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!
Related
I'm not sure how to word the title properly so sorry if it wasn't clear at first.
What I want to do is to find users that have logged into a specific page, but not the other.
The table I have looks like this:
Users_Logins
------------------------------------------------------
| IDLogin | Username | Page | Date | Hour |
|---------|----------|-------|------------|----------|
| 1 | User_1 | Url_1 | 2019-05-11 | 11:02:51 |
| 2 | User_1 | Url_2 | 2019-05-11 | 14:16:21 |
| 3 | User_2 | Url_1 | 2019-05-12 | 08:59:48 |
| 4 | User_2 | Url_1 | 2019-05-12 | 16:36:27 |
| ... | ... | ... | ... | ... |
------------------------------------------------------
So as you can see, User 1 logged into Url 1 and 2, but User 2 logged into Url 1 only.
How should I go about finding users that logged into Url 1, but never logged into Url 2 during a certain period of time?
Thanks in advance!
I will try to improve the title of your question later, but for the time being, this is how I accomplished what you are asking for:
Query:
select distinct username from User_Logins
where page = 'Url_1'
and username not in
(select username from User_Logins
where Page = 'Url_2')
and date BETWEEN '2019-05-12' AND '2019-05-12'
and hour BETWEEN '00:00:00' AND '12:00:00';
Returns:
User_2
Comments:
I basically used a sub query to filter out the usernames you don't care about. :)
The time range is getting only 1 result, which you can test by removing the "distinct" in the first line of the query. If you then remove the time range from the query, you'll get 2 results.
You can do it with group by username and apply the conditions in a HAVING clause:
select username
from User_Logins
where
date between '..........' and '..........'
and
hour between '..........' and '..........';
group by username
having
sum(page = 'Url_1') > 0
and
sum(page = 'Url_2') = 0
Replace the dots with the date/time intervals you want.
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.
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 have a spreadsheet where dates are being recorded in regards to individuals, with additional data, as such:
Tom | xyz | 5/2/2012
Dick | foo | 5/2/2012
Tom | bar | 6/1/2012
On another sheet there is a line in which I want to be able to put in the name, such as Tom, and retrieve on the following cell through a formula the data for the LAST (most recent by date) entry in the first sheet. So the first sheet is a log, and the second sheet displays the most recent one. In the following example, the first cell is entered and the remaining are formulas displaying data from the first sheet:
Tom | bar | 6/1/2012
and so on, showing the latest dated entry in the log.
I'm stumped, any ideas?
If you only need to do a single lookup, you can do that by adding two new columns in your log sheet:
Sheet1
| A | B | C | D | E | F
1 | Tom | xyz | 6/2/2012 | | * | *
2 | Dick | foo | 5/2/2012 | | * | *
3 | Tom | bar | 6/1/2012 | | * | *
Sheet2
| A | B | C
1 | Tom | =Sheet1.E1 | =Sheet1.F1
*(E1) = =IF(AND($A1=Sheet2.$A$1;E2=0);B1;E2)
(i.e. paste the formula above in E1, then copy/paste it in the other cells with *)
Explanation: if A is not what you're looking for, go for the next; if it is, but there is a non-empty next, go for the next; otherwise, get it. This way you're selecting the last one corresponding to your search. I'm assuming you want the last entry, not "the one with the most recent date", since that's what you asked in your example. If I interpreted your question wrong, please update it and I can try to provide a better answer.
Update: If the log dates can be out of order, here's how you get the last entry:
*(F1) = =IF(AND($A1=Sheet2.$A$1;C1>=F2);C1;F2)
*(E1) = =IF(C1=F1;B1;E2)
Here I just replaced the test F2=0 (select next if non-empty) for C1>=F2 (select next if more recent) and, for the other column, select next if the first test also did so.
Disclaimer: I'm very inexperienced with spreadsheets, the solution above is ugly but gets the job done. For instance, if you wanted a 2nd row in Sheet2 to do another lookup, you'd need to add two more columns to Sheet1, etc.