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Never stop asking questions, just make sure you have thought about the questions you are asking. ALWAYS do some research before dumping it into the forum, especially as you are learning. Almost every question you can come up with will have already been asked many times.
Never underestimate the power of human stupidity
RAH
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Hi again
I have made this schema,is this correct(its my first question)
LogIn table
user_name(primary key) password AuthorID(Foreign key) PublisherID(foreign key)
Publishers table
publisherID(primark key) publisher name phone address (and other fields)
Authors table
AuthorID(primary key) Author name phone address publisherID(Foreign key) (and other fields)
Books Table
BookID(primary key) Book name Year Title (and other fields)
and its my second question I thought to make this table for AuthorBook
AuthorBook table
AuthorBookID(primary key) AuthorID(Foreign key) BookID(Foreign key)
Do I need to Foreign key in Authors table or Book tables?
Thanks
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Don't you think an author might publish different books via different publishers?
messages wrote: Do I need to Foreign key in Authors table or Book tables?
You should always use foreign keys in your tables whenever possible. It lowers the risk of corruption.
BTW, you're having a good naming standard for your fields.
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Thank you for your help so my code is good and I need only to insert foreign key to Authors,right?
Thanks again
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It's ok so far, but you're not ready yet.
To clarify what I mentioned in my previous message, is that I doubt that it's correct that the Authors table is having the field PublisherID in it. As an author might choose to publish different books at different publishers.
I would argue that you need another link table, the BookPublisher table.
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FYI.
In the world of libraries it is important to note that a book might be bought multiple times even for the same library.
Like when Stephen King comes out with a new book. The library might buy 2 hardback copies that will be kept for a long time, and then they might buy later a set of paperbacks that won't last as long.
So, not only do you need a books table but you also need a table called 'items' that track the existence of the multiple copies of the same book.
When someone checks out a book they are actually checking out an 'item'.
Is this for a real library with patrons or is it a personal library, or an exercise?
In my personal library I have some books where I have more than one copy. Each instance has a different reason for being bought twice but that isn't important.
If you are doing this for a real public library you might have more things to add. You might also have to study the world of MARC records.
http://en.wikipedia.org/wiki/MARC_standards[^]
_____________________________
A logician deducts the truth.
A detective inducts the truth.
A journalist abducts the truth.
Give a man a mug, he drinks for a day. Teach a man to mug...
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I am having such a hard time writing a SQL query. Can someone please look over this query and see where am I going wrong?
I will be using the XML elements to describe the table even though I am using SQL Server 2008 R2..
<vPSR>
<ProjectID/>
<ReportMonth Comment="2 digit Month. (MM)" />
<ReportYear Comment="4 digit Year. (YYYY)" />
</vPSR>
Here is an example of the data that is listed.
ProjectID ReportMonth ReportYear
1000700 05 2008
1000700 06 2008
1000700 07 2008
1000700 12 2008
1000700 01 2009 <-- I want the query to find this! Even though the Month is not the max value, but the Year is the Max value.
Here is what I have so far. Where am I going wrong?
SELECT vPSR.ProjectID, vPSR.ReportMonth, vPSR.ReportYear
FROM vPSR
WHERE vPSR.ReportMonth =
(SELECT MAX(ReportMonth)
FROM vPSR AS f
WHERE f.ProjectID = ProjectID
AND ReportYear =
(SELECT MAX(ReportYear)
FROM vPSR AS k
WHERE k.ProjectID = vPSR.ProjectID))
ORDER BY vPSR.ProjectID ASC
I got the idea on how to write the above query here.[^] I don't understand it that well.
If you need me to clarify anything please do not hesitate to ask.
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I'm thinking that ReportMonth and ReportYear should instead have been a ReportDate with some sort of Date datatype. Since they're not, concatenating the two columns seems to work:
SELECT ProjectID, reportMonth, reportYear
FROM test
WHERE (reportYear + reportMonth =
(SELECT MAX(reportYear + reportMonth) AS Expr1
FROM test AS b
WHERE (ProjectID = ProjectID)))
Scott
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You could try something like
SELECT vPSR.ProjectID, vPSR.ReportMonth, vPSR.ReportYear
FROM vPSR
INNER JOIN (
SELECT ProjectID, MAX(reportYear + reportMonth) AS Expr1
FROM vPSR
GROUP by ProjectID
) AS v2
ON vPSR.ProjectID = v2.ProjectID
AND (vPSR.ReportYear + vPSR.ReportMonth) = v2.Expr1
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I whole heartedly agree about concatenating the ReportMonth + ReportYear columns together. That was another idea that I have been thinking about.
Thanks!
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Can you extend the sample population to give some more detail?
In the meantime, here's something to play with;
SET NOCOUNT ON;
BEGIN TRANSACTION
IF OBJECT_ID('vPSR') IS NOT NULL DROP TABLE vPSR
SELECT 1000700 as ProjectID,
05 as ReportMonth,
2008 as ReportYear
INTO vPSR
UNION SELECT 1000700, 06, 2008
UNION SELECT 1000700, 07, 2008
UNION SELECT 1000700, 12, 2008
UNION SELECT 1000700, 01, 2009
UNION SELECT 1000701, 11, 2011
UNION SELECT 1000701, 12, 2009
SELECT TOP 1 *
FROM vPSR
WHERE ReportYear = (SELECT MAX(ReportYear) FROM vPSR)
ORDER BY ReportMonth DESC
SELECT TOP 1 *
FROM vPSR
ORDER BY ReportYear DESC, ReportMonth DESC
SELECT DISTINCT ProjectID
, (SELECT MAX(ReportYear) FROM vPSR WHERE ProjectID = A.ProjectID)
, (SELECT TOP 1 ReportMonth FROM vPSR WHERE ProjectID = A.ProjectID AND ReportYear = (
SELECT MAX(ReportYear) FROM vPSR WHERE ProjectID = A.ProjectID) ORDER BY ReportMonth DESC)
FROM vPSR A
ROLLBACK
My results;
ProjectID ReportMonth ReportYear
----------- ----------- -----------
1000701 11 2011
ProjectID ReportMonth ReportYear
----------- ----------- -----------
1000701 11 2011
ProjectID
----------- ----------- -----------
1000700 2009 1
1000701 2011 11
Bastard Programmer from Hell 
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Quote: Can you extend the sample population to give some more detail?
Yes, I sure can!
What I need to do is organize a table that has multiple listings of a Project ID and return only 1 of the latest (date related) per Project ID. Therefore, here is a sample listing of the data that I need to organize.
ProjectID ReportYear ReportMonth
----------- ----------- -----------
100005000 2008 5
100005000 2008 6
100005000 2008 7
100006600 2008 8
100006600 2008 9
100006600 2008 10
100006600 2008 11
100006600 2008 12
100006600 2009 1
100006800 2008 8
100006800 2008 9
100006800 2009 1
100006800 2009 2
100006800 2009 3
100006800 2009 4
Note: I trimmed down the data so as not to overwhelm this post, but still relay the idea of what I am dealing with.
There is also one more thing I would like to ask your advice. It's about an idea that I have been thinking about. What if I were to instead create a temporary table and create an extra column with "ReportDate" and add the Year and Month together. (I know someone has also mentioned this in a reply to my first post). So, it would be something to the affect of (ReportYear * 100) + ReportMonth. Then I could write a query with the above sample data and return back per ProjectID the latests info. What do you think? Further, can you please link me to a "How-To" article on creating temp tables in SQL Server 2008?
One last question about something that I don't understand and have been searching MSDN and Google to no avail. It's this whole alias thing ("AS" keyword). You can place use this in for the column name and/or the table name. But I don't understand how I can do something to affect of ...
SELECT MAX(ReportYear) FROM vPSR AS f WHERE f.ProjectID = vPSR.ProjectID
I don't understand how f.ProjectID can equal vPSR.ProjectID. This seems very circular to me. This is a technique that I don't use often. If you have any info/advice about this way of writing a query can you link me?
Thanks!
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Clark Kent123 wrote: What I need to do is organize a table that has multiple listings of a Project ID and return only 1 of the latest (date related) per Project ID.
The last sql-statement is almost a literal translation of that request; it fetches a unique list of all projectid's (distinct), and then the maximum year for that projectid. Lastly, it fetches the maximum month for that projectid in the max(year).
SET NOCOUNT ON;
BEGIN TRANSACTION
SELECT 100005000 as ProjectID,
2008 as ReportYear,
05 as ReportMonth
INTO vPSR
UNION SELECT 100005000, 2008, 6
UNION SELECT 100005000, 2008, 7
UNION SELECT 100006600, 2008, 8
UNION SELECT 100006600, 2008, 9
UNION SELECT 100006600, 2008, 10
UNION SELECT 100006600, 2008, 11
UNION SELECT 100006600, 2008, 12
UNION SELECT 100006600, 2009, 1
UNION SELECT 100006800, 2008, 8
UNION SELECT 100006800, 2008, 9
UNION SELECT 100006800, 2009, 1
UNION SELECT 100006800, 2009, 2
UNION SELECT 100006800, 2009, 3
UNION SELECT 100006800, 2009, 4
SELECT DISTINCT ProjectID
, (SELECT MAX(ReportYear) FROM vPSR WHERE ProjectID = A.ProjectID) AS MaxReportYear
, (SELECT TOP 1 ReportMonth FROM vPSR WHERE ProjectID = A.ProjectID AND ReportYear = (
SELECT MAX(ReportYear) FROM vPSR WHERE ProjectID = A.ProjectID) ORDER BY ReportMonth DESC)
AS MaxReportMonth
FROM vPSR AS A
ROLLBACK
ProjectID MaxReportYear MaxReportMonth
100005000 2008 7
100006600 2009 1
100006800 2009 4
Clark Kent123 wrote: What if I were to instead create a temporary table and create an extra column with "ReportDate" and add the Year and Month together. (I know someone has also mentioned this in a reply to my first post). So, it would be something to the affect of (ReportYear * 100) + ReportMonth. Then I could write a query with the above sample data and return back per ProjectID the latests info. What do you think? Further, can you please link me to a "How-To" article on creating temp tables in SQL Server 2008?
There's two ways of declaring a temp table in Sql Server, and there's a CodeProject article[^] that compares them 
Clark Kent123 wrote: I don't understand how f.ProjectID can equal vPSR.ProjectID. This seems very circular to me. This is a technique that I don't use often. If you have any info/advice about this way of writing a query can you link me?
It's a subquery; we introduced the table under a new name, being called "F" "A". Let's simply walk through the query; it first fetches all projectid's from vPSR (which we'll call "table A"). For each record, it tries to display the values in the columns of our select-statement, and our second column is a new query. So, it executes that query.
SELECT MAX(ReportYear) FROM vPSR WHERE ProjectID = A.ProjectID
Now, the table in the query was called "A", so for the first record this subquery would read as below;
SELECT MAX(ReportYear) FROM vPSR WHERE ProjectID = 100005000
Then it returns that value instead that results from that query.
The technique is called "correlation", which sounds fancy, but really merely means that you're referring to a field in the outer query from a subquery. You could substitute the "A" in the example with any string you'd like, and Sql Server will treat it as if it were a new table with the same contents under that name.
Bastard Programmer from Hell
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Wow. You have given me much food for thought. Let me digest all this info. If I have any questions I will bug you again! 
I really do appreciate the help. 
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My pleasure, and you're welcome
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I have spent weeks on a SSRS reporting services 2005 report. I set up a subscription to email automatically. Managers with Outlook 2003 can view the report perfectly. Managers with Outlook 2007 get a truncated and garbled email report from Report Manager. Has anyone come across this before???
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Well I'm guessing that the emailed report is identical, so it must be something changed in the client config or the Exchange server.
Have you been through the various Outlook options relating to encoding?
Also it seems like your mid upgrade too, maybe somebody changed something on the Exchange side?
As a test could you send an report to a completely different address (i.e. gmail).
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When migrating from oracle 10g to 11g, I've a stored procedure with a syntax like:
select * from table1
union
select t,y from
(select * from table2)aliasQuery
where (select max(t)from (select t from table 3 where table3. t=aliasQuery.t)
query works well with 10g but 11g returns error that aliasQuery not defined
may be this syntax no longer supported in 11g or here is some database missing configurations
Thanks
Dad
modified 15 Feb '12.
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Could you check that you wrote the query correctly. It seems incorrect.
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Logically speaking
select ..
from ( select * from table ) aliasquery
where ...
is no different from
select ..
from table aliasquery
where ...
Please verify the SQL you have posted.
Chris Meech
I am Canadian. [heard in a local bar]
In theory there is no difference between theory and practice. In practice there is. [Yogi Berra]
posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]
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Oracle is so great! They even fix bugs which caused such queries to be possible.
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I know, I had to think very carefully about that one. This query used to work but only because it was a bug (in other words you thought it was good, but in fact we knew it was bad), so we fixed the bug and now your query doesn't work anymore (which you may think is bad, but really it's not, because we know it's good).
If I follow the argument correctly, it has something to do with ANSI standards: you should not be able to do this in ANSI-standard SQL. So in order for Oracle to be ANSI-standard, they had to stop you from doing this. I think that's the reason.
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Hi everyone,
I have a question about databases.are these correct?
A database is a structured collection of data.
A DBMS is a software package,it creates and management databases,sql server,access and oracle are examples of DBMS.
Is RDBMS a subroutine of DBMS or no?
I want to know what are Flat ,Hierarchical,Relational,Object-oriented databases? they are relative to DBMS or database?
Thanks
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