I am building a project to manage conferences. The database is on an SQL Server on an AWS instance and I am using MS Access as the front end.
I have a table for Events and a table for Exhibitors
These Tables have a relationship from Events.ID to Exhibitors.EventsID
One of my fields on the Exhibitors table is BoothNumber int Not Null
I would like to ensure that we cannot assign a booth number twice for the same event but have the ability to reuse the number for other (future) events.
Our booth assignment is generic: 1 -75 and this is repeated for every event.
Is something like this possible?
Thank you for your help!
If your data is on sql server, put a multi-field unique index on the table design using two or more fields. Sql server then takes care of the rest preventing duplicate entries.
Related
I'm trying to think of the easiest way for non-tech users to dump info into a database, without coding my own web application.
Essentially, they are recording subjective phone grading scores for employees.
I linked an Access form to our MS SQL Server database. The only validation I want it -- I want one field, 'employee' - to be validated against a list of employees from say table.employee on SQL Server.
Once the form is submitted it will be written to table.scorecard -- or what have you.
Is this possible in Access? Their standard validation rules don't seem to cover this. Also, is there simply a better way to accomplish this task in general? Thanks
There are two ways to solve this problem.
The simplest is to use a combobox field for your employee information. Use the employee table as the list data source for the combobox and then set the LimitToList property to true. This assumes that you have setup linked table connections for both your employee table and your 'scores' table.
The second solution is to create a foreign key between the employeeId (or whatever the key field is) in the scores table and the employee table on the SQL side. If someone tries to insert an invalid employee, you will get an insert error. Unfortunately, SQL errors tend to be very confusing to most Access users.
If you want to be very through, you could implement both solutions, this would prevent someone going straight to the linked tables and putting in bad data.
I just realized that I am assuming that you are doing proper relational design where the 'scores' table would contain the employeeId rather than a full name. The idea on the form is to have the combobox display the name, but insert the employeeid field.
I'm currently solving this task: some data should be sent from AdventureWorks2012 to Anchor model tables on the same server in MsSQL.
This is my Anchor Model
At this point I have a pretty simple Integration Services project in Visual Studio and it looks like this.
Control flow:
For example Load_territories is:
The main requirement is to fill all tables of Anchor model tables in MsSQL but I'm constantly facing a problem: the amount of attributes in tables are different and some of them are repeating
At this picture in the second table basically TR_ID,TR_GRP_TR_ID, TR_TID_TR_ID, TR_TNM_TR_ID contain the same values from dwh_key but it's impossible to create a one-to-many relation between attributes. My tutor has recommended me to use Lookup but I cannot figure out how to implement them in this project
This may be considered as cheating, but if you insert data into the latest view rather than the separate 6NF tables all of those ID fields will be populated by underlying trigger logic. I suspect that this would defeat the purpose of using SSIS though, since you would effectively be loading attributes sequentially rather than in parallel.
Another option is to leave surrogate key management to the ETL tool. This would require that you switch the data type for your identities from integers to GUID:s. SSIS can then generate a GUID and you can then use that very same GUID to populate all the attributes. Note that the anchor would have to be loaded first, or you will get a foreign key violation.
The most common solution though, is to leave surrogate key management to the database (and use integers). You would have a step in which you populate the metadata column in the anchor with the desired number of new identities to be created. Using the metadata number you can then select the newly generated identities and merge them into your data flow. It doesn't matter which number gets assigned to which row. After that all attributes can be populated in parallel, including their ID columns.
Of course, if this is intended to be used for more than an initial load, you would also have to add steps to detect if the data you are loading is already known or not.
I can also recommend watching the video tutorial referenced in this blog post: https://clinthuijbers.wordpress.com/2013/06/14/ssis-anchor-modeling-example-tutorial/
I am planning to move my access database to sql server using SSMA. I have a Column called Eligibility which have drop down list values as shown in Image. After Converting to sql I realized it doesn't have drop down list option. Can anybody suggest what will be the best solution of my situation? Either I can have any other option to design table in SQL which can hold List Values?
You can do one of the following:
Add CHECK constraint to Eligibility field allowing only a set of predifined values to be inserted into that field, as suggested in comment.
Better solution would be to create Eligiblity table (with id and value fields), and reference this table from main table by id field, possibly creating a PK-FK relationship. This way:
a) Only values from Eligibility table would be allowed. b) You could change and add entries in Elibility table without need to change constraint every time. c) A frontend application could use Elibility table to add drop-down functionality.
SQL Server does not work the same as access. It does not have dropdown option for you to choose from.
The proper way to implement dropdown option with SQL Server as database is to have another application as a front-end and let user access through the application. That way it is easier to manage security.
I am coding in ASP.NET C# 4. The database is SQL Server 2012.
I have a table that has 2000 rows and 10 columns. I want to load this table in memory and if the table is updated/inserted in any way, I want to refresh the in-memory copy from the DB.
I looked into SQL Server Change Tracking, and while it does what I need, it appears I have to write quite a bit of code to select from the change functions -- more coding than I want to do for a simple scenario that I have.
What is the best (simplest) solution for this problem? Do I go with CacheDependency?
I currently have a similar problem: I'm implementing a rest service that returns a table with 50+ columns and I want to cache the data on the client to reduce trafic.
I'm thinking about this implementation:
All my tables have the fields
ID AutoIncrement (primary key)
Version RowVersion (a numeric value that will be incremented
every time the record is updated)
To calculate a "fingerprint" of the table I use the select
select count(*), max(id), sum(version) from ...
Deleting records changes the first value, inserting the second value and updating the third value.
So if one of the three values changes, i have to reload the table.
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.