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in many RDBMS there are tow ways to write join statement
1-by using equal operator (=) for primary and foreign keys
2-by using an statement build on SQL that is(join on f1=f2)
my quistion is:
is there any deference between tow methods(i mean in performance only(execution plan)?
and previusly thanks for all
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An = is used in the select, an = is also used in the join statement. The join is used to join two tables, the where clause is used to filter the results. If you put it all in the where clause, I suspect it's going to perform worse, as it will build a list of all the data in all the tables, then filter it for the entire where statement.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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Using SQL Server 2005.
What is the best datatype for a monetary value? Eg £34.45 or thirty four pounders and fourty five pence.
Float?
Double?
Int?
Or other????
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Decimal(16,2) where you should replace the "2" with the number of decimal places to use (many prices need to be stored to 6 decimal places, but if you just need pence then 2 places would do. The "16" is the number of digits to record (so in my example you would have up to 14 digits in front of the decimal point.
Float and double are not precise, so you often get 3.99999999987 instead of 4.00.
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More numbers = more precise riiiiiiiiiiiiight???? :->
Cleako
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Hi,
I want to make a simple document system.
But i don't know what to do store my files in SQL or store a little XML in the table
1. Store the whole file in the DB (like a BLOB or something like this)
including other columns (title, little explanation, author, date,...)
2 Store a little XML file in the DB with a filepath to the file but in XML all the metatags like the
columns in point 1.
I don't know which is the best choise!!!
Ok, i shall restrict the files to a max of 10Mb.
for versioning - The XML solution is maybe better?
Searching goes faster in ...?
performance...? size of DB I think it will grow rapidly?
Security easiest in which solution?
Can anyone put me in the right direction!!!
Please what do you think
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You might want to consider using Microsoft SharePoint. It does all of this and is free.
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Hi,
Doesn't anyone knows how can I copy a CLR Stored Procedure from one database to another.
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I haven't done it before but have you tried this:
Source Server:
1) Right-click assembly (under programmability - assemblies - {assembly}) SCRIPT Assembly as.... - CREATE TO - New query window
2) Right-click stored proc (programmability - stored procedures - {stored proc}) SCRIPT stored procedure as... - CREATE To - New query window
Target Server:
Change connection for #1 and execute against target, then change connection for #2 and execute against target
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Thanks, Mark  !
It works!
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hi!
I've to run a .net App developed in VS2003 to run on aNT4.0 Client.But lot ofapplications on the NT system are using MDAC2.1.
If I install MDAC2.81 on NT, will there be any threat to my exisiting applications.If so can I install MDAC2.81 without conflicting the earlier version MDAC2.1,can someone help me with this?Its Urgent for me
Thanks in advance
Anji
anji
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Hi,
We are Beginners in Sql and oracle. We are working with Java as front end and Oracle8i as the back end. We have to retrieve the results of those queries executed with dual table in oracle and display them in our front end.
We have connected Java with oracle using JDBC. Our connection is working properly. So our problem is only regarding retrieving. Pls help us with code.
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You have read the bit beside the image of the green alien at the top of this page haven't you? I would take a look at that if I were you, and then ask yourself if this is really the right site to ask this question on.
the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer
Deja View - the feeling that you've seen this post before.
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I used to lead an oracle team (I've now seen the light an am back to using SQL-Server ). My developers found Expert Oracle JDBC Performance Applications[^] really useful for JDBC.
However, most of the work was done using Hibernate instead of JDBC. This allowed them to work at a much higher level of abstraction from the database.
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I have three tables family,productfamily(cross reference between product table and family),familycontent(cross reference between family and content), productcontent(cross reference between product and content)
Family table itself is the master of its own. Some families may be sub families of other family. For every family we need to go to familycontent table and see if record exists. If it does not, it should check its subfamilies and also productfamily and see whether any of the child family has got contents in familycontent or any of the products under that contains record in productcontent table. Child families can be upto 'n' level. We need to loop through like this until we loop through the entire hierarchy or until we get a record in either of the familycontent or productcontent table. Is there an easy way to get in SQL Query or we need to use Cursor and recursive function/Stored procedure. Please advice
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Hi,
I am adding a file to a filegroup on a remote machine, and i don't know the direcotry structure of that machine, how can i provide the path for FILENAME param, since FILENAME params requires complete valid path of a physical file in that system.
ALTER DATABASE TESTDB ADD FILE (NAME = N'TESTFILE', FILENAME = N'physicalfilepath.ndf') TO FILEGROUP TESTFILEGROUP
Warm Regards,
Mushq
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If this is going in the same place as the other files in the group you can find out the existing path with SELECT * FROM sysfiles
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Hi all, i have a few quetion to discover, bee so pleasant to explain me how i can do:
1)
I have combobox and data source for one
<br />
this.comboBox1.DataSource = this.authorsBindingSource;<br />
Now I need to add to combobox an row, what not exist in bindingSource (supoose I want do display in combobox an additional row "not defined")
How I can do this????
---------------------------------------------------------------
2)
How I can to mark a rows in dataTable, so that ones not will be stored in database then this dataTable updated.
I mean:
<br />
<br />
DataRow dr1 = myDataTable.NewRow();<br />
<br />
..<br />
<br />
<br />
myDataTable.Rows.Add(dr1);<br />
<br />
<br />
DataRow dr2 = myDataTable.NewRow();<br />
<br />
..<br />
<br />
<br />
myDataTable.Rows.Add(dr2);<br />
<br />
this.myDataTableAdapter.Update(myDataTable);<br />
How I can do this.
-----------------------------------------------------------------------------------
3) How I can explore what column (DataColumn type) have default value???
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Morning guys (GMT guys that is)
I am having issues deciding on exactly how to perform a very large chunk of programming. I need to query the database im working with to build up a table of statistics from the various tables within the database. Each product must be selected and then 10 individual statistics, many involving averaging and percentaging, must be generated per product. Therefore there will be 10 queries x the number of products found run each time.
The thing im not really sure about is quite where to put the programming itself. Should it be in a seperately coded class as part of my ASP.net project or should it be completely coded in sql in a stored procedure.
I need a speed, ease of achievability and also a managability perspective on any proposed technique. Thanks
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Hi Sam
I would use a stored procedure based on the following SQL:
SELECT ProductCode,
(SELECT ###Statistics sub-select### FROM MyTable1 A
WHERE A.ProductCode = Product.ProductCode) AS Statistic1,
(SELECT ###Statistics sub-select### FROM MyTable2 A
WHERE A.ProductCode = Product.ProductCode) AS Statistic2,
###etc
FROM Product
ORDER By ProductCode You need to replace the "###" bits with SQL that matches your statistical requirements.
Hope that helps.
Andy
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hi everybody!
I am a beginner in PL/SQL.I am currently doing a project based on PL/SQL with java as front end.
Basically I am developing an editor for PL/SQL.
I want to know how could we retrieve the resulting statements of PL/SQL program that is executed in Oracle.
for eg:
how to retrieve the result of a query say,
'Query completed successfully' which is displayed in Oracle editor to the front end form.
Does anybody know how to proceed with this?
Kindly bear with me as am new to Code Project.
If anybody of you know the answer, can you be so kind and
respond me!
Regards,
Shalini
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Hi everybody,
I wrote a script in Installshield that changes the MaxLocksPerFile value in
Registry for Jet 3.x and Jet 4.0
While installing the application through Installshield, the custom value for
MaxLocksPerFile is being overwritten to 9500 in Registry for Jet
4.0(HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Jet 4.0) but not
for Jet 3.x(HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Jet 3.x).
The value is being overwritten to 9500 before the control reaches at the
script code.
I am wondering from where this 9500 value is being retrieved and set in
Registry.
Is there some file where these default values are mentioned.
If so then why 9500 value is not being set for Jet 3.x and is being set only
for Jet 4.0.
i am using MS Office 2002. Drivers for ODBC MS Access is above 4.0
and Installshield Version is 5.5.
Please help me to resolve this Issue.
-Regards
Harpreet
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