow editing of that data.
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.
I have a SQL Server as backend and use ms access as frontend.
I have two tables (persons and managers), manager is derived from persons (a 1:1 relation), thus i created a view managersFull which is basically a:
SELECT *
FROM `managers` `m`
INNER JOIN `persons` `p`
ON `m`.`id` = `p`.`id`
id in persons is autoincrementing and the primary key, id in managers is the primary key and a foreign key, referencing persons.id
now i want to be able to insert a new dataset with a form in ms access, but i can’t get it to work. no error message, no status line, nothing. the new rows aren’t inserted, and i have to press escape to cancel my changes to get back to design view in ms access.
i’m talking about a managers form and i want to be able to enter manager AND person information at the same time in a single form
my question is now: is it possible what i want to do here? if not, is there a “simple” workaround using after insert triggers or some lines of vba code?
thanks in advance
The problem is that your view is across several tables. If you access multiple tables you could update or insert in only one of them.
Please also check the MSDN for more detailed information on restrictions and on proper strategies for view updates
Assuming ODBC, some things to consider:
make sure you have a timestamp field in the person table, and that it is returned in your managers view. You also probably need the real PK of the person table in the manager view (I'm assuming your view takes the FK used for the self-join and aliases it as the ID field -- I wouldn't do that myself, as it is confusing. Instead, I'd use the real foreign key name in the managers view, and let the PK stand on its own with its real name).
try the Jet/ACE-specific DISTINCTROW predicate in your recordsource. With Jet/ACE back ends, this often makes it possible to insert into both tables when it's otherwise impossible. I don't know for certain if Jet will be smart enough to tell SQL Server to do the right thing, though.
if neither of those things works, change your form to use a recordsource based on your person table, and use a combo box based on the managers view as the control with which you edit the record to relate the person to a manager.
Ilya Kochetov pointed out that you can only update one table, but the work-around would be to apply the updates to the fields on one table and then the other. This solution assumes that the only access you have to these two tables is through this view and that you are not allowed to create a stored procedure to take care of this.
To model and maintain two related tables in access you don’t use a query or view that is a join of both tables. What you do is use a main form, and drop in a sub-form that is based on the child table. If the link master and child setting in the sub-form is set correctly, then you not need to write any code and access will insert the person’s id in the link field.
So, don’t use a joined table here. Simply use a form + sub-form setup and you be able to edit and maintain the data and the data in the related child table.
This means you base the form on the table, and not a view. And you base the sub-form on the child table. So, don't use a view here.