I have a DevExpress.XtraGrid. I want the user to edit one of the columns and, after the edit is made, for the grid to update the value of another column. I tried using the event CustomRowCellEdit, but it threw an error whenever I added that event; I wasn't sure how to change the value of another cell anyway. Can someone explain how to do this?
So I've got a grid like this:
----------------
| A | B | C |
----------------
| 1 | 50 | 100 |
----------------
| 2 | 20 | 40 |
----------------
| 3 | 10 | 20 |
----------------
Let's say the user edits row 1, column B to be 25. After they make the change, I want row 1, column C to be twice what B is. So the end result is below where B1 is the value that is user entered and C1 is calculated based on the value in B1.
----------------
| A | B | C |
----------------
| 1 | 25 | 50 |
----------------
| 2 | 20 | 40 |
----------------
| 3 | 10 | 20 |
----------------
I tried this:
private void myView_CustomRowCellEdit_1(object sender, DevExpress.XtraGrid.Views.Grid.CustomRowCellEditEventArgs e)
{
string newValue = e.CellValue.ToString();
int index = myView.GetDataSourceRowIndex(e.RowHandle);
myView.SetRowCellValue(index, "B", newValue);
}
but I don't think the "B" referred to the column correctly and I got a run time error with a null reference exception.
The GridView.CustomRowCellEdit event is intended to assign repository items to grid cells conditionally. For your case, it is necessary to handle the GridView.CellValueChanged event instead.
Refer to the Modify and Validate Cell Values help topic for more information.
Related
I'm trying to update a table column from another table with the code below.
Now the editor says '39 rows affected' and I can see something happened because some cells changed from null to empty (nothing shows).
While orhers are still null
What could be wrong here?
Why does it not update properly....
PS: I checked manually that the values are not empty in the column to check for.
UPDATE CANZ_CONC
SET EAN = (SELECT t1.EAN_nummer FROM ArtLev_CONC t1 WHERE t1.Artikelcode_leverancier = Artikelcode_leverancier)
WHERE ARTNMR IN (SELECT t1.Artikelcode_leverancier FROM Artlev_CONC t1 WHERE t1.Artikelcode_leverancier = ARTNMR);
Edit:
The tabel2 is like:
NMR | EAN | CUSTOM
-------------------------------
1 | 987 | A
2 | 654 | B
3 | 321 | C
Tabel 1 is like
NMR | EAN | CUSTOM
-------------------------------
1 | null | null
2 | null | null
5 | null | null
After the UPDATE table1 is like
NMR | EAN | CUSTOM
-------------------------------
1 | | null
2 | | null
5 | null | null
I've got this working.
I guess my data was corrupted after all.
Since it is about 330.000 rows it was not very easy to spot.
But it came to me when the loading of the data took about 10 minutes!
It used to be about 40 - 60 seconds.
So I ended up back at the drawing board for the initial csv file.
I also saw the columns had not been given a DATA type, so I altered that as well.
Thanx for the help!
I'm required for designing a survey system for our customer.
It's based on asp.net, and the database used is oracle.
I've no experience here so I'd like to ask for advice about:
What database schema to use for storing user answers, I'm afraid my current design is likely to have performance issue...
About the survey:
There'll be two or more surveys going on at the same time.
Surveys may be triggered once a year or more frequently, so I think I need a Survey Period table.
Surveys are targeting different products, so there'll be a mapping between products and surveys
Currently my design:
Survey Category table
+------------+--------------+
| CatageryId | CatageryName |
+------------+--------------+
| 1 | cat1 |
| 2 | cat2 |
+------------+--------------+
Survey Category version table
+-----------+------------+--------------------+
| VersionId | CatageryId | VersionDescription |
+-----------+------------+--------------------+
| 1 | 1 | 'cat1 version1' |
| 2 | 1 | 'cat1 version2' |
| 3 | 2 | 'cat2 version1' |
+-----------+------------+--------------------+
Survey Period Table
+----------+--------------------+
| PeriodId | PeriodDescription |
+----------+--------------------+
| 1 | 'cat1 period2016' |
| 2 | 'cat1 period2017' |
| 3 | 'cat2 period2016' |
+----------+--------------------+
Survey Period-Version map table
+----------+-----------+
| PeriodId | VersionId |
+----------+-----------+
| 1 | 1 |
| 1 | 2 |
| 2 | 1 |
| 3 | 3 |
+----------+-----------+
A Version-Question map table
+--------------+------------+
| VersionId | | QuestionId |
+--------------+------------+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
| 2 | 1 |
| 2 | 2 |
| 3 | 1 |
+--------------+------------+
A Version-Product map table
+-----------+-----------+
| VersionId | ProductId |
+-----------+-----------+
| 1 | 'prodA' |
| 1 | 'prodB' |
| 1 | 'prodC' |
| 2 | 'prodA' |
+-----------+-----------+
And to Store the survey result data, I have to put lots of duplicated information between rows of record:
User Answer table
+----------+------------+----------+-----------+-----------+--------+-----------+
| AnswerId | QuestionId | PeriodId | UserId/Ip | ProductId | Answer | VersionId |
+----------+------------+----------+-----------+-----------+--------+-----------+
| 1 | 1 | 1 | 'adam' | 'prodA' | 'Yes' | 2 |
| 2 | 2 | 1 | 'Joe' | 'prodA' | 'Yes' | 2 |
| 3 | 1 | 2 | 'adam' | 'prodB' | 'A' | 3 |
+----------+------------+----------+-----------+-----------+--------+-----------+
We're expecting tens of products and thousands of users for this system.
So assume 30 products, 5000 users, 50 questions per survey and 4 surveys per year
in the current design, there'll be 5000 * 4 * 50 * 30 = 30 millions of records added in the User Answer Table per year,
I'm really afraid if it could still work properly..., so any suggestions for optimizing?
Edit 1:
Add VersionId column in user answer table as suggested.
This looks like a case of premature optimization. You should probably worry more about correctness and flexibility than performance.
30 million rows per year, especially in these skinny tables, is a small amount of data for any Oracle system. Don't worry too much about indexes and partitioning yet, those can be added later if necessary.
Your solution is similar to the Entity Attribute Value (EAV) model. It's worth knowing that term since much has been written about it. There are 2 common problems with EAV models you want to avoid:
Avoid extremes. Don't use EAV for everything, but don't completely avoid it either. EAV is slow and inconvenient compared to a normal table structure. It should not be used for every interesting columns, otherwise you have created a database within a database. For example, if virtually every survey has fields like a username and a date created, store those as regular columns and not in a generic column. It's OK to have a column that is only populated 99% of the time. On the other hand, it's a bad idea to always avoid the EAV and try to hack something together with 1,000 column tables or object-relational types.
Always use the correct type. Always, always, always store data as the correct type. Store numbers as numbers, dates as dates, and strings as strings. Your queries will be easier, faster, and safer, if you have at least three columns for the data: ANSWER_NUMBER, ANSWER_STRING, ANSWER_DATE. I explain the type safety problem more in this answer. Those extra columns may look bad in the model diagram, but they are a life-saver when you're querying the data.
I have two tables
Names
id | name
---------
5 | bill
15 | bob
10 | nancy
Entries
id | name_id | added | description
----------------------------------
2 | 5 | 20140908 | i added this
4 | 5 | 20140910 | added later on
9 | 10 | 20140908 | i also added this
1 | 15 | 20140805 | added early on
6 | 5 | 20141015 | late to the party
I'd like to order Names by the first of the numerically-lowest added values in the Entries table, and display the rows from both tables ordered by the added column overall, so the results will be something like:
names.id | names.name | entries.added | entries.description
-----------------------------------------------------------
15 | bob | 20140805 | added early on
5 | bill | 20140908 | i added this
10 | nancy | 20140908 | i also added this
I looked into joins on the first item (e.g. SQL Server: How to Join to first row) but wasn't able to get it to work.
Any tips?
Give this query a try:
SELECT Names.id, Names.name, Entries.added, Entries.description
FROM Names
INNER JOIN Entries
ON Names.id = Entries.name_id
ORDER BY Entries.added
Add DESC if you want it in reverse order i.e.: ORDER BY Entries.added DESC.
This should do it:
SELECT n.id, n.name, e.added, e.description
FROM Names n INNER JOIN
(SELECT name_id, description, Min(added) FROM Entries GROUP BY name_id, description) e
ON n.id = e.name_id
ORDER BY e.added
I've looked all over for answers on how to do this, including dozens of answers on Stack Overflow that provide almost but not quite solutions.
I am trying to make a table/list with a number of options. Imagine a table with the following columns:
Delete: A simple icon. This must be a fixed width (because it uses an image)
Name: The name of the item in the list. This should fill the remaining available space, but if the text overflows, I want the ellipsis to appear.
Options A/B/C: You can imagine these are check boxes and also are a fixed with.
So on a wide table it'd look like this:
| X | Item 1 in the list | A | B | C |
| X | Item 2 | A | B | C |
| X | Item 3 has a pretty long name | A | B | C |
| X | Item 4's name is long, realll... | A | B | C |
And on a short table (or say, after the window resized):
| X | Item 1 in the list | A | B | C |
| X | Item 2 | A | B | C |
| X | Item 3 has a pretty... | A | B | C |
| X | Item 4's name is... | A | B | C |
If someone could provide a fiddle showing this in action, that'd be absolutely fantastic.
EDIT: Thank you so much Plymouth!
I've created a fiddle here.
These are the important styles:
table
{
table-layout:fixed;
}
.col2
{
width:auto;
text-overflow:ellipsis;
white-space: nowrap;
overflow: hidden;
}
Is this what you're after?
+----------+------------+------+------+--------------+---------+---------+
| | SUBJ | MIN | MAX | RESULT | STATUS | PERCENT |
| +------------+------+------+--------------+---------+---------+
| | Subj1 | 35 | 100 | 13 | FAIL | 13.00% |
|EXAM NAME | Subj2 | 35 | 100 | 63 | PASS | 63.00% |
| | Subj3 | 35 | 100 | 35 | PASS | 35.00% |
| +------------+------+------+--------------+---------+---------+
| | Total | 105 | 300 | 111 | PASS | 37.00% |
+----------+------------+------+------+--------------+---------+---------+
This is my report viewer report format.The SubTotal row counts the
total of all the above column.Every thing is fine. But in the status
column its showing Pass. I want it to show fail if there is single
fail in the status column. I am generating Status if Result < Min then
it is fail or else it is pass. Now how to change the SubTotal row
below depending upon the condition. And is there any way to show the
Subtotal row directly from database. Any suggestion.
The easiest way to do this would be to use custom code (right-click non-display area of report, choose Properties and click the Code tab) - calculate the pass/fail score in the detail, display it in the group footer and reset it in the group header:
Dim PassFail As String
// Reset Pass or Fail status in group header
Public Function ResetAndDisplayStatusTitle() AS String
PassFail = "PASS" // Initialise status to pass
ResetAndDisplayStatusTitle = "Status"
End Function
// Calculate pass/fail on each detail row and remember any fails
Public Function CalculatePassFail() As String
Dim ThisResult As String
// Calculate whether this result is pass or fail
If Fields!Result.Value < Fields!Min.Value Then
ThisResult = "FAIL"
Else
ThisResult ="PASS"
End If
// Remember any failure as overall failure
If ThisResult = "FAIL" Then PassFail = "FAIL"
CalculatePassFail = ThisResult
End Function
Then you tie in the custom code to your cells in your table as follows:
In the value for the status column in your group header you put:
=Code.ResetAndDisplayStatusTitle()
In the value for the status column in the detail row you put:
=Code.CalculatePassFail()
In the value for the status column in the group footer you put:
=Code.PassFail
With respect to getting the subtotal row from the database directly from the database, there are a couple of ways depending on what result you are after.
Join the detail row to a subtotalling row in your SQL (so that the subtotal fields appear on every row in the dataset) and use those fields.
Again, use custom code (but this is probably overly complicated for subtotalling)
However, these tricks are only for strange circumstances and in general the normal out-of-the-box subtotalling can be tweaked to give the result you are after. If there is something specific you want to know, it is probably best to explain the problem in a separate question so that issue can be dealt with individually.