This query is supposed to run with ms access 2003 using SQL. the function JOIN is NOT supported explicitly. implicitly in the WHERE clause is fine...implicity anywhere is fine as long as the word JOIN INNER JOIN Etc is not used.
DayNumnber PastTime
.
.
.
333 Homework
333 TV
334 Date
620 Chores
620 Date
620 Homework
725 Chores
725 Date
888 Internet
888 TV
.
.
.
Hey I would like a query that can Show the most important past time done for each day (TV and internet do not count!) .So importance would be Homework > Chores > Date.So:
DayNumber PastTime
333 Homework
334 Date
620 Homework
725 Chores
Something that might change this problem. Altho all the different past times are listen in a table together. but that was because i appended the table. originally the homework entries. chore entries and date entriess . internet entriess. tv entries. came from different tables.
eg homework 333
homework 620
Is it easier to do it without appending these tables first? I would hopefully like it to be done with the appended table but ya
I was thinking of a mixture of insert. delete... but the hardest part is checking that there is something there for a date a few things and how to put the more important thing done that day . Thank you
Create another table with:
Pri | PastTime
--------------
1 | Homework
2 | Chores
3 | Date
This is a priority list for the items.
Next do:
SELECT MIN(Pri), DayNumber
FROM PastTime_table, Priority_table
WHERE PastTime_table.PastTime = Priority_table.PastTime
GROUP BY DayNumber
This will give you the most important past time for each day. And because TV and Internet are not listed they will not show up.
But it will give you a number, and not the name.
If you had a better SQL you could then join this back to the Priority_table and lookup the name. But I guess you will have to do that part manually.
If you are willing to change the name and call them:
A_Homework
B_Chores
C_Date
instead then you could do (without any extra table):
SELECT MIN(PastTime), DayNumber
FROM PastTime_table
GROUP BY DayNumber
Since it sorts the name alphabetically it will always give you the best one.
You can add a WHERE to remove TV and Internet.
Related
I am quite a novice in programming and I kind need your help regarding SQL and an issue I notice.
I have a table:
date, ID, secondary ID, expenses
jul2020 258 0004 1000
jul2020 xxx xxxx xxx
...... .... .... .....
aug2020 258 0008 2000
aug2020 xxx xxxx xxx
aug2020 500 0004 1000
Id and secondary should be unique and always matching. But I notice that they are not. It's either correct the ID or the secondary ID. I want to sum all the D column per unique ID.
Thanks for reading and if you have any ideas would be very helpful
UPDATE: everything is numeric even ID. It's like this. As you can see we have different dates (but for the same date multiple customers). I notice that customer 258 for secondary ID 0004 during the years the ID or the secondary ID changes. And I wan to assign the same ID as the first date and the same secondary ID as the first date ( or any day just to be consistent). I want to to do this cause I want to know how many expenses each customer has during the years. There are like 50m obs.
In my table I have a list of companies and several fields including a note field. I am attempting to remove duplicates with the same company name and adjusting the information as needed for the rest of the fields using the totals: Group As, Max and Min.
This works on all the fields except the note field and is causing two companies to come up twice since I cannot merge the note field. The note field is a Long Text data type and when I change it to Short Text data type it works and I can do the merge, however it looses a significant part of the note which I need to keep. How can I use a Max function with long text or is there another way around this?
Below is an example:
ID CompanyName Notes
123 CompanyA
124 CompanyA Long note goes here.
126 CompanyB Note here
234 CompanyC
My Goal is to get it to look like this:
ID CompanyName Notes
123 CompanyA Long note goes here.
126 CompanyB Note here
234 CompanyC
You should probably not use MAX on a text field to eliminate duplicates, because it may pick a wrong item for you. For example, if you feed 'A very good and long note' and 'Stub' to a MAX, it would prefer 'Stub', because it is higher lexicographically.
Perhaps you want to apply MAX to the length of the note, rather than the note itself. If you do that, you could find duplicates with a simple query:
SELECT c.ID as dup_ID, c.CompanyName as dup_name, c.Notes as dup_Notes
FROM Company c
WHERE EXISTS (
SELECT *
FROM Company oc
WHERE oc.CompanyName = c.CompanyName AND LEN(c.Notes) < LEN(oc.Notes)
)
Short background: I have an SQLite database, a couple of gb in size and growing. It contains a bunch of very simple tables. Each table consists of a 64-bit integer primary index field (TStamp) and a value field (Val). The field TStamp is actually an long-int representation of a date-time. The tables have widely varying row-counts and somewhat variable content types, but that shouldn't matter. A master table (tbIndDate) holds a full range of dates, has the same primary index (TStamp) as the other tables, and holds human-readable date-time in its Val field. For instance,
The master index table, named tbIndDate:
TStamp Val
634082688000000000 5/1/2010 0:00:00
634082691000000000 5/1/2010 0:05:00
634082694000000000 5/1/2010 0:10:00
634082697000000000 5/1/2010 0:15:00
etc etc
A sample table for automation tag 6FI1.PV, named tb6FI1%PV:
TStamp Val
634085793000000000 41.7
634085796000000000 42.83
634085799000000000 41.44
634085802000000000 40.43
634085805000000000 39.78
etc etc
Getting data into the tables is handled by a little vb.net program, and when a new automation tag is added to the capture list then the program creates a new table using the automation tag name, and begins populating it. That all works real slick.
OK. I've started building a tool for getting data out of the database. It works great for inner joins:
SELECT [tbIndDate].[Val] AS 'Timestamp',[tb6FI1%PV].[Val] AS '6FI1.PV',
[tb6FI34%PV].[Val] AS '6FI34.PV',[tb6AI32%PV].[Val] AS '6AI32.PV'
FROM [tbIndDate],[tb6FI1%PV],[tb6FI34%PV],[tb6AI32%PV]
WHERE [tbIndDate].[TStamp]=[tb6FI1%PV].[TStamp]
AND [tbIndDate].[TStamp]=[tb6FI34%PV].[TStamp]
AND [tbIndDate].[TStamp]=[tb6AI32%PV].[TStamp];
This returns:
Timestamp 6FI1.PV 6FI34.PV 6AI32.PV
1/1/2013 0:00:00 42.4679 1.499 0.8439
1/1/2013 0:05:00 40.3628 1.5048 0.8435
1/1/2013 0:10:00 38.2652 1.5028 0.8436
1/1/2013 0:15:00 37.8582 1.5029 0.8436
Yay! :)
I've also gotten some averaging and time-interval queries working.
However, because tag data is not all available for all dates, I'd like to create the option to list all dates in the master index even if some of the tag tables do not have matching data.
A SELECT query with a left outer join, in other words. Everyone knows that. The data might look like:
Timestamp 6FI1.PV 6FI34.PV 6AI32.PV
1/1/2013 0:00:00 42.4679 1.499 NULL
1/1/2013 0:05:00 40.3628 1.5048 NULL
1/1/2013 0:10:00 38.2652 NULL NULL
1/1/2013 0:15:00 37.8582 NULL 0.8436
Trouble is, none of the SQL I've tried has worked. Here's one that didn't go:
SELECT [tbIndDate].[Val] AS 'Timestamp',[tb6FI1%PV].[Val] AS '6FI1.PV',
[tb6FI34%PV].[Val] AS '6FI34.PV'
FROM [tbIndDate],[tb6FI1%PV],[tb6FI34%PV]
LEFT JOIN [tbIndDate] ON [tbIndDate].[TStamp]=[tb6FI1%PV].[TStamp]
LEFT JOIN [tbIndDate] ON [tbIndDate].[TStamp]=[tb6FI34%PV].[TStamp];
The error was "SQL error or missing database, ambiguous column name: tbIndDate.Val"
I've tried copying the syntax from several examples, but none are exactly the same and my attempts fail.
Am I doing the aliases wrong? The square brackets to accommodate special characters in table names? I'm a complete SQL beginner, so don't hold back with the advice.
It looks like the problem is that you're trying to join [tbIndDate] several times. Try this:
SELECT [tbIndDate].[Val] AS 'Timestamp',[tb6FI1%PV].[Val] AS '6FI1.PV',
[tb6FI34%PV].[Val] AS '6FI34.PV'
FROM [tbIndDate]
LEFT JOIN [tb6FI1%PV] ON [tbIndDate].[TStamp]=[tb6FI1%PV].[TStamp]
LEFT JOIN [tb6FI34%PV] ON [tbIndDate].[TStamp]=[tb6FI34%PV].[TStamp];
I am using SQL Server 2005.
I have a site that people can vote on awesome motorcycles. Each time a user votes, there is one for the first bike and one vote against the second bike. Two votes are stored in the database. The vote table looks like this:
VoteID VoteDate BikeID Vote
1 2012-01-12 123 1
2 2012-01-12 125 0
3 2012-01-12 126 0
4 2012-01-12 129 1
I want to tally the votes for each bike quite frequently, say each hour. My idea is to store the tally as a percentage of contest won versus lost on the bike table as an attribute of the bike. So, if a bike won 10 contests and lost 20 contest, they would have a score (tally) of 33. I would tally up daily, weekly, and monthly scores.
BikeID BikeName DailyTally WeeklyTally MonthlyTally
1 Big Dog 5 10 50
2 Big Cat 3 15 40
3 Small Dog 9 8 0
4 Fish Face 19 21 0
Right now, there are about 500 votes per day being cast. We anticipate 2500 - 5000 per day in the next month or so.
What is the best way to tally the data and what is the best way to store it? Should the tallies be on their own table? Should a trigger be used to run a new tally each time a bike is voted on? Should a stored procedure be run hourly to get all tallies?
Any ideas would be very helpful!
Store your VoteDate as a datetime value instead of just date.
For your tallies, you can just make that a view and calculate it on the fly. This should be very simple to do using GROUP BY and DATEPART functions. If you need exact code for how to do this, please open a new question.
For that low volume of rows it doesn't make any sense to store aggregations in a table when you can just calculate them whenever you want to see them and get accurate and immediate results that are up-to-date.
I agree with #JNK try a view or just a normal stored proc to calculate the outputs on the fly. If you find it becomes too slow as your data grows I would investigate other routes then (like caching the data in another table etc). Probably worth keeping it simple to start with; you can always resuse the logic from the SP/VIEW later if you do want to setup a scheduled task.
Edit :
Removed the index view as per #Damien_The_Unbeliever comments its not deterministic and i'm stupid :)
Okay, I need help. I'm usually pretty good at SQL queries but this one baffles me. By the way, this is not a homework assignment, it's a real situation in an Access database and I've written the requirements below myself.
Here is my table layout. It's in Access 2007 if that matters; I'm writing the query using SQL.
Id (primary key)
PersonID (foreign key)
EventDate
NumberOfCredits
SuperCredits (boolean)
There are events that people go to. They can earn normal credits, or super credits, or both at one event. The SuperCredits column is true if the row represents a number of super credits earned at the event, or false if it represents normal credits.
So for example, if there is an event which person 174 attends, and they earn 3 normal credits and 1 super credit at the event, the following two rows would be added to the table:
ID PersonID EventDate NumberOfCredits SuperCredits
1 174 1/1/2010 3 false
2 174 1/1/2010 1 true
It is also possible that the person could have done two separate things at the event, so there might be more than two columns for one event, and it might look like this:
ID PersonID EventDate NumberOfCredits SuperCredits
1 174 1/1/2010 1 false
2 174 1/1/2010 2 false
3 174 1/1/2010 1 true
Now we want to print out a report. Here will be the columns of the report:
PersonID
LastEventDate
NumberOfNormalCredits
NumberOfSuperCredits
The report will have one row per person. The row will show the latest event that the person attended, and the normal and super credits that the person earned at that event.
What I am asking of you is to write, or help me write, the SQL query to SELECT the data and GROUP BY and SUM() and whatnot. Or, let me know if this is for some reason not possible, and how to organize my data to make it possible.
This is extremely confusing and I understand if you do not take the time to puzzle through it. I've tried to simplify it as much as possible, but definitely ask any questions if you give it a shot and need clarification. I'll be trying to figure it out but I'm having a real hard time with it, this is grouping beyond my experience...
Create a query/view of the following (say its called PersonLastEvents):
select PersonId, max(EventDate) as LastEventDate
from Events
group by PersonId
Then you can get the data you need with the following. I'm not fully familiar with Access, so you may need to modify some of the syntax, but hopefully this will give you an approach.
select l.PersonId, l.LastEventDate,
sum(case when e.SuperCredits = 'false' then e.NumberOfCredits end)
as NumberOfNormalCredits
sum(case when e.SuperCredits = 'true' then e.NumberOfCredits end)
as NumberOfSuperCredits
from PersonLastEvents l
join Events e on l.PersonId = e.PersonId and l.LastEventDate = l.EventDate
group by l.PersonId, l.LastEventDate
As an aside, it may be easier to change your table to have two number columns (NormalCredits, SuperCredits) as it allows you to simply sum() the columns as required.