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  • What is wrong with my SQL syntax for an UPDATE with a JOIN?

    - by Phil H
    I have two tables, related by a common key. So TableA has key AID and value Name and TableB has keys AID, BID and values Name, Value: AID Name 74 Alpha AID BID Name Value 74 4 Beta Brilliance I would like to update the TableB Value here from Brilliance to Barmy, using just the Name fields. I thought I could do it via an UPDATE containing a JOIN, but Access (I know...) is complaining with 'Syntax error (missing operator) in query expression ' and then everything from 'Barmy' here: UPDATE tB SET tB.BValue='Barmy' FROM TableB tB INNER JOIN TableA tA ON tB.AID=tA.AID WHERE tB.Name='Beta' AND tA.Name='Alpha'; What is my heinous crime? Or is it just Access not conforming?

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  • where can I get these kind of exercises to solve?

    - by flash
    Recently I did a Java programming exercise successfully which was sent by a recruiting firm, The problem statement goes like this 'There are two text files FI(records abt files and directory information) and FS(containing blocks of data) which represent a file Index and file System respectively and I was supposed to write a static read method in a class which will read the file from the FS depending upon the path string provided using FI' My question is where can I get these kind of exercises to solve, the complexity should be above average to tough.

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  • Limit user in sql plus to a single record in a table.

    - by BFK
    I have one employee table...this table has 5 coloumns (empname, empgsm, empsal, empaddr, empdep)...it has 10 records. i've created 10 users equivelent to the empnames coloumn in the table. When a user logs in with his empname aka username & password, he will be able to see only his record from the table. eg.Smith is an employee, a user called smith was created. when this user is in session, and types "Select * from Employee_table" he only gets the record that belongs to him, where empname is smith. how do i do this using privileges? thanks in advance

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  • Is it possible to write a SQL query to return specific rows, but then join some columns of those row

    - by Rob
    I'm having trouble wrapping my head around how to write this query. A hypothetical problem that is that same as the one I'm trying to solve: Say I have a table of apples. Each apple has numerous attributes, such as color_id, variety_id and the orchard_id they were picked from. The color_id, variety_id, and orchard_id all refer to their respective tables: colors, varieties, and orchards. Now, say I need to query for all apples that have color_id = '3', which refers to yellow in the colors table. I want to somehow obtain this yellow value from the query. Make sense? Here's what I was trying: SELECT * FROM apples, colors.id WHERE color_id = '3' LEFT JOIN colors ON apples.color_id = colors.id

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  • Is a full list returned first and then filtered when using linq to sql to filter data from a databas

    - by RJ
    This is probably a very simple question that I am working through in an MVC project. Here's an example of what I am talking about. I have an rdml file linked to a database with a table called Users that has 500,000 rows. But I only want to find the Users who were entered on 5/7/2010. So let's say I do this in my UserRepository: from u in db.GetUsers() where u.CreatedDate = "5/7/2010" select u (doing this from memory so don't kill me if my syntax is a little off, it's the concept I am looking for) Does this statement first return all 500,000 rows and then filter it or does it only bring back the filtered list?

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  • Oracle SQL: Multiple Subqueries Unioned Without Running Original Query Multiple Times.

    - by Bob
    So I've got a very large database, and need to work on a subset ~1% of the data to dump into an excel spreadsheet to make a graph. Ideally, I could select out the subset of data and then run multiple select queries on that, which are then UNION'ed together. Is this even possible? I can't seem to find anyone else trying to do this and would improve the performance of my current query quite a bit. Right now I have something like this: SELECT ( SELECT ( SELECT( long list of requirements ) UNION SELECT( slightly different long list of requirements ) ) ) and it would be nice if i could group the commonalities of the two long requirements and have simple differences between the two select statements being unioned.

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  • How to check if the sum of some records equals the difference between two other records in t-sql?

    - by Dan Appleyard
    I have a view that contains bank account activity. ACCOUNT BALANCE_ROW AMOUNT SORT_ORDER 111 1 0.00 1 111 0 10.00 2 111 0 -2.50 3 111 1 7.50 4 222 1 100.00 5 222 0 25.00 6 222 1 125.00 7 ACCOUNT = account number BALANCE_ROW = either starting or ending balance would be 1, otherwise 0 AMOUNT = the amount SORT_ORDER = simple order to return the records in the order of start balance, activity, and end balance I need to figure out a way to see if the sum of the non balance_row rows equal the difference between the ending balance and the starting balance. The result for each account (1 for yes, 0 for no) would be simply added to the resulting result set. Example: Account 111 had a starting balance of 0.00. There were two account activity records of 10.00 and -2.5. That resulted in the ending balance of 7.50. I've been playing around with temp tables, but I was not sure if there is a more efficient way of accomplishing this. Thanks for any input you may have!

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  • What is the performance of "Merge" clause in sql server 2008?

    - by ziang
    Hi, Merge can performs insert, update, or delete operations on a target table based on the results of a join with a source table. For example, you can synchronize two tables by inserting, updating, or deleting rows in one table based on differences found in the other table. Is anyone familiar with the performance to use "Merge" versus the traditional logic to check existence and decide the update or insert then? Thanks!

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  • How optimize queries with fully qualified names in t-sql?

    - by tomaszs
    Whe I call: select * from Database.dbo.Table where NAME = 'cat' It takes: 200 ms And when I change database to Database in Management Studio and call it without fully qualified name it's much faster: select * from Table where NAME = 'cat' It takes: 17 ms Is there any way to make fully qualified queries faster without changing database?

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  • How to find the closest descendants (that matches a selector) with jQuery?

    - by powerboy
    We can use closest(selector) to find the first ancestor element that matches the selector. It travels up the DOM tree until it finds a match for the selector. But what if I want to travels down the DOM tree until it finds a match for the selector? Is there any jQuery function for doing this? Or do I need to implement this using breadth-first search? Give an example. For the DOM tree below, <div id="main"> <div> <ul><!-- I want to match this ul --> <li> <ul><!-- but not this ul --> </ul> </li> </ul> <ul><!-- and match this ul --> </ul> </div> </div> how to do something like $('#main').closestDescendants('ul')?

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  • Why did the following linq to sql query generate a subquery?

    - by Xaisoft
    I did the following query: var list = from book in books where book.price > 50 select book; list = list.Take(50); I would expect the above to generate something like: SELECT top 50 id, title, price, author FROM Books WHERE price > 50 but it generates: SELECT [Limit1].[C1] as [C1] [Limit1].[id] as [Id], [Limit1].[title] as [title], [Limit1].[price] as [price], [Limit1].[author] FROM (SELECT TOP (50) [Extent1].[id] as as [Id], [Extent1].[title] as [title], [Extent1].[price] as [price], [Extent1].[author] as [author] FROM Books as [Extent1] WHERE [Extent1].[price] > 50 ) AS [Limit1] Why does the above linq query generate a subquery and where does the C1 come from?

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  • What does an object file contain

    - by benjamin button
    HI everyone, during the various stages of compilation in C or C++, i know that an object file gets generated. i.e., any_name.o file. what does thos .o file contain actually. i cant open it since its a binary file. Could anybody please help me? are the contents of the object file mainly Dependant on the compiler which we use on unix?

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  • How should I do this (business logic) in Sql Server? A constraint?

    - by Pure.Krome
    Hi folks, I wish to add some type of business logic constraint to a table, but not sure how / where. I have a table with the following fields. ID INTEGER IDENTITY HubId INTEGER CategoryId INTEGER IsFeatured BIT Foo NVARCHAR(200) etc. So what i wish is that you can only have one featured thingy, per articleId + hubId. eg. 1, 1, 1, 1, 'blah' -- Ok. 2, 1, 2, 1, 'more blah' -- Also Ok 3, 1, 1, 1, 'aaa' -- constraint error 4, 1, 1, 0, 'asdasdad' -- Ok. 5, 1, 1, 0, 'bbbb' -- Ok. etc. so the third row to be inserterd would fail because that hub AND category already have a featured thingy. Is this possible?

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  • How can I get a list of modified records from a SQL Server database?

    - by Pixelfish
    I am currently in the process of revamping my company's management system to run a little more lean in terms of network traffic. Right now I'm trying to figure out an effective way to query only the records that have been modified (by any user) since the last time I asked. When the application starts it loads the job information and caches it locally like the following: SELECT * FROM jobs. I am writing out the date/time a record was modified ala UPDATE jobs SET Widgets=@Widgets, LastModified=GetDate() WHERE JobID=@JobID. When any user requests the list of jobs I query all records that have been modified since the last time I requested the list like the following: SELECT * FROM jobs WHERE LastModified>=@LastRequested and store the date/time of the request to pass in as @LastRequest when the user asks again. In theory this will return only the records that have been modified since the last request. The issue I'm running into is when the user's date/time is not quite in sync with the server's date/time and also of server load when querying an un-indexed date/time column. Is there a more effective system then querying date/time information?

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  • SQL: Is it quicker to insert sorted data into a table?

    - by AngryWhenHungry
    A table in Sybase has a unique varchar(32) column, and a few other columns. It is indexed on this column too. At regular intervals, I need to truncate it, and repopulate it with fresh data from other tables. insert into MyTable select list_of_columns from OtherTable where some_simple_conditions order by MyUniqueId If we are dealing with a few thousand rows, would it help speed up the insert if we have the order by clause for the select? If so, would this gain in time compensate for the extra time needed to order the select query? I could try this out, but currently my data set is small and the results don't say much.

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  • Can you use the same Enum in multiple entities in Linq-to-SQL?

    - by Mark
    In my persistence layer, I've declared a load of Enums to represent tables containing reference data (i.e. data never changes). In Linq2SQL, I am able to set the type of an entity property to an enum type and all is well, but as soon as I set a second entity's property to use the same enum type, the Code Generator (MSLinqToSQLGenerator) start generating an empty code file. I assume that MSLinqToSQLGenerator is quietly crashing. The question is why, and are there any work-arounds? Anyone else experienced this problem?

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  • Java Inheritance Concept Understanding

    - by Nirmal
    Hello All.... I am just refreshing the oops features of the java. So, I have a little confusion regarding inheritance concept. For that I have a following sample code : class Super{ int index = 5; public void printVal(){ System.out.println("Super"); } } class Sub extends Super{ int index = 2; public void printVal(){ System.out.println("Sub"); } } public class Runner { public static void main(String args[]){ Super sup = new Sub(); System.out.println(sup.index+","); sup.printVal(); } } Now above code is giving me output as : 5,Sub. Here, we are overriding printVal() method, so that is understandable that it is accessing child class method only. But I could not understand why it's accessing the value of x from Super class... Thanks in advance....

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