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• Indexed key vs indexed separate columns, which one is faster ?

  - by Jerry

  In MYSQL, from a pure performance perspective, if I have a table with large amount of data with 10/1 read/write ratio. is it faster in read/write performance to have 4 search criteria in separate columns and all indexed or have them combined in to one single string acting as a key and store in one indexed column ? e.g. say this table with 5 columns, first name, last name, sex, country and file where the first four columns will ALWAYS be given as a part of search parameters in a search or have a table with two columns, key and file. where the value of key can be john-smith-male-australia ?? I don't quite get the pros and cons. the point I try to stress is the fact that all parameters will be given.in a search.

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• Converting time/date from XML file into MYSQL format

  - by IconicDigital

  One of the affiliate networks provides a feed with the following time/date format. <startDate>1349992800000</startDate> <endDate>1355266799999</endDate> My problem is I am trying to convert this to a MYSQL format, I have tried mktime and strtotime with no luck the date seems to come out wrong. I know this is the time since the Equinox, I am just not sure how to convert this to a MYSQL format.

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• Incorrect syntax near ')' calling storedproc with GETDATE

  - by Nat

  Maybe I am having a moment of 'afternoon', but can anyone explain why I get Msg 102, Level 15, State 1, Line 2 Incorrect syntax near ')'. When running CREATE PROC DisplayDate ( @DateVar DATETIME ) AS BEGIN SELECT @DateVar END GO EXEC DisplayDate GETDATE();

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• last day of the current month?

  - by Surya sasidhar

  hi, i have to get the last day of the current month. how can i get

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• Why is this postgresql query so slow?

  - by user315975

  I'm no database expert, but I have enough knowledge to get myself into trouble, as is the case here. This query SELECT DISTINCT p.* FROM points p, areas a, contacts c WHERE ( p.latitude > 43.6511659465 AND p.latitude < 43.6711659465 AND p.longitude > -79.4677941889 AND p.longitude < -79.4477941889) AND p.resource_type = 'Contact' AND c.user_id = 6 is extremely slow. The points table has fewer than 2000 records, but it takes about 8 seconds to execute. There are indexes on the latitude and longitude columns. Removing the clause concering the resource_type and user_id make no difference. The latitude and longitude fields are both formatted as number(15,10) -- I need the precision for some calculations. There are many, many other queries in this project where points are compared, but no execution time problems. What's going on?

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• Ways to implement tags - pros and cons of each

  - by bobobobo

  Related Using SO as an example, what is the most sensible way to manage tags if you anticipate they will change often? Way 1: Seriously denormalized (comma delimited) table posts +--------+-----------------+ | postId | tags | +--------+-----------------+ | 1 | c++,search,code | Here tags are comma delimited. Pros: Tags are retrieved at once with a single select query. Updating tags is simple. Easy and cheap to update. Cons: Extra parsing on tag retrieval, difficult to count how many posts use which tags. (alternatively, if limited to something like 5 tags) table posts +--------+-------+-------+-------+-------+-------+ | postId | tag_1 | tag_2 | tag_3 | tag_4 | tag_5 | +--------+-------+-------+-------+-------+-------+ | 1 | c++ |search | code | | | Way 2: "Slightly normalized" (separate table, no intersection) table posts +--------+-------------------+ | postId | title | +--------+-------------------+ | 1 | How do u tag? | table taggings +--------+---------+ | postId | tagName | +--------+---------+ | 1 | C++ | | 1 | search | Pros: Easy to see tag counts (count(*) from taggings where tagName='C++'). Cons: tagName will likely be repeated many, many times. Way 3: The cool kid's (normalized with intersection table) table posts +--------+---------------------------------------+ | postId | title | +--------+---------------------------------------+ | 1 | Why is a raven like a writing desk? | table tags +--------+---------+ | tagId | tagName | +--------+---------+ | 1 | C++ | | 2 | search | | 3 | foofle | table taggings +--------+---------+ | postId | tagId | +--------+---------+ | 1 | 1 | | 1 | 2 | | 1 | 3 | Pros: No repeating tag names. More girls will like you. Cons: More expensive to change tags than way #1.

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• How do I create a multiple-table check constraint?

  - by Zack Peterson

  Please imagine this small database... Diagram Tables Volunteer Event Shift EventVolunteer ========= ===== ===== ============== Id Id Id EventId Name Name EventId VolunteerId Email Location VolunteerId Phone Day Description Comment Description Start End Associations Volunteers may sign up for multiple events. Events may be staffed by multiple volunteers. An event may have multiple shifts. A shift belongs to only a single event. A shift may be staffed by only a single volunteer. A volunteer may staff multiple shifts. Check Constraints Can I create a check constraint to enforce that no shift is staffed by a volunteer that's not signed up for that shift's event? Can I create a check constraint to enforce that two overlapping shifts are never staffed by the same volunteer?

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• How do you integrate MYOB Exo Business (Exonet) to a .NET application?

  - by Tenacious T

  I'm currently exploring the possibility of integrating MYOB Exo Business (Exonet) to a shopping cart developed using ASP.NET 3.5. I understand that there is an MYOB ODBC driver to use as a connector. Is this the only way to do it?

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• Which of these queries is preferable?

  - by bread

  I've written the same query as a subquery and a self-join. Is there any obvious argument for one over the other here? SUBQUERY: SELECT prod_id, prod_name FROM products WHERE vend_id = (SELECT vend_id FROM products WHERE prod_id = ‘DTNTR’); SELF-JOIN: SELECT p1.prod_id, p1.prod_name FROM products p1, products p2 WHERE p1.vend_id = p2.vend_id AND p2.prod_id = ‘DTNTR’;

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• jpa join query on a subclass

  - by Brian

  I have the following relationships in JPA (hibernate). Object X has two subclasses, Y and Z. Object A has a manyToOne relationship to object X. (Note, this is a one-sided relationship so object X cannot see object A). Now, I want to get the max value of a column in object A, but only where the relationship is of a specific subtype, ie...Y. So, that equates to...get the max value of column1 in object A, across all instances of A where they have a relationship with Y. Is this possible? I'm a bit lost as how to query it. I was thinking of something like: String query = "SELECT MAX(a.columnName) FROM A a join a.x; Query query = super.entityManager.createQuery(query); query.execute(); However that doesn't take account of the subclass of X...so I'm a bit lost. Any help would be much appreciated.

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• trouble connecting to MySql DB (PHP)

  - by user332817

  Hi I have the following PHP code to connect to my db. <?php ob_start(); $host="localhost"; // Host name $username="root"; // Mysql username $password=""; // Mysql password $db_name="test"; // Database name $tbl_name="members"; // Table name // Connect to server and select databse. mysql_connect("$host", "$username", "$password")or die("cannot connect"); ?> however I get the following error: Warning: mysql_connect() [function.mysql-connect]: [2002] A connection attempt failed because the connected party did not (trying to connect via tcp://localhost:3306) in C:\Program Files (x86)\EasyPHP-5.3.2i\www\checklogin.php on line 11 Warning: mysql_connect() [function.mysql-connect]: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. in C:\Program Files (x86)\EasyPHP-5.3.2i\www\checklogin.php on line 11 Fatal error: Maximum execution time of 30 seconds exceeded in C:\Program Files (x86)\EasyPHP-5.3.2i\www\checklogin.php on line 11 I am able to add a db/tables via phpmyadmin but I cant connect using php. here is a screenshot of my phpmyadmin page: http://img294.imageshack.us/img294/1589/sqls.jpg any help would be appreciated, thanks in advance.

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• sql data source

  - by George

  I have a table (EmployeeID,EmployeeName,ManagerID) How can I create a sqldatasource to include the ManagerName from the EmployeeName given EmployeeID = ManagerID? In my gridview after dragging a dropdownlist what bindings should I do to display the managerName? Is it possible to use it without writing custom select,insert,delete,update? If not what are the steps I need to do to write the whole thing i.e. custom grid and source? Thank you very much

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• performing more than one Where in query return null!!! why? how to fix this?

  - by Sadegh

  hi, i have wrote a method that filters output with provided query and return it. when one Where excuted; it return correct output but when more than one Where excuted; output is null and Exception occured with message "Enumeration yielded no results". why? how i can fix it? public IQueryable<SearchResult> PerformSearch(string query, int skip = 0, int take = 5) { if (!string.IsNullOrEmpty(query)) { var queryList = query.Split('+').ToList(); var results = GENERATERESULTS(); string key; foreach (string _q in queryList) { if (_q.StartsWith("(") && _q.EndsWith(")")) { key = _q.Replace("(", "").Replace(")", ""); results = results.Where(q => q.Title.Contains(key, StringComparison.CurrentCultureIgnoreCase)); } else if (_q.StartsWith("\"") && _q.EndsWith("\"")) { key = _q.Replace("\"", "").Replace("\"", ""); results = results.Where(q => q.Title.Contains(key, StringComparison.CurrentCulture)); } else if (_q.StartsWith("-(") && _q.EndsWith(")")) { key = _q.Replace("-(", "").Replace(")", ""); results = results.Where(q=> !q.Title.Contains(key, StringComparison.CurrentCultureIgnoreCase)); } else { key = _q; results = results.Where(q => q.Title.Contains(key, StringComparison.CurrentCulture)); } } this._Count = results.Count(); results = results.Skip(skip).Take(take); this._EndOn = DateTime.Now; this.ExecutionTime(); return results; } else return null; } thanks in advance ;)

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• mysql: get all rows into 1 column

  - by andufo

  hi, i have 3 tables: post (id_post, title) tag (id_tag, name) post_tag (id_post_tag, id_post, id_tag) Lets suppose that id_post 3 has 4 linked tags 1,2,3,4 (soccer, basket, tennis and golf). Is there a way to return something like this in ONE row? col 1 id_post = 3 col 2 tags = soccer basket tennis golf Thanks

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• Stop invalid data in a attribute with foreign key constraint using triggers?

  - by Eternal Learner

  How to specify a trigger which checks if the data inserted into a tables foreign key attribute, actually exists in the references table. If it exist no action should be performed , else the trigger should delete the inserted tuple. Eg: Consider have 2 tables R(A int Primary Key) and S(B int Primary Key , A int Foreign Key References R(A) ) . I have written a trigger like this : Create Trigger DelS BEFORE INSERT ON S FOR EACH ROW BEGIN Delete FROM S where New.A <> ( Select * from R;) ); End; I am sure I am making a mistake while specifying the inner sub query within the Begin and end Blocks of the trigger. My question is how do I make such a trigger ?

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• on sql basic question

  - by puneet

  Q. display all the salaries and display total sal at the end? Q. how many column are inserted in a single table?

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• advanced select in Stored Procedure

  - by Auro

  Hey i got this Table: CREATE TABLE Test_Table ( old_val VARCHAR2(3), new_val VARCHAR2(3), Updflag NUMBER, WorkNo NUMBER ); and this is in my Table: INSERT INTO Test_Table (old_val, new_val, Updflag , WorkNo) VALUES('1',' 20',0,0); INSERT INTO Test_Table (old_val, new_val, Updflag , WorkNo) VALUES('2',' 20',0,0); INSERT INTO Test_Table (old_val, new_val, Updflag , WorkNo) VALUES('2',' 30',0,0); INSERT INTO Test_Table (old_val, new_val, Updflag , WorkNo) VALUES('3',' 30',0,0); INSERT INTO Test_Table (old_val, new_val, Updflag , WorkNo) VALUES('4',' 40',0,0); INSERT INTO Test_Table (old_val, new_val, Updflag , WorkNo) VALUES('4',' 40',0,0); now my Table Looks like this: Row Old_val New_val Updflag WorkNo 1 '1' ' 20' 0 0 2 '2' ' 20' 0 0 3 '2' ' 30' 0 0 4 '3' ' 30' 0 0 5 '4' ' 40' 0 0 6 '5' ' 40' 0 0 (if the value in the new_val column are same then they are together and the same goes to old_val) so in the example above row 1-4 are together and row 5-6 at the moment i have in my Stored Procedure a cursor: SELECT t1.Old_val, t1.New_val, t1.updflag, t1.WorkNo FROM Test_Table t1 WHERE t1.New_val = ( SELECT t2.New_val FROM Test_Table t2 WHERE t2.Updflag = 0 AND t2.Worknr = 0 AND ROWNUM = 1 ) the output is this: Row Old_val New_val Updflag WorkNo 1 1 20 0 0 2 2 20 0 0 my Problem is, i dont know how to get row 1 to 4 with one select. (i had an idea with 4 sub-querys but this wont work if its more data that matches together) does anyone of you have an idea?

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• Double Inner Join generates unexpected error

  - by Itamar Marom

  In my database I have three tables: Users: UserID (Auto Numbering), UserName, UserPassword and a few other unimportant fields. PrivateMessages: MessageID (Auto Numbering), SenderID and a few other fields defining the message content. MessageStatus: MessageID, ReceiverID, MessageWasRead (Boolean) What I need is a query to which I input a user's id and I get all the private messages he has received. In addition, I also need to receive each message's sender UserName. For this I wrote the following query: SELECT Users.*, PrivateMessages.*, MessageStatus.* FROM PrivateMessages INNER JOIN Users ON PrivateMessages.SenderID = Users.UserID INNER JOIN MessageStatus ON PrivateMessages.MessageID = MessageStatus.MessageID WHERE MessageStatus.ReceiverID=[@userid]; But for some reason when I try saving it in my Access database, I get the following error (translated to English by me, since my office is in a different language): Syntax error (missing operator) at expression: "PrivateMessages.SenderID = Users.UserID INNER JOIN MessageStatus ON PrivateMessages.MessageID = MessageStatus.MessageI". Any ideas what could cause this? Thanks.

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• Getting counts of 0 from a query with a double group by

  - by Maltiriel

  I'm trying to write a query that gets the counts for a table (call it item) categorized by two different things, call them type and code. What I'm hoping for as output is the following: Type Code Count 1 A 3 1 B 0 1 C 10 2 A 0 2 B 13 2 C 2 And so forth. Both type and code are found in lookup tables, and each item can have just one type but more than one code, so there's also a pivot (aka junction or join) table for the codes. I have a query that can get this result: Type Code Count 1 A 3 1 C 10 2 B 13 2 C 2 and it looks like (with join conditions omitted): SELECT typelookup.name, codelookup.name, COUNT(item.id) FROM typelookup LEFT OUTER JOIN item JOIN itemcodepivot RIGHT OUTER JOIN codelookup GROUP BY typelookup.name, codelookup.name Is there any way to alter this query to get the results I'm looking for? This is in MySQL, if that matters. I'm not actually sure this is possible all in one query, but if it is I'd really like to know how. Thanks for any ideas.

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• Stored Procedure: Reducing Table Data

  - by SumGuy

  Hi Guys, A simple question about Stored Procedures. I have one stored procedure collecting a whole bunch of data in a table. I then call this procedure from within another stored procedure. I can copy the data into a new table created in the calling procedure but as far as I can see the tables have to be identical. Is this right? Or is there a way to insert only the data I want? For example.... I have one procedure which returns this: SELECT @batch as Batch, @Count as Qty, pd.Location, cast(pd.GL as decimal(10,3)) as [Length], cast(pd.GW as decimal(10,3)) as Width, cast(pd.GT as decimal(10,3)) as Thickness FROM propertydata pd GROUP BY pd.Location, pd.GL, pd.GW, pd.GT I then call this procedure but only want the following data: DECLARE @BatchTable TABLE ( Batch varchar(50), [Length] decimal(10,3), Width decimal(10,3), Thickness decimal(10,3), ) INSERT @BatchTable (Batch, [Length], Width, Thickness) EXEC dbo.batch_drawings_NEW @batch So in the second command I don't want the Qty and Location values. However the code above keeps returning the error: "Insert Error: Column name or number of supplied values does not match table"

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• How to check with PHP does a SQL database already have

  - by Dan Horvat

  I've tried to find the answer to this question but none of the answers fit. I have two databases, one has 15.000.000 entries and I want to extract the necessary data and store it in a much smaller database with around 33.000 entries. Both databases are open at the same time. Or at least they should be. While having the big database open and extracting the entries from it, is it possible to check whether the value already exists in the smaller database? I just need some generic way which checks that.

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• Reading from an write-only(OUT) parameter in pl/sql

  - by sqlgrasshopper5

  When I tried writing to an read-only parameter(IN) of a function, Oracle complains with an error. But that is not the case when reading from an write-only(OUT) parameter of a function. Oracle silently allows this without any error. What is the reason for this behaviour?. The following code executes without any assignment happening to "so" variable: create or replace function foo(a OUT number) return number is so number; begin so := a; --no assignment happens here a := 42; dbms_output.put_line('HiYA there'); dbms_output.put_line('VAlue:' || so); return 5; end; / declare somevar number; a number := 6; begin dbms_output.put_line('Before a:'|| a); somevar := foo(a); dbms_output.put_line('After a:' || a); end; / Here's the output I got: Before a:6 HiYA there VAlue: After a:42

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• Any way to optimize this MySQL query?

  - by manyxcxi

  My table looks like this: `MyDB`.`Details` ( `id` bigint(20) NOT NULL, `run_id` int(11) NOT NULL, `element_name` varchar(255) NOT NULL, `value` text, `line_order` int(11) default NULL, `column_order` int(11) default NULL ); I have the following SELECT statement in a stored procedure SELECT RULE ,TITLE ,SUM(IF(t.PASSED='Y',1,0)) AS PASS ,SUM(IF(t.PASSED='N',1,0)) AS FAIL FROM ( SELECT a.line_order ,MAX(CASE WHEN a.element_name = 'PASSED' THEN a.`value` END) AS PASSED ,MAX(CASE WHEN a.element_name = 'RULE' THEN a.`value` END) AS RULE ,MAX(CASE WHEN a.element_name = 'TITLE' THEN a.`value` END) AS TITLE FROM Details a WHERE run_id = runId GROUP BY line_order ) t GROUP BY RULE, TITLE; *runId is an input parameter to the stored procedure. This query takes about 14 seconds to run. The table has 214856 rows, and the particular run_id I am filtering on has 162204 records. It's not on a super high power machine, but I feel like I could be doing this more efficiently. My main goal is to summarize by Rule and Title and show Pass and Fail count columns.

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• How to calculate siteamps priority value based on views?

  - by stacker

  How can I calculate sitemap url priority based on the views count of the article / comments count?

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• integrating jquery with AJAX using MVC for ddl/html.dropdownlist

  - by needhelp

  the situation: a user on the page in question selects a category from a dropdown which then dynamically populates all the users of that category in a second dropdown beside it. all the data is being retrieved using LinqtoSQL and i was wondering if this can be done a) using html.dropdownlist in a strongly typed view? b) using jquery to trigger the ajax request on selected index change instead of a 'populate' button trigger? sorry i dont have code as what i was trying really wasnt working at all. I am having trouble with how to do it conceptually and programatically! will appreciate any links to examples etc greatly! thanks in advance! EDIT: this is kind of what i was trying to achieve.. first the ViewPage: <script type="text/javascript"> $(document).ready function TypeSearch() { $.getJSON("/Home/Type", null, function(data) { //dont know what to do here }); } </script> <p> <label for="userType">userType:</label> <%= Html.DropDownList("userType") %> <%= Html.ValidationMessage("userType", "*") %> <input type="submit" runat="server" onclick="TypeSearch()" /> <label for="accountNumber">accountNumber:</label> <%= Html.DropDownList("accountNumber") %> <%= Html.ValidationMessage("accountNumber", "*") %> </p> Then home controller action: public ActionResult Type() { string accountType = dropdownvalue; List<Account> accounts = userRep.GetAccountsByType(accountType).ToList(); return Json(accounts); }

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