Tables :: Empty Date Field - Using As Unique Identifier In Index?
Mar 5, 2013
To prevent duplicate records, I use multiple fields indexes, which worked fine until now. I learned that each "empty" fields are consider unique by Access, so not the best in an index to prevent duplicate records. I managed to have it worked using the default value property to give each "empty" records the same value.
Now my problem is that I have a date field which is optional, but I need to use it as a unique identifier in an index. I could again use a default value, but since it has to be a date, I find it confusing. I would rather have a default value of "No date specified" or "-" or even better, "". Unfortunately none of those works with date fields.
I am trying to create a one-to-many relationship between these two tables. I want to be able to access the 3 fields on the [Processors] table within reports based on [AllItems]. [AllItems] is a listing of account activity where the [AccountNumber] repeats. I have every field set as the "Primary Key" on [AllItems] as that is the only way to avoid importing duplicate data. I am getting the error: "no unique index found for the referenced field of the primary table"
Any way on a table that I can have a unique identifier over two fields? E.g.I have a login ID and a Domain field in a table with sample data below.
Login Domain
John Test Jane Test Fred Live John Live
The login names need to be unique to the domain so the integrity cannot be breached. This has to fit into one table (although the domain is actually being pulled from a look up table so is in fact a numerical value) for ease of form creation.
I'm currently in the process of doing a an overhaul of the database including a table, some odd 17,500 records long.
What I need to do is to create a unique identifier from the existing part number, almost like an autonumber, but it only increments when there are duplicates. What I mean is that there would be for example, there would be five records of say, part 000135.
What I'm trying to get at is, how I would have to code to grab the existing part numbers (all formatted to be 6 digits), add an extra 2 digits to be its unique identifier, and then save it all to a Unique Identifier column, that I created.
An example of what I want is say, I have part numbers 000135 and 000136. The numbers would go up from 000135-01, 000135-02, 000135-03, 000136-01, 000136-02.... The dash is not as important as implementing the 2 digit unique identifier.
I wonder if someone can help with what must be an easy solution to this problem.
I have a table with 350,000 records, but without a unique identifier field. I just want a simple incrementing number field to become the primary key but dont know how to add this in. I cannot add an autonumber as there are two many records - it falls over.
Ive tried exporting it all to excel, but as well as being cumbersome, something went wrong and so I'm back to square one.
I think there must be a way to add an incrementing number either via a query or in VBA but I dont know how. Please can somebody provide a solution.
Have a table with data in it and I want to add a new field to uniquely identify each record (simple numerical sequence like 1, 2, 3, 4.....). I don't know VBA and don't know SQL.
Tried opening the table in design view, adding a new field with "autonumber" as the data type but get the following error msg: "File sharing lock count exceeded. Increase MaxLocksPerFile registry entry". The table has about 750,000 records in it.
I am building a database to capture monthly statistics on a number of items. I want to ensure that users don't enter statistics for the same item for the same reporting period. I found the following instruction, but can't make it work:
It suggests that I create multiple primary keys in the table
When I do it, it comes back with an error: Index or primary key cannot contain a null value.
I am trying a to build a slot booking database in which users will be able to book slots (ranging from 1-30) on a particular day for a specific site (location).
When trying to build the relationship between slot in tbl_available and slot in tbl_appointment i get the following error "No unique index found for the referenced field of the primary table" the same error pops up when trying to build a relationship between site in tbl_available and site in tbl_appointment.
I'm looking into create a small unique identifier to put on top of each invoice generated by the database. (.MDB A2010)where '000' its just 3 zeros added for extra badassery, '1' is the actual ID from the database table and -2014 its the current year when the record was added...So maybe I have info from 2 fields (ID, YEAR)... but How do I add the ceros to the ID field... so its 0001 not 1 or 0135 not 135... ???.
I have a database in Excel that contains farmers who can be identified by a Unique identifier: MZ-01-0001. The registration details for these farmers are not always up to date. Now when I try to append the data for the farmer with MZ-01-0001; with the primary key set on the Unique identifier, Access does not want to do it since there is already a record in the system. When I remove the primary key it doubles the record, which is also not what I want. So I am wondering what I need to do to append the record while keeping the primary key intact.
I have a large table with information about different cars, called "Car Metadata". In this, each car has a unique identifier ("Car Code"), the make ("Manufacturer Name") and the model ("Short Model").
What I want to do is create a form with dropdown menus.I have a first combo box with all the makes in the Metadata table.
What I am having trouble with is that I want a second combo box underneath which would only show the models which correspond to the make selected in the first box.E.g. someone could select Ford in the top box and the second box would only show Fiesta, Focus etc.
Once it has done that I want it to be able to write the Car Codes for the records which match up to the make & model selected to a new table. Just to complicate things further, there can be multiple records with the same make and model but different Codes, I want all these multiple codes to be written to the final table.
So i have a access database with a main field that we can call vendor # (LIFNR) and another called Company code (BUKRS). There are multiple company codes under a single vendor #. Example:
LIFNR BUKRS
0000010535 1010
0000010535 5060
0000010535 5610
0000010536 1010
0000010536 5060
0000010536 5610
What I am trying to do is create a 3rd column where i can have a unique row for each of these fields without it repeating. There is no unique identifier in this table and that is what i am trying to achieve.
How to get this one to display in a single column.
I know how to do this wiht VBA. But, this output will need to reside on a SQL Server View. So I need a SQL language solution. If it can work in MS Access Query, it won't be too difficult to test then translate to SQL Server.
Customer Table with PK Customer_ID.
There are two tables with FK Customer_ID.
1. Table Lease1 - Has 3 Fields - the form code enforces No Fields -or All Fields. The red * indicate a Required field - These 3 are entered together.
2. Table Lease2 - Has 1 field with 0 to Many records.
Goal:
The Type shows up in a single column.
Each Type shows where the data comes from (Lease Type, Surface Owner, Mineral Owner, or Hz Lease Type)
Challenge:
Lease1 table has 3 fields that need to be transformed into a single column.
Lease2 table has 1 field to be appended to the single table.
Then, there is the column that identifies where the data came from based on the column name.
Can't figure out why I can't create a one to many relationship between two tables:
TableA uses a composite key as its primery key (field1, field2). The table has a unique index comprised of these keys. The index even has a name. The table also doesn't contain any duplicate information, so the fields comprising my Primary Key are unique. The table I'm joining tableA is unpopulated at this time.
Hi, I'm not sure where to post this, maybe VBA or Forms would be better, but I think it's fundamentally an index problem, so I'm posting here. I've searched both the net and here, but most of the questions are about preventing duplicate records.
I want to prevent duplicate records but save changes to existing records.
I have a form based on a table that has a 3-field-unique-index (but not the primary index, which is autonumber). I've written a function to check for existing records with the given combination of the three fields, as long as all have data (it bails if any are null). I'm calling the function from BeforeUpdate for each of the textbox controls. I was also calling it from the form's BeforeUpdate, but commented it out as it seemed redundant. I have other code there verifying that the user wants to keep the changes.
I'm trying to save the users from getting all the way to the end before discovering there's a problem. To test it, I added then deleted one character from one of the three relevant fields in an existing record, and bing, up pops my alert that I'm violating the index. Then I can't leave the field, I'm stuck there because I can't save the record.
I want it set up so that other fields in the record can be changed/updated AND so that a new record for the same person can't be entered (a dupe).
Oh, and I'm running into all kinds of problems with acCmdSaveRecord not being available. I feel like an idiot that I haven't been able to make sense of the posts about that. I can just comment it out and let Access save the record when it closes the form. But my bosses really want the users prompted about saving changes.
Any thoughts or suggestions or insights greatly appreciated. I really tried to search this out, so any tips for better searching are also appreciated.
Here's the code for the function:
Public Function CheckForClientDupes() Dim response As Variant Dim strFamID, strLName, strFName As String Dim strFilter As String
If IsNull(Me!FamilyIDNo) Or IsNull(Me!strLastName) Or IsNull(Me!strFirstName) Then Exit Function End If
response = MsgBox("There is already a client with this combination of FamilyID, Last and First names in this database. Would you like to Continue Anyway (Yes) or cancel data entry and Erase Your Changes (No)?", vbYesNo, "Duplicate Client Alert") If response = vbYes Then ' DoCmd.RunCommand acCmdSaveRecord Else response = MsgBox("You have chosen to cancel your changes. Your changes will be erased.", vbOKCancel + vbQuestion, "Data Entry Cancelled") If response = vbOK Then Me.Undo Else Exit Function End If End If End If
I have a couple of tables which only have a single field. Is it worth adding a second field in order to hold an ID number (is this commonly termed an index number?) for each entry.
My other tables with multiple fields include a field for an ID number and these tables are linked via these fields.
At this stage I cannot see any reason why, in the future, I would want to add additional fields to the tables which I am currently planning to make single field.
I am using the QBE grid and am writing a select query to select only records with an empty Date Closed Field. The Date Closed field is a Date/Time Field. I am using Access 2003. When I use in the criteria IsNull([DateClosed]) I do not get any records selected which have an empty Date Closed field, have I a bug? and if so please could anyone point me in the right direction.
I have a table called SWAPS which contains information on each user and the different equipment he has been issued. Query at the moment contains 5 fields
Payroll, Surname, Firstname, Mobile No and Date sent.
SQL for this query is as follows
Select Swaps.PR, Swaps.surname,swaps.firstname,swaps.[mobile no],Max(Swaps,[Date Sent] as Lastdate
From Swaps
Group by swaps.pr, swaps.surname,swaps.firstname,swaps.[mobile no]
Order by swaps.pr;
Now when I run this I get the results I want by date so I get
123456 Smith Fred 0788411025 12/3/8
456789 West Bob 012555447854 13/1/8
So it correctly ids all the last dates for me as I want to see the latest issue date for that user. Now I want to add in another column to this query which contains the serial number of the equipment issued and heres where the problem lies. If a user has been issued more than 1 piece of kit, I get all the serial numbers irrespective of date. How do I get it to display the serial number for the latest date?
What I want to do is create a new field that automatically populates based on what is entered into the above fields.
Essentially creating a single field with unique data generated by multiple fields.
For Example if I entered the following informaiton: EmployeeID: 1 (AutoNumber) FirstName: John MInitial: P LastName: Doe Company: FederalGov Department:Test
The new field can be generated as followed: JohnPDoeFederalgovTest
What i plan on doing with this is making this "generated" field an index so no new duplicated records can be added.
I have downloaded a contact template from the internet ready to go. There are few things I need to get rid off and make changes to.
One of the most improtant thing is making one of the field unique. For some reason, i can get to the design view. I open navigation panel and right click on the table, there is no such thing call design view on the menu.
I have 4 fields in a table that when combined must be unique.I know you can setup multiple fields as a combined key, but I don't really need these to be the key (I will auto number a unique key). I just need to make sure the same combination of codes is not entered twice.Do I set this up as multiple key fields anyway?
