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• introduce a join to this query, possible?

  - by Iain Urquhart

  I'm trying to introduce a join to this query: SELECT `n`.*, round((`n`.`rgt` - `n`.`lft` - 1) / 2, 0) AS childs, count(*) - 1 + (`n`.`lft` > 1) + 1 AS level, ((min(`p`.`rgt`) - `n`.`rgt` - (`n`.`lft` > 1)) / 2) > 0 AS lower, (((`n`.`lft` - max(`p`.`lft`) > 1))) AS upper FROM `exp_node_tree_6` `n`, `exp_node_tree_6` `p`, `exp_node_tree_6` WHERE `n`.`lft` BETWEEN `p`.`lft` AND `p`.`rgt` AND ( `p`.`node_id` != `n`.`node_id` OR `n`.`lft` = 1 ) GROUP BY `n`.`node_id` ORDER BY `n`.`lft` by adding LEFT JOIN `exp_channel_titles` ON (`n`.`entry_id`=`exp_channel_titles`.`entry_id`) after the FROM statement... But when I introduce it, it fails with "Unknown column 'n.entry_id' in 'on clause'" Is it even possible to add a join to this query? Can anybody help, thanks!

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• When calling CRUD check if "parent" exists with read or join?

  - by Trick

  All my entities can not be deleted - only deactivated, so they don't appear in any read methods (SELECT ... WHERE active=TRUE). Now I have some 1:M tables on this entities on which all CRUD operations can be executed. What is more efficient or has better performance? My first solution: To add to all CRUD operations: UPDATE ... JOIN entity e ... WHERE e.active=TRUE My second solution: Before all CRUD operations check if entity is active: if (getEntity(someId) != null) { //do some CRUD } In getEntity there's just SELECT * FROM entity WHERE id=? AND active=TRUE. Or any other solution, recommendation,...?

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• Slow query with unexpected scan

  - by zerkms

  Hello I have this query: SELECT * FROM SAMPLE SAMPLE INNER JOIN TEST TEST ON SAMPLE.SAMPLE_NUMBER = TEST.SAMPLE_NUMBER INNER JOIN RESULT RESULT ON TEST.TEST_NUMBER = RESULT . TEST_NUMBER WHERE SAMPLED_DATE BETWEEN '2010-03-17 09:00' AND '2010-03-17 12:00' the biggest table here is RESULT, contains 11.1M records. The left 2 tables about 1M. this query works slowly (more than 10 minutes) and returns about 800 records. executing plan shows clustered index scan over all 11M records. RESULT.TEST_NUMBER is a clustered primary key. if I change 2010-03-17 09:00 to 2010-03-17 10:00 - i get about 40 records. it executes for 300ms. and plan shows clustered index seek if i replace * in SELECT clause to RESULT.TEST_NUMBER (covered with index) - then all become fast in first case too. this points to hdd io issues, but doesn't clarifies changing plan. so, any ideas?

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• Help ! How do I get the total number rows from my mssql paging procedure ?

  - by The_AlienCoder

  Ok I have a table in my MSSQL database that stores comments. My desire is to be able to page though the records using [Back],[Next], page numbers & [Last] buttons in my datalist. I figured the most efficient way was to use a stored procedure that only returns a certain number of rows within a partcular range. Here is what I came up with @PageIndex INT, @PageSize INT, @postid int AS SET NOCOUNT ON begin WITH tmp AS ( SELECT comments.*, ROW_NUMBER() OVER (ORDER BY dateposted ASC) AS Row FROM comments WHERE (comments.postid = @postid)) SELECT tmp.* FROM tmp WHERE Row between (@PageIndex - 1) * @PageSize + 1 and @PageIndex*@PageSize end RETURN Now everything works fine and I have been able implement [Next] and [Back] buttons in my datalist pager.Now I need the total number of all comments(not in the cuurent page) so that I can implement my page numbers and the[Last] button on my pager. In other words I want to return the total number of rows in my first select statement i.e WITH tmp AS ( SELECT comments.*, ROW_NUMBER() OVER (ORDER BY dateposted ASC) AS Row FROM comments WHERE (comments.postid = @postid)) set @TotalRows = @@rowcount @@rowcount doesnt work and raises an error.I also cant get count.* to work either. Is there another way to get the total amount of rows or is my approach doomed.

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• Storing datetime in database?

  - by Curtis White

  I'm working on a blog and want to show my posts in eastern time zone. i figured that storing everything UTC would be the proper way. This creates a few challenges though: I have to convert all times from UTC to Eastern. This is not a biggie but adds a lot of code. And the "biggie" is that I use a short-date time to reference the posts by passing in a query, ala blogger. The problem is that there is no way to convert the short date time to the proper UTC date because I'm lacking the posted time info. Hmm, any problem to just storing all dates in eastern time? This would certainly make it easier for the rest of the application but if I needed to change time zones everything would be stored wrong.

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• Change column names of a cube action as they appear in Visual Studio

  - by hermann

  the title pretty much says it all. I have a cube with data in it and I have yet to find a way to change the column names. They appear in a very ugly manner like [cubeName].[$dimension.columnName]. I have tried everything I know and anything I found on the web but nothing seems to be working. What I tried to do in most cases is create an Action in the Actions tab and write some MDX query language in there. No results whatsoever. As if the action is never run. Does anyone know how to do this? I've spent about 3 days trying to figure this out. Thank you.

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• In mysql, is "explain ..." always safe?

  - by tye

  If I allow a group of users to submit "explain $whatever" to mysql (via Perl's DBI using DBD::mysql), is there anything that a user could put into $whatever that would make any database changes, leak non-trivial information, or even cause significant database load? If so, how? I know that via "explain $whatever" one can figure out what tables / columns exist (you have to guess names, though) and roughly how many records are in a table or how many records have a particular value for an indexed field. I don't expect one to be able to get any information about the contents of unindexed fields. DBD::mysql should not allow multiple statements so I don't expect it to be possible to run any query (just explain one query). Even subqueries should not be executed, just explained. But I'm not a mysql expert and there are surely features of mysql that I'm not even aware of. In trying to come up with a query plan, might the optimizer actual execute an expression in order to come up with the value that an indexed field is going to be compared against? explain select * from atable where class = somefunction(...) where atable.class is indexed and not unique and class='unused' would find no records but class='common' would find a million records. Might 'explain' evaluate somefunction(...)? And then could somefunction(...) be written such that it modifies data?

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• Why am I unable to create a trigger using my SqlCommand?

  - by acidzombie24

  The line cmd.ExecuteNonQuery(); cmd.CommandText CREATE TRIGGER subscription_trig_0 ON subscription AFTER INSERT AS UPDATE user_data SET msg_count=msg_count+1 FROM user_data JOIN INSERTED ON user_data.id = INSERTED.recipient; The exception: Incorrect syntax near the keyword 'TRIGGER'. Then using VS 2010, connected to the very same file (a mdf file) I run the query above and I get a success message. WTF!

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• How to retrieve indentity column vaule after insert using LINQ

  - by Hobey

  Could any of you please show me how to complete the following tasks? // Prepare object to be saved // Note that MasterTable has MasterTableId as a Primary Key and it is an indentity column MasterTable masterTable = new MasterTable(); masterTable.Column1 = "Column 1 Value"; masterTable.Column2 = 111; // Instantiate DataContext DataContext myDataContext = new DataContext("<<ConnectionStrin>>"); // Save the record myDataContext.MasterTables.InsertOnSubmit(masterTable); myDataContext.SubmitChanges(); // ?QUESTION? // Now I need to retrieve the value of MasterTableId for the record just inserted above. Kind Regards

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• MSSQL: Primary Key Schema Largely Guid but Sometimes Integer Types...

  - by Code Sherpa

  OK, this may be a silly question but... I have inherited a project and am tasked with going over the primary key relationships. The project largely uses Guids. I say "largely" because there are examples where tables use integral types to reflect enumerations. For example, dbo.MessageFolder has MessageFolderId of type int to reflect public emum MessageFolderTypes { inbox = 1, sent = 2, trash = 3, etc... } This happens a lot. There are tables with primary keys of type int which is unavoidable because of their reliance on enumerations and tables with primary keys of type Guid which reflect the primary key choice on the part of the previous programmer. Should I care that the PK schema is spotty like this? It doesn't feel right but does it really matter? If this could create a problem, how do I get around it (I really can't move all PKs to type int without serious legwork and I have never heard of enumerations that have guid values)? Thanks.

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• Indexes and multi column primary keys

  - by David Jenings

  Went searching and didn't find the answer to this specific noob question. My apologies if I missed it. In a MySQL database I have a table with the following primary key PRIMARY KEY id (invoice, item) In my application I will also frequently be selecting on "item" by itself and less frequently on only "invoice". I'm assuming I would benefit from indexes on these columns. MySQL does not complain when I define the following: INDEX (invoice), INDEX (item), PRIMARY KEY id (invoice, item) But I don't see any evidence (using DESCRIBE -- the only way I know how to look) that separate indexes have been established for these two columns. So the question is, are the columns that make up a primary key automatically indexed individually? Also, is there a better way than DESCRIBE to explore the structure of my table?

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• Loop Stored Procedure in VB.Net (win form)

  - by Mo

  Hello, I am trying to run a for loop for a backup system and inside that i want to run a SP that will loop. Below is the code that does not work for me.. Any ideas please? Dim TotalTables As Integer Dim i As Integer TotalTables = 10 For i = 1 To TotalTables objDL.BackupTables(220, i, 001) ' (This is a method from the DL and the 3 parameters are integars) Next I tried the SP and it works perfectly in SQLServer

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• I got an error when implementing tde in sql2008

  - by mahima

  while using USE mssqltips_tde; CREATE DATABASE ENCRYPTION KEY with ALGORITHM = AES_256 ENCRYPTION BY SERVER CERTIFICATE TDECert GO getting error Msg 156, Level 15, State 1, Line 2 Incorrect syntax near the keyword 'KEY'. Msg 319, Level 15, State 1, Line 3 Incorrect syntax near the keyword 'with'. If this statement is a common table expression or an xmlnamespaces clause, the previous statement must be terminated with a semicolon. please help in resolving the same as i need to implement Encryption on my DB

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• Is a nvarchar(max) less performant than a nvarchar(100) for instance?

  - by Lieven Cardoen

  Is a nvarchar(max) less performant than a nvarchar(100) for instance?

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• Out Parameters in Stored Procedures

  - by mkus

  Hi, Let's think that a stored procedure takes an out parameter. When this stored procedure is called with this out parameter is already initialized to something, does this situation cause an exception? thanks.

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• alter mysqldump file before import

  - by julio

  Hi-- I have a mysqldump file created from an earlier version of a product that can't be imported into a new version of the product, since the db structure has changed slightly (mainly altering a column that was NOT NULL DEFAULT 0 to UNIQUE KEY DEFAULT NULL). If I just import the old dump file, it will error out since the column that has default values of 0 now breaks the UNIQUE constraint. It would be easy enough to either manually alter the mysqldump file, or import into a temp table and change it, then copy to the new table. However, is there a way to do this programatically, so it will be repeatable and not manual? (this will need to happen for many instances of this product). I'm thinking something like disabling key constraints for the import, then setting all values that = 0 to NULL, then re-enabling the key constraints? Is this possible? Any help appreciated.

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• DateTime in SqlServer VisualStudio C#

  - by menacheb

  Hi, I Have a DataBase in my project With Table named 'ProcessData' and columns named 'Start_At' (Type: DateTime) and 'End_At' (Type: DateTime) . When I try to enter a new record into this table, it enter the data in the following format: 'YYYY/MM/DD HH:mm', when I actualy want it to be in that format: 'YYYY/MM/DD HH:mm:ss' (the secondes dosen't apper). Does anyone know why, and what should I do in order to fix this? Here is the code I using: con = new SqlConnection("...."); String startAt = "20100413 11:05:28"; String endAt = "20100414 11:05:28"; ... con.Open();//open the connection, in order to get access to the database SqlCommand command = new SqlCommand("insert into ProcessData (Start_At, End_At) values('" + startAt + "','" + endAt + "')", con); command.ExecuteNonQuery();//execute the 'insert' query. con.Close(); Many thanks

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• Disable animations when ending search in iPhone

  - by camilo

  Hi. A quicky: is there a way to dismiss the keyboard and the searchDisplayController without animation? I was able to do it when the user presses "Cancel", but when the user presses the black "window thingy" above search field (only visible while the user hasn't inserted any text), the animation always occurs, even when I change the delegate functions. Is there a way to control this, or as an alternative, to disable the user to end searching by pressing the black window? Thanks in advance.

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• Designing a table to store EXIF data

  - by rafale

  I'm looking to get the best performance out of querying a table containing EXIF data. The queries in question will only search the EXIF data for the specified strings and return the row index on a match. With that said, would it better to store the EXIF data in a table with separate columns for each of the tags, or would storing all of the tags in a single column as one long delimited string suit me just as well? There are around 115 EXIF tags I'll be storing, and each record would be around 1500 to 2000 chars in length if concatenated into a single string.

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• Returning multiple aggregate functions as rows

  - by SDLFunTimes

  I need some help formulating a select statement. I need to select the total quantity shipped for each part with a distinct color. So the result should be a row with the color name and the total. Here's my schema: create table s ( sno char(5) not null, sname char(20) not null, status smallint, city char(15), primary key (sno) ); create table p ( pno char(6) not null, pname char(20) not null, color char(6), weight smallint, city char(15), primary key (pno) ); create table sp ( sno char(5) not null, pno char(6) not null, qty integer not null, primary key (sno, pno) );

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• plot a line graph in vb.net

  - by Husna5207

  this is my function for plotting a graph in vb.net how I'm going to replace the ("Jon", 10),("Jordan", 30) with a value that i search from database ? Private Sub chart_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chart_btn.Click Chart1.Series("Student").Points.AddXY("Jon", 10) Chart1.Series("Student").Points.AddXY("Jon", 10) Chart1.Series("Student").ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Bar End Sub

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• Data historian queries

  - by Scott Dennis

  Hi, I have a table that contains data for electric motors the format is: DATE(DateTime) | TagName(VarChar(50) | Val(Float) | 2009-11-03 17:44:13.000 | Motor_1 | 123.45 2009-11-04 17:44:13.000 | Motor_1 | 124.45 2009-11-05 17:44:13.000 | Motor_1 | 125.45 2009-11-03 17:44:13.000 | Motor_2 | 223.45 2009-11-04 17:44:13.000 | Motor_2 | 224.45 Data for each motor is inserted daily, so there would be 31 Motor_1s and 31 Motor_2s etc. We do this so we can trend it on our control system displays. I am using views to extract last months max val and last months min val. Same for this months data. Then I join the two and calculate the difference to get the actual run hours for that month. The "Val" is a nonresetable Accumulation from a PLC(Controller). This is my query for Last months Max Value: SELECT TagName, Val AS Hours FROM dbo.All_Data_From_Last_Mon AS cur WHERE (NOT EXISTS (SELECT TagName, Val FROM dbo.All_Data_From_Last_Mon AS high WHERE (TagName = cur.TagName) AND (Val > cur.Val))) This is my query for Last months Max Value: SELECT TagName, Val AS Hours FROM dbo.All_Data_From_Last_Mon AS cur WHERE (NOT EXISTS (SELECT TagName, Val FROM dbo.All_Data_From_Last_Mon AS high WHERE (TagName = cur.TagName) AND (Val < cur.Val))) This is the query that calculates the difference and runs a bit slow: SELECT dbo.Motors_Last_Mon_Max.TagName, STR(dbo.Motors_Last_Mon_Max.Hours - dbo.Motors_Last_Mon_Min.Hours, 12, 2) AS Hours FROM dbo.Motors_Last_Mon_Min RIGHT OUTER JOIN dbo.Motors_Last_Mon_Max ON dbo.Motors_Last_Mon_Min.TagName = dbo.Motors_Last_Mon_Max.TagName I know there is a better way. Ultimately I just need last months total and this months total. Any help would be appreciated. Thanks in advance

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• is there a better way to write this frankenstein LINQ query that searches for values in a child tabl

  - by MRV

  I have a table of Users and a one to many UserSkills table. I need to be able to search for users based on skills. This query takes a list of desired skills and searches for users who have those skills. I want to sort the users based on the number of desired skills they posses. So if a users only has 1 of 3 desired skills he will be further down the list than the user who has 3 of 3 desired skills. I start with my comma separated list of skill IDs that are being searched for: List<short> searchedSkillsRaw = skills.Value.Split(',').Select(i => short.Parse(i)).ToList(); I then filter out only the types of users that are searchable: List<User> users = (from u in db.Users where u.Verified == true && u.Level > 0 && u.Type == 1 && (u.UserDetail.City == city.SelectedValue || u.UserDetail.City == null) select u).ToList(); and then comes the crazy part: var fUsers = from u in users select new { u.Id, u.FirstName, u.LastName, u.UserName, UserPhone = u.UserDetail.Phone, UserSkills = (from uskills in u.UserSkills join skillsJoin in configSkills on uskills.SkillId equals skillsJoin.ValueIdInt into tempSkills from skillsJoin in tempSkills.DefaultIfEmpty() where uskills.UserId == u.Id select new { SkillId = uskills.SkillId, SkillName = skillsJoin.Name, SkillNameFound = searchedSkillsRaw.Contains(uskills.SkillId) }), UserSkillsFound = (from uskills in u.UserSkills where uskills.UserId == u.Id && searchedSkillsRaw.Contains(uskills.SkillId) select uskills.UserId).Count() } into userResults where userResults.UserSkillsFound > 0 orderby userResults.UserSkillsFound descending select userResults; and this works! But it seems super bloated and inefficient to me. Especially the secondary part that counts the number of skills found. Thanks for any advice you can give. --r

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• What are prepared statements?

  - by alwayslearning

  What are prepared statements in the context of relational databases? How do they help and when should I consider using them?

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• Interesting Row_Number() bug

  - by Joel Coehoorn

  I was playing with the Stack Exchange Data Explorer and ran this query: http://odata.stackexchange.com/stackoverflow/q/2828/rising-stars-top-50-users-ordered-on-rep-per-day Notice down in the results, rows 11 and 12 have the same value and so are mis-numbered, even though the row_number() function takes the same order by parameter as the query. I know the correct fix here is to specify an additional tie-breaker column in the order by clauses, but I'm more curious as to why/how the row_number() function returned different results on the same data? If it makes a difference anywhere, this runs on Azure.

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