I have a table in the database that store 4 category and the structure of the table is ID (GUID), description. I load the category into a dropdown list (asp.net webform) to allow people to select a category and based on what they selected. I'll then display info associated with their selection and hide the others.
Currently, i do a "select case" based on the GUID that i hard coded in code behind to display the associated info. Is there a better way to do this without hard code in GUID on the code behind?
What is the Data that's associated with the Guid/Description...
The data you've hardcoded sound's like a candidate for being added to the database itself.
If it's one piece of information per Category/Guid, then consider extending your Database Table to store that info to.
If it's multiple piece of information per Category/Guid, then consider creating a new Table With a CategoryID on it, and a foreign key relationship between your Category Table and your ExtraInfo table
You could query the database for the GUIDs when the app starts and cache them in a static Dictionary.
you could store the GUID in your web-config and load it at run time. then, you can easily replace that GUID with another w/o having to recompile.
You should have a Categories table and a Posts table (or whatever it is that you will tag with your categories). In the Posts table you have a column for the CategoryID (assuming each post can only belong to one category), so that you only have the category name in one place (normalize your data).
When you render the dropdownlist, you select the GUID:s from the database. No hard coding, and if you add another category (or remove one) the dropdownlist will automatically reflect the available categories.
If you bind the dropdown list to the Category row or a Tuple that contains the category name and the value you can load the Guid in your codebehind using the SelectedValue property. You will then set the DataTextField and DataValueField on the Dropdownlist.
Related
I have a multi-select widget bound to a table that only contains relations. I want to use the related values for each record to populate the multi-select name.
Parent-Table
- Child-Table-One
- Child-Table-Two
No matter which way I try using the multi-select name paths, only the first record name in the multi-select gets populated with the related value from the related child table, the others just display the record ID of the Parent Table.
Do I need to use a function somehow to iterate through all records to get the related values for every record?
Binding to the Relation should get you a list of records. Assuming you're trying to get list of the display names, this should work:
(#datasource.item.Child1).concat(Array.from(#datasource.item.Child2))
I am trying to implement a Many-to-Many relation between a class and its students in a form.
The form can be used to create or edit a class. Also students can be added to that class. To reduce the effort needed to enter students, I would like to add a multi-select that shows the entries from the students-table. But since the number of students is expected to be large, I would like to filter this multi-select.
I checked this question on filtering lists and the sample app "Project List. I understand that the standard workflow with a table would be to bind the value of a search box to the #datasources.STUDENTS.query.filters.email._contains and set the tables datasource property to STUDENTS
But, as I understand it, a multi-select element's value property must be bound to #datasource.item.students and its datasource property must be CLASS in order for the auto-saving to work.
Hence I wonder whether it is possible to filter a multi-select element.
I don't see the problem, but I think I see a misunderstanding.
You said: "I understand that the standard workflow with a table would be to bind the value of a search box to the #datasources.STUDENTS.query.filters.email._contains"
You need to bind the OPTIONS (not value) to the datasource query, as it is the options that will draw its records from the #datasources.Students.query datasource.
You can then set the VALUE of the multi-select widget to #datasource.item.students (where you want selected values from the student query options to be saved).
You will also need to set the NAMES property (since the options are likely student records). Names will be the Student datasource projection of whatever string field you want to appear in the options list.
I am trying to create a report putting a field called contact which has the name of a person. This name is linked directly to another table where I keep all the contacts.
For some strange reason, when I include this name (which in query view displays as the name of the contact), instead of the name appearing, the unique ID number is shown on my report.
As mentioned in the article cited in the above comment, you can use a Combo Box control on your report to do the lookup for you. To see how this can be done, create a new report based on the table containing the lookup field, then drag and drop that field onto the report. That will create a Combo Box control with properties that look something like this:
Row Source: SELECT [Clients].[ID], [Clients].[LastName] FROM Clients;
Bound Column: 1
Column Count: 2
Column Widths: 0";1"
You could use a similar Combo Box control on your actual report to display the client's name rather than their numeric ID value.
Another alternative would be to change the Control Source of the report's Text Box control to have it do a DLookUp() on the table. If the lookup field is named [client] then changing the Control Source of the Text Box to something like
=DLookUp("LastName","Clients","ID=" & [client])
would also work.
I wanted to add to the great answer by Gord:
When using a "web" database (started in Access 2007 I think), you cannot change a report's fields to ComboBox style, nor can you use DLookUp(). (web databases lack a ton of features)
The workaround for this, if you want to create a Web-Report that uses lookup fields, is to create a Web-Query first based on your Web-Table (all the Web-* stuff has a www planet icon over the logo, if you create a new Web-DB in Access 2007+ you'll see what I mean)
So, instead of Table -> Report, you'll have to do W-Table -> W-Query -> W-Report.
Then, the only thing you need to customize to get the data right is the W-Query. Start by trying to reproduce the look in the query to match what you want users to see in the report. Note that here in the query, lookups will work fine (instead of the unique ID's, you get field names like you want). However, this will not carry over to the report. To do that, you gotta get the actual text field name you want into the query:
You should already have one table in your query; start by adding the table that your first lookup field points to. For example, the table I want to print is called Stock_Boards, and it has a lookup field called PCBID_lookup that points to the table Stock_PCBs.
Since you're using lookup fields, there should already be a relationship line between the two tables when you add the second one. If there isn't, something has gone horribly wrong.
Now, see how that line connects two fields on the two different tables? For example, I've got my PCBID_lookup field on my Stock_Boards table, which connects to the ID field on my Stock_PCBs table. If I created a report from this now, PCBID_lookup would be a number, a number that correlates to the ID of a record on Stock_PCBs.
To fix it, I will add the name field I want to show up on the report. In my example, that happens to be a Part Number, rather than the ID. I add the PartNumber field from my Stock_PCBs table to the query, and remove the PCBID_lookup field of the Stock_Boards table from my query.
Since PartNumber is what I want to show up on my report, it effectively replaces the original field (PCBID_lookup)
Repeat for all lookup fields you want in your report.
I had 1 more: I removed the Status field of the Stock_Boards table (which was an ID/Lookup) and added the 'Status' field from the Status table (which was the actual text name)
When finished, your query should look exactly how you want the data to appear, without any special tricks or asking Access to do something unnatural. Save your query, and create a web-report from it. Done!
I have a GridView control that gets data from two tables, the first one contains a primary key, a name (string) and a foreign key to the second table, The second table contains a primary key "referenced by the foreign key mentioned" and a name (string), i was able to display the id, name (first table) and the name (second table) using an inner join but i can't update the data in the tables using the GridView (when pressing update nothing happens at all, or no change occurs).
From what i understand of your question what you have is a situation that you must a apply a nested gridview.
A gridview shows the content of a table (datatable or a collection).
If you want to show other collection that is inside each row of your primary gridview, you will need
to build a second Gridview or listview or repeater to show that information.
with the primary griview you can use the OnItemDataBound to assign the datasource of the nested gridview or what you choose to show that information based in primary key of the row.
Don't bother i found a solution to the problem on Microsoft website, i am sorry i didn't make my question pretty clear and here is a link to what i was looking for: Editing with Template Fields
Maybe after clicking Update you need to call your read method again to refresh your gridview.
something Like:
UpdateMethod()
{
//YOUR UPDATE STUFF
//REBIND DATA WITH UPDATED RECORDS
RefreshMethod(); //YOUR BINDING METHOD TO DATAGRID STUFF
}
I'm building out a schema for a site that will need to store a product's currency. I'm not sure whether I'll be needing to be able to convert from one currency to another, however, I'm presuming that will probably be necessary. My db schema is below. (this is for a mobile app btw). My question is, should I just simplify things by adding an additional column called currency to my item table? Does my design make sense? Thank you.
Edit (based on reply from Victor below): the items have a many-to-many relationship with order table. How about putting the currency id on order table since most likely all items in an order will be in the same currency?
exchange_rates
id
currency_from
currency_to
ex_rate
item_currencies
currency_id
item_id (from items/products table)
currencies
id
code
symbol
The schema looks good but I think that the *item_currencies* table is not necessary.
In your items table you can just add the currency_id column. Keep it together with all the item properties :)