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  • What should I use to increase performance. View/Query/Temporary Table

    - by Shantanu Gupta
    I want to know the performance of using Views, Temp Tables and Direct Queries Usage in a Stored Procedure. I have a table that gets created every time when a trigger gets fired. I know this trigger will be fired very rare and only once at the time of setup. Now I have to use that created table from triggers at many places for fetching data and I confirms it that no one make any changes in that table. i.e ReadOnly Table. I have to use this tables data along with multiple tables to join and fetch result for further queries say select * from triggertable By Using temp table select ... into #tx from triggertable join t2 join t3 and so on select a,b, c from #tx --do something select d,e,f from #tx ---do somethign --and so on --around 6-7 queries in a row in a stored procedure. By Using Views create view viewname ( select ... from triggertable join t2 join t3 and so on ) select a,b, c from viewname --do something select d,e,f from viewname ---do somethign --and so on --around 6-7 queries in a row in a stored procedure. This View can be used in other places as well. So I will be creating at database rather than at sp By Using Direct Query select a,b, c from select ... into #tx from triggertable join t2 join t3 join ... --do something select a,b, c from select ... into #tx from triggertable join t2 join t3 join ... --do something . . --and so on --around 6-7 queries in a row in a stored procedure. Now I can create a view/temporary table/ directly query usage in all upcoming queries. What would be the best to use in this case.

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  • change postgres date format

    - by Jay
    Is there a way to change the default format of a date in Postgres? Normally when I query a Postgres database, dates come out as yyyy-mm-dd hh:mm:ss+tz, like 2011-02-21 11:30:00-05. But one particular program the dates come out yyyy-mm-dd hh:mm:ss.s, that is, there is no time zone and it shows tenths of a second. Apparently something is changing the default date format, but I don't know what or where. I don't think it's a server-side configuration parameter, because I can access the same database with a different program and I get the format with the timezone. I care because it appears to be ignoring my "set timezone" calls in addition to changing the format. All times come out EST. Additional info: If I write "select somedate from sometable" I get the "no timezone" format. But if I write "select to_char(somedate::timestamptz, 'yyyy-mm-dd hh24:mi:ss-tz')" then timezones work as I would expect. This really sounds to me like something is setting all timestamps to implicitly be "to_char(date::timestamp, 'yyyy-mm-dd hh24:mi:ss.m')". But I can't find anything in the documentation about how I would do this if I wanted to, nor can I find anything in the code that appears to do this. Though as I don't know what to look for, that doesn't prove much.

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  • postgres subquery w/ derived column

    - by Wells
    The following query won't work, but it should be clear what I'm trying to do: split the value of 't' on space and use the last element in that array in the subquery (as it will match tl). Any ideas how to do this? Thanks! SELECT t, y, "type", regexp_split_to_array(t, ' ') as t_array, sum(dr), ( select uz from f.tfa where tl = t_array[-1] ) as uz, sc FROM padres.yd_fld WHERE y = 2010 AND pos <> 0 GROUP BY t, y, "type", sc;

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  • MySQL whats wrong with my foreign keys?

    - by Skiy
    Hello, what is wrong with the two foreign keys which I have marked with comments? create database db; use db; create table Flug( Flugbez varchar(20), FDatum Date, Ziel varchar(20), Flugzeit int, Entfernung int, Primary Key (Flugbez, FDatum)); create table Flugzeugtyp( Typ varchar(20), Hersteller varchar(20), SitzAnzahl int, Reisegeschw int, primary key (Typ) ); create table flugzeug( Typ varchar(20), SerienNr int, AnschDatum Date, FlugStd int, primary key(Typ,SerienNr), foreign key(Typ) references Flugzeugtyp(Typ)); create table Abflug( Flugbez varchar(20), FDatum Date, Typ varchar(20), Seriennr int, Kaptaen varchar(20), Primary key(Flugbez,FDatum,Typ,SerienNr), Foreign key(Flugbez) references Flug(Flugbez), -- Foreign key(FDatum) references Flug(FDatum), Foreign key(Typ) references Flugzeugtyp(Typ) -- ,Foreign key(SerienNr) references Flugzeug(SerienNr) ); When I uncomment these, I get: ERROR 1005 (HY000): Can't create table 'db.abflug' (errno: 150)

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  • Multiple conditions with CASE statements

    - by Pavan Reddy
    I need to query some data. here is the query that i have constructed but which isn't workig fine for me. For this example I am using AdventureWorks database. SELECT * FROM [Purchasing].[Vendor] WHERE PurchasingWebServiceURL LIKE case // In this case I need all rows to be returned if @url is '' or 'ALL' or NULL when (@url IS null OR @url = '' OR @url = 'ALL') then ('''%'' AND PurchasingWebServiceURL IS NULL') //I need all records which are blank here including nulls when (@url = 'blank') then (''''' AND PurchasingWebServiceURL IS NULL' ) //n this condition I need all record which are not like a particular value when (@url = 'fail') then ('''%'' AND PurchasingWebServiceURL NOT LIKE ''%treyresearch%''' ) //Else Match the records which are `LIKE` the input value else '%' + @url + '%' end This is not working for me. How can I have multiple where condition clauses in the THEN of the the same CASE? How can I make this work?

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  • Adding Information in SQLite

    - by Cam
    Hi All, I am having trouble with my Android App when adding information into SQLite. I am relatively new to Java/SQLite and though I have followed a lot of tutorials on SQLite and have been able to get the example code to run I am unable to get tables to be created and data to import when running my own app. I have included my code in two Java files Questions (Main Program) and QuestionData (helper class represents the database). Questions.java: public class Questions extends Activity { private QuestionData questions; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.quiztest); questions = new QuestionData(this); try { Cursor cursor = getQuestions(); showQuestions(cursor); } finally { questions.close(); } } private Cursor getQuestions() { //Select Query String loadQuestions = "SELECT * FROM questionlist"; SQLiteDatabase db = questions.getReadableDatabase(); Cursor cursor = db.rawQuery(loadQuestions, null); startManagingCursor(cursor); return cursor; } private void showQuestions(Cursor cursor) { // Collect String Values from Query and Display them this part of the code is wokring fine when there is data present. QuestionData.java public class QuestionData extends SQLiteOpenHelper { private static final String DATABASE_NAME = "TriviaQuiz.db" ; private static final int DATABASE_VERSION = 2; public QuestionData(Context ctx) { super(ctx, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE questionlist (_id INTEGER PRIMARY KEY AUTOINCREMENT, QID TEXT, QQuestion TEXT, QAnswer TEXT, QOption1 TEXT, QOption2 TEXT, QOption3 TEXT, QCategoryTagLvl1 TEXT, QCategoryTagLvl2 TEXT, QOptionalTag1 TEXT, QOptionalTag2 TEXT, QOptionalTag3 TEXT, QOptionalTag4 TEXT, QOptionalTag5 TEXT, QTimePeriod TEXT, QDifficultyRating TEXT, QGenderBias TEXT, QAgeBias TEXT, QRegion TEXT, QWikiLink TEXT, QValidationLink1 TEXT, QValidationLink2 TEXT, QHint TEXT, QLastValidation TEXT, QNotes TEXT, QMultimediaType TEXT, QMultimediaLink TEXT, QLastAsked TEXT);"); db.execSQL("INSERT INTO questionlist (_id, QID, QQuestion, QAnswer, QOption1, QOption2, QOption3, QCategoryTagLvl1, QCategoryTagLvl2, QOptionalTag1, QOptionalTag2, QOptionalTag3, QOptionalTag4, QOptionalTag5, QTimePeriod, QDifficultyRating, QGenderBias, QAgeBias, QRegion, QWikiLink, QValidationLink1, QValidationLink2, QHint, QLastValidation, QNotes, QMultimediaType, QMultimediaLink, QLastAsked)"+ "VALUES (null,'Q00001','Example','Ans1','Q1','Q2','Q3','Q4','','','','','','','','','','','','','','','','','','','','')"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME); onCreate(db); } } Any suggestions at all would be great. I have tried debugging which suggests that the database does not exist. Thanks in advance for your assistance.

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  • Can I concatenate multiple MySQL rows into one field?

    - by Dean
    Using MySQL, I can do something like select hobbies from peoples_hobbies where person_id = 5; and get: shopping fishing coding but instead I just want 1 row, 1 col: shopping, fishing, coding The reason is that I'm selecting multiple values from multiple tables, and after all the joins I've got a lot more rows than I'd like. I've looked for a function on MySQL Doc and it doesn't look like the CONCAT or CONCAT_WS functions accept result sets, so does anyone here know how to do this?

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  • What is this hacker trying to do?

    - by JW
    If you do a search for: http://www.google.co.uk/search?q=0x57414954464F522044454C4159202730303A30303A313527&hl=en&start=30&sa=N you will see a lot of examples of an attempted hack along the lines of: 1) declare @q varchar(8000) select @q = 0x57414954464F522044454C4159202730303A30303A313527 exec(@q) -- What is exactly is it trying to do? Which db is it trying to work on? Do you know of any advisories about this?

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  • Access is re-writing - and breaking - my query!

    - by FrustratedWithFormsDesigner
    I have a query in MS Access (2003) that makes use of a subquery. The subquery part looks like this: ...FROM (SELECT id, dt, details FROM all_recs WHERE def_cd="ABC-00123") AS q1,... And when I switch to Table View to verify the results, all is OK. Then, I wanted the result of this query to be printed on the page header for a report (the query returns a single row that is page-header stuff). I get an error because the query is suddenly re-written as: ...FROM [SELECT id, dt, details FROM all_recs WHERE def_cd="ABC-00123"; ] AS q1,... So it's Ok that the round brackets are automatically replaced by square brackets, Access feels it needs to do that, fine! But why is it adding the ; into the subquery, which causes it to fail? I suppose I could just create new query objects for these subqueries, but it seems a little silly that I should have to do that.

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  • How can I count existing and non-existing values with MySQL?

    - by jaya malladi
    I am new to MySQL. I have a table with answer ids. Answers can look like this:a1, a2, a3 ..., but due to some problems some are NULL, some are blank, and some are others like 1 a etc. Now I want to calculate the count of ids with a1 a2 a3 distinctly. But how is it possible to do this leaving others like NULL, blanks and garbage. The output should look like this atype count a1 45 a2 0 a3 56 If there is no row entry for a particular answer, the count should be 0.

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  • Indexing table with duplicates MySQL/MSSQL with millions of records

    - by Tesnep
    I need help in indexing in MySQL. I have a table in MySQL with following rows: ID Store_ID Feature_ID Order_ID Viewed_Date Deal_ID IsTrial The ID is auto generated. Store_ID goes from 1 - 8. Feature_ID from 1 - let's say 100. Viewed Date is Date and time on which the data is inserted. IsTrial is either 0 or 1. You can ignore Order_ID and Deal_ID from this discussion. There are millions of data in the table and we have a reporting backend that needs to view the number of views in a certain period or overall where trial is 0 for a particular store id and for a particular feature. The query takes the form of: select count(viewed_date) from theTable where viewed_date between '2009-12-01' and '2010-12-31' and store_id = '2' and feature_id = '12' and Istrial = 0 In MSSQL you can have a filtered index to use for Istrial. Is there anything similar to this in MySQL? Also, Store_ID and Feature_ID have a lot of duplicate data. I created an index using Store_ID and Feature_ID. Although this seems to have decreased the search period, I need better improvement than this. Right now I have more than 4 million rows. To search for a particular query like the one above, it looks at 3.5 million rows in order to give me the count of 500k rows. PS. I forgot to add view_date filter in the query. Now I have done this.

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  • Suggestion on Database structure for relational data

    - by miccet
    Hi there. I've been wrestling with this problem for quite a while now and the automatic mails with 'Slow Query' warnings are still popping in. Basically, I have Blogs with a corresponding table as well as a table that keeps track of how many times each Blog has been viewed. This last table has a huge amount of records since this page is relatively high traffic and it logs every hit as an individual row. I have tried with indexes on the fields that are included in the WHERE clause, but it doesn't seem to help. I have also tried to clean the table each week by removing old ( 1.weeks) records. SO, I'm asking you guys, how would you solve this? The query that I know is causing the slowness is generated by Rails and looks like this: SELECT count(*) AS count_all FROM blog_views WHERE (created_at >= '2010-01-01 00:00:01' AND blog_id = 1); The tables have the following structures: CREATE TABLE IF NOT EXISTS 'blogs' ( 'id' int(11) NOT NULL auto_increment, 'name' varchar(255) default NULL, 'perma_name' varchar(255) default NULL, 'author_id' int(11) default NULL, 'created_at' datetime default NULL, 'updated_at' datetime default NULL, 'blog_picture_id' int(11) default NULL, 'blog_picture2_id' int(11) default NULL, 'page_id' int(11) default NULL, 'blog_picture3_id' int(11) default NULL, 'active' tinyint(1) default '1', PRIMARY KEY ('id'), KEY 'index_blogs_on_author_id' ('author_id') ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ; And CREATE TABLE IF NOT EXISTS 'blog_views' ( 'id' int(11) NOT NULL auto_increment, 'blog_id' int(11) default NULL, 'ip' varchar(255) default NULL, 'created_at' datetime default NULL, 'updated_at' datetime default NULL, PRIMARY KEY ('id'), KEY 'index_blog_views_on_blog_id' ('blog_id'), KEY 'created_at' ('created_at') ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

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  • Using a trigger to record audit information vs. stored procedure

    - by Germ
    Suppose you have the following... An ASP.NET web application that calls a stored procedure to delete a record. The table has a trigger on it that will insert an audit entry each time a record is deleted. I want to be able to record in the audit entry the username of who deleted the record. What would be the best way to go about achieving this? I know I could remove the trigger and have the delete stored procedure insert the audit entry prior to deleting but are there any other recommeded alternative? If a username was passed as a parameter to the delete stored procedure, is there anyway to get this value in the trigger that's excuted when the record is deleted? I'm just throwing this out there...

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  • Mysql query help needed

    - by Me-and-Coding
    Hi, i have two tables category and hotels where category.id should be equal to hotels.catid. Now how do i select 3 rows from each different category from the hotels table. I have this query: select h.* from hotels h inner join category c on h.catid = c.id order by h.catid, h.hid this selects all records, but i want to select three rows per different category so in all it should return 9 rows with 3 rows for each category. If this can not be done in mysql, you could also suggest php code please. Thanks

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  • SQL Join query, getting ManagerName

    - by user279521
    I have an tblEmployeeProfile & a tblPersonnel. tblPersonnel is an HR table, that consists of all employees in the company; tblEmployeeProfile contains details about an employee's position. tblPersonnel.PersonnelID tblPersonnel.FirstName tblPersonnel.MiddleName tblPersonnel.LastName tblPersonnel.PhoneNumber tblPersonnel.Email tblEmployeeProfile.EmployeeID tblEmployeeProfile.ManagerID tblEmployeeProfile.DepartmentID tblEmployeeProfile.JobCategoryID tblEmployeeProfile.SalaryID I want to return a record with the following fields: EmployeeID, FirstName, MiddleName, LastName, Email, ManagerFullName where EmployeeID = @EmployeeID *tblEmployeeProfile.ManagerID = tblPersonnel.PersonnelID* I can't seem to get the query correct for getting the ManagerFullName

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  • How to limit select items with L2E/S?

    - by orlon
    This code is a no-go var errors = (from error in db.ELMAH_Error select new { error.Application, error.Host, error.Type, error.Source, error.Message, error.User, error.StatusCode, error.TimeUtc }).ToList(); return View(errors); as it results in a 'requires a model of type IEnumerable' error. The following code of course works fine, but selects all the columns, some of which I'm simply not interested in: var errors = (from error in db.ELMAH_Error select error).ToList(); return View(errors); I'm brand spanking new to MVC2 + L2E, so maybe I'm just not thinking in the right mindset yet, but this seems counter-intuitive. Is there an easy way to select a limited number of columns, or is this just part of using an ORM?

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  • How to use a varying database?

    - by nimo
    I want to use a database which name is stored in a variable. How do I do this? I first thought this would work but it doesn't: exec('use '+@db) That will not change database context Suggestions anyone?

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  • Best way to update/insert into a table based on a remote table.

    - by martilyo
    I have two very large enterprise tables in an Oracle 10g database. One table keeps the historical information of the other table. The problem is, I'm getting to the point where the records are just too many that my insert update is taking too long and my session is getting killed by the governor. Here's a pseudocode of my update process: sqlsel := 'SELECT col1, col2, col3, sysdate FROM table2@remote_location dpi WHERE (col1, col2, col3) IN ( SELECT col1, col2, col3 FROM table2@remote_location MINUS SELECT DISTINCT col1, col2, col3 FROM table1 mpc WHERE facility = '''||load_facility||''' )'; EXECUTE IMMEDIATE sqlsel BULK COLLECT INTO table1; I've tried the MERGE statement: MERGE INTO table1 t1 USING ( SELECT col1, col2, col3 FROM table2@remote_location ) t2 ON ( t1.col1 = t2.col1 AND t1.col2 = t2.col2 AND t1.col3 = t2.col3 ) WHEN NOT MATCHED THEN INSERT (t1.col1, t1.col2, t1.col3, t1.update_dttm ) VALUES (t2.col1, t2.col2, t2.col3, sysdate ) But there seems to be a confirmed bug on versions prior to Oracle 10.2.0.4 on the merge statement when doing a merge using a remote database. The chance of getting an enterprise upgrade is slim so is there a way to further optimize my first query or write it in another way to have it run best performance wise? Thanks.

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  • MySQL: Select pages that are not tagged?

    - by lauthiamkok
    Hi, I have a db with two tables like these below, page table pg_id title 1 a 2 b 3 c 4 d tagged table tagged_id pg_id 1 1 2 4 I want to select the pages which are tagged, I tried with this query below but doesn't work, SELECT * FROM root_pages LEFT JOIN root_tagged ON ( root_tagged.pg_id = root_pages.pg_id ) WHERE root_pages.pg_id != root_tagged.pg_id It returns zero - Showing rows 0 - 1 (2 total, Query took 0.0021 sec) But I want it to return pg_id title 2 b 3 c My query must have been wrong?? How can I return the pages which are not tagged correctly? Thanks.

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  • MySQL SELECT WHERE returning empty with long numbers, although they are there

    - by brybam
    Alright, so basically the most simple query ever... I've done this a million times... SELECT * FROM purchased_items WHERE uid = '$uid' if $uid == 123 It works fine and returns all data in rows where uid is 123 if $uid == 351565051447743 It returns empty... I'm positive 351565051447743 is a possible uid in some rows, i literally copied and pasted it into the table. $uid is a string, and is being passed as a string. This is something i've done a million times, and i've never had this simple query not work. Any ideas why this is not working?

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  • Load Empty Database table

    - by john White
    I am using SQLexpress and VS2008. I have a DB with a table named "A", which has an IdentitySpecification column named ID. The ID is auto-incremented. Even if the row is deleted, the ID still increases. After several data manipulation, the current ID has reached 15, for example. When I run the application if there's at least 1 row: if I add a new row, the new ID is 16. Everything is fine. If the table is empty (no row): if I add a new row, the new ID is 0, which is an error (I think). And further data manipulation (eg. delete or update) will result in an unhandled exception. Has anyone encountered this? PS. In my table definition, the ID has been selected as follow: Identity Increment = 1; Identity Seed =1; The DB load code is: dataSet = gcnew DataSet(); dataAdapter->Fill(dataSet,"A"); dataTable=dataSet->Tables["A"]; dbConnection->Open(); The Update button method dataAdapter->Update(dataSet,"tblInFlow"); dataSet->AcceptChanges(); dataTable=dataSet->Tables["tblInFlow"]; dataGrid->DataSource=dataTable; If I press Update: if there's at least a row: the datagrid view updates and shows the table correctly. if there's nothing in the table (no data row), the Add method will add a new row, but from ID 0. If I close the program and restart it again: the ID would be 16, which is correct. This is the add method row=dataTable->NewRow(); row["column1"]="something"; dataTable->Rows->Add(row); dataAdapter->Update(dataSet,"A"); dataSet->AcceptChanges(); dataTable=dataSet->Tables["A"];

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  • How to check if an entityset is populated

    - by TheQ
    How can i check if an entityset of a linq-object is populated or not? Example code below. My model have two methods, one joins data, and the other does not: public static Member GetMemberWithSettings(Guid memberId) { using (DataContext db = new DataContext()) { DataLoadOptions dataLoadOptions = new DataLoadOptions(); dataLoadOptions.LoadWith<Member>(x => x.Settings); db.LoadOptions = dataLoadOptions; var query = from x in db.Members where x.MemberId == memberId select x; return query.FirstOrDefault(); } } public static Member GetMember(Guid memberId) { using (DataContext db = new DataContext()) { var query = from x in db.Members where x.MemberId == memberId select x; return query.FirstOrDefault(); } } Then my control have the following code: Member member1 = Member.GetMemberWithSettings(memberId); Member member2 = Member.GetMember(memberId); Debug.WriteLine(member1.Settings.Count); Debug.WriteLine(member2.Settings.Count); The last line will generate a "Cannot access a disposed object" exception. I know that i can get rid of that exception just by not disposing the datacontext, but then the last line will generate a new query to the database, and i don't want that. What i would like is something like: Debug.WriteLine((member1.Settings.IsPopulated()) ? member1.Settings.Count : -1); Debug.WriteLine((member2.Settings.IsPopulated()) ? member2.Settings.Count : -1); Is it possible?

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