Search Results

Search found 6311 results on 253 pages for 'limit clause'.

Page 88/253 | < Previous Page | 84 85 86 87 88 89 90 91 92 93 94 95  | Next Page >

• Problem trying to achieve a join using the `comments` contrib in Django

  - by NiKo

  Hi, Django rookie here. I have this model, comments are managed with the django_comments contrib: class Fortune(models.Model): author = models.CharField(max_length=45, blank=False) title = models.CharField(max_length=200, blank=False) slug = models.SlugField(_('slug'), db_index=True, max_length=255, unique_for_date='pub_date') content = models.TextField(blank=False) pub_date = models.DateTimeField(_('published date'), db_index=True, default=datetime.now()) votes = models.IntegerField(default=0) comments = generic.GenericRelation( Comment, content_type_field='content_type', object_id_field='object_pk' ) I want to retrieve Fortune objects with a supplementary nb_comments value for each, counting their respectve number of comments ; I try this query: >>> Fortune.objects.annotate(nb_comments=models.Count('comments')) From the shell: >>> from django_fortunes.models import Fortune >>> from django.db.models import Count >>> Fortune.objects.annotate(nb_comments=Count('comments')) [<Fortune: My first fortune, from NiKo>, <Fortune: Another One, from Dude>, <Fortune: A funny one, from NiKo>] >>> from django.db import connection >>> connection.queries.pop() {'time': '0.000', 'sql': u'SELECT "django_fortunes_fortune"."id", "django_fortunes_fortune"."author", "django_fortunes_fortune"."title", "django_fortunes_fortune"."slug", "django_fortunes_fortune"."content", "django_fortunes_fortune"."pub_date", "django_fortunes_fortune"."votes", COUNT("django_comments"."id") AS "nb_comments" FROM "django_fortunes_fortune" LEFT OUTER JOIN "django_comments" ON ("django_fortunes_fortune"."id" = "django_comments"."object_pk") GROUP BY "django_fortunes_fortune"."id", "django_fortunes_fortune"."author", "django_fortunes_fortune"."title", "django_fortunes_fortune"."slug", "django_fortunes_fortune"."content", "django_fortunes_fortune"."pub_date", "django_fortunes_fortune"."votes" LIMIT 21'} Below is the properly formatted sql query: SELECT "django_fortunes_fortune"."id", "django_fortunes_fortune"."author", "django_fortunes_fortune"."title", "django_fortunes_fortune"."slug", "django_fortunes_fortune"."content", "django_fortunes_fortune"."pub_date", "django_fortunes_fortune"."votes", COUNT("django_comments"."id") AS "nb_comments" FROM "django_fortunes_fortune" LEFT OUTER JOIN "django_comments" ON ("django_fortunes_fortune"."id" = "django_comments"."object_pk") GROUP BY "django_fortunes_fortune"."id", "django_fortunes_fortune"."author", "django_fortunes_fortune"."title", "django_fortunes_fortune"."slug", "django_fortunes_fortune"."content", "django_fortunes_fortune"."pub_date", "django_fortunes_fortune"."votes" LIMIT 21 Can you spot the problem? Django won't LEFT JOIN the django_comments table with the content_type data (which contains a reference to the fortune one). This is the kind of query I'd like to be able to generate using the ORM: SELECT "django_fortunes_fortune"."id", "django_fortunes_fortune"."author", "django_fortunes_fortune"."title", COUNT("django_comments"."id") AS "nb_comments" FROM "django_fortunes_fortune" LEFT OUTER JOIN "django_comments" ON ("django_fortunes_fortune"."id" = "django_comments"."object_pk") LEFT OUTER JOIN "django_content_type" ON ("django_comments"."content_type_id" = "django_content_type"."id") GROUP BY "django_fortunes_fortune"."id", "django_fortunes_fortune"."author", "django_fortunes_fortune"."title", "django_fortunes_fortune"."slug", "django_fortunes_fortune"."content", "django_fortunes_fortune"."pub_date", "django_fortunes_fortune"."votes" LIMIT 21 But I don't manage to do it, so help from Django veterans would be much appreciated :) Hint: I'm using Django 1.2-DEV Thanks in advance for your help.

  Read the article

• rm on a directory with millions of files

  - by BMDan

  Background: physical server, about two years old, 7200-RPM SATA drives connected to a 3Ware RAID card, ext3 FS mounted noatime and data=ordered, not under crazy load, kernel 2.6.18-92.1.22.el5, uptime 545 days. Directory doesn't contain any subdirectories, just millions of small (~100 byte) files, with some larger (a few KB) ones. We have a server that has gone a bit cuckoo over the course of the last few months, but we only noticed it the other day when it started being unable to write to a directory due to it containing too many files. Specifically, it started throwing this error in /var/log/messages: ext3_dx_add_entry: Directory index full! The disk in question has plenty of inodes remaining: Filesystem Inodes IUsed IFree IUse% Mounted on /dev/sda3 60719104 3465660 57253444 6% / So I'm guessing that means we hit the limit of how many entries can be in the directory file itself. No idea how many files that would be, but it can't be more, as you can see, than three million or so. Not that that's good, mind you! But that's part one of my question: exactly what is that upper limit? Is it tunable? Before I get yelled at--I want to tune it down; this enormous directory caused all sorts of issues. Anyway, we tracked down the issue in the code that was generating all of those files, and we've corrected it. Now I'm stuck with deleting the directory. A few options here: rm -rf (dir)I tried this first. I gave up and killed it after it had run for a day and a half without any discernible impact. unlink(2) on the directory: Definitely worth consideration, but the question is whether it'd be faster to delete the files inside the directory via fsck than to delete via unlink(2). That is, one way or another, I've got to mark those inodes as unused. This assumes, of course, that I can tell fsck not to drop entries to the files in /lost+found; otherwise, I've just moved my problem. In addition to all the other concerns, after reading about this a bit more, it turns out I'd probably have to call some internal FS functions, as none of the unlink(2) variants I can find would allow me to just blithely delete a directory with entries in it. Pooh. while [ true ]; do ls -Uf | head -n 10000 | xargs rm -f 2/dev/null; done ) This is actually the shortened version; the real one I'm running, which just adds some progress-reporting and a clean stop when we run out of files to delete, is: export i=0; time ( while [ true ]; do ls -Uf | head -n 3 | grep -qF '.png' || break; ls -Uf | head -n 10000 | xargs rm -f 2/dev/null; export i=$(($i+10000)); echo "$i..."; done ) This seems to be working rather well. As I write this, it's deleted 260,000 files in the past thirty minutes or so. Now, for the questions: As mentioned above, is the per-directory entry limit tunable? Why did it take "real 7m9.561s / user 0m0.001s / sys 0m0.001s" to delete a single file which was the first one in the list returned by "ls -U", and it took perhaps ten minutes to delete the first 10,000 entries with the command in #3, but now it's hauling along quite happily? For that matter, it deleted 260,000 in about thirty minutes, but it's now taken another fifteen minutes to delete 60,000 more. Why the huge swings in speed? Is there a better way to do this sort of thing? Not store millions of files in a directory; I know that's silly, and it wouldn't have happened on my watch. Googling the problem and looking through SF and SO offers a lot of variations on "find" that obviously have the wrong idea; it's not going to be faster than my approach for several self-evident reasons. But does the delete-via-fsck idea have any legs? Or something else entirely? I'm eager to hear out-of-the-box (or inside-the-not-well-known-box) thinking. Thanks for reading the small novel; feel free to ask questions and I'll be sure to respond. I'll also update the question with the final number of files and how long the delete script ran once I have that. Final script output!: 2970000... 2980000... 2990000... 3000000... 3010000... real 253m59.331s user 0m6.061s sys 5m4.019s So, three million files deleted in a bit over four hours.

  Read the article

• INSERT OR IGNORE in a trigger

  - by dan04

  I have a database (for tracking email statistics) that has grown to hundreds of megabytes, and I've been looking for ways to reduce it. It seems that the main reason for the large file size is that the same strings tend to be repeated in thousands of rows. To avoid this problem, I plan to create another table for a string pool, like so: CREATE TABLE AddressLookup ( ID INTEGER PRIMARY KEY AUTOINCREMENT, Address TEXT UNIQUE ); CREATE TABLE EmailInfo ( MessageID INTEGER PRIMARY KEY AUTOINCREMENT, ToAddrRef INTEGER REFERENCES AddressLookup(ID), FromAddrRef INTEGER REFERENCES AddressLookup(ID) /* Additional columns omitted for brevity. */ ); And for convenience, a view to join these tables: CREATE VIEW EmailView AS SELECT MessageID, A1.Address AS ToAddr, A2.Address AS FromAddr FROM EmailInfo LEFT JOIN AddressLookup A1 ON (ToAddrRef = A1.ID) LEFT JOIN AddressLookup A2 ON (FromAddrRef = A2.ID); In order to be able to use this view as if it were a regular table, I've made some triggers: CREATE TRIGGER trg_id_EmailView INSTEAD OF DELETE ON EmailView BEGIN DELETE FROM EmailInfo WHERE MessageID = OLD.MessageID; END; CREATE TRIGGER trg_ii_EmailView INSTEAD OF INSERT ON EmailView BEGIN INSERT OR IGNORE INTO AddressLookup(Address) VALUES (NEW.ToAddr); INSERT OR IGNORE INTO AddressLookup(Address) VALUES (NEW.FromAddr); INSERT INTO EmailInfo SELECT NEW.MessageID, A1.ID, A2.ID FROM AddressLookup A1, AddressLookup A2 WHERE A1.Address = NEW.ToAddr AND A2.Address = NEW.FromAddr; END; CREATE TRIGGER trg_iu_EmailView INSTEAD OF UPDATE ON EmailView BEGIN UPDATE EmailInfo SET MessageID = NEW.MessageID WHERE MessageID = OLD.MessageID; REPLACE INTO EmailView SELECT NEW.MessageID, NEW.ToAddr, NEW.FromAddr; END; The problem After: INSERT OR REPLACE INTO EmailView VALUES (1, '[email protected]', '[email protected]'); INSERT OR REPLACE INTO EmailView VALUES (2, '[email protected]', '[email protected]'); The updated rows contain: MessageID ToAddr FromAddr --------- ------ -------- 1 NULL [email protected] 2 [email protected] [email protected] There's a NULL that shouldn't be there. The corresponding cell in the EmailInfo table contains an orphaned ToAddrRef value. If you do the INSERTs one at a time, you'll see that Alice's ID in the AddressLookup table changes! It appears that this behavior is documented: An ON CONFLICT clause may be specified as part of an UPDATE or INSERT action within the body of the trigger. However if an ON CONFLICT clause is specified as part of the statement causing the trigger to fire, then conflict handling policy of the outer statement is used instead. So the "REPLACE" in the top-level "INSERT OR REPLACE" statement is overriding the critical "INSERT OR IGNORE" in the trigger program. Is there a way I can make it work the way that I wanted?

  Read the article

• problem with a join

  - by Luca Romagnoli

  I have this code: int se = (int) settings.GruppoSegreteria; var acc = db.USR_Accounts.Where( p => p.ID_Gruppo == se); var segreterie = from s in db.USR_Utenti join h in acc on s.ID equals h.USR_UtentiReference select s; And this error: The type of one of the expressions in the join clause is incorrect. Type inference failed in the call to 'Join' I don't understand it. Can you help me? thanks

  Read the article

• data structure algorithms for database searching

  - by Ygam

  I was used to the traditional way of doing database searching with the following using wildcards for term searches using where clause for specific data like addresses and names but at other times, I found these common methods to produce code that is so bloated, especially when it comes to complex searches. Are there algorithms out there that you use for complex database searching? I tried to look for some but had a hard time doing so. I stumbled accross the binary search but I can't find a use for it :(

  Read the article

• how does a sql query work?

  - by Anand

  Hi, How does a sql query work ? how does it get compiled ? Is the from clause complied first to see if the table exists ? How does it actually retrieve data from the database ? How and in what format are the tables stored in a database ? I am using phpmyadmin is there anyway I can peek into the files where data is stored ??

  Read the article

• Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?

  - by ctrlShiftBryan

  Using MSSQL2005, Can I truncate a table with a foreign key constraint if I first truncate the child table(the table with the primary key of the FK relationship)? I know I can use a DELETE without a where clause and then RESEED the identity OR Remove the FK, truncate and recreate but I thought as long as you truncate the child table you'll be OK however I'm getting a "Cannot truncate table 'TableName' because it is being referenced by a FOREIGN KEY constraint." error.

  Read the article

• Zend_DB_Table Update problem

  - by davykiash

  Am trying to construct a simple update query in my model class Model_DbTable_Account extends Zend_Db_Table_Abstract { protected $_name = 'accounts'; public function activateaccount($activationcode) { $data = array( 'accounts_status' => 'active', ); $this->update($data, 'accounts_activationkey = ' . $activationcode); } However I get an SQLSTATE[42S22]: Column not found: 1054 Unknown column 'my activation code value' in 'where clause' error. What am I missing in Zend_Table update construct?

  Read the article

• I get an error when implementing tde in SQL Server 2008

  - by mahima

  While using USE mssqltips_tde; CREATE DATABASE ENCRYPTION KEY with ALGORITHM = AES_256 ENCRYPTION BY SERVER CERTIFICATE TDECert GO I'm getting an 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

  Read the article

• Purpose of Explicit Default Constructors

  - by Dennis Zickefoose

  I recently noticed a class in C++0x that calls for an explicit default constructor. However, I'm failing to come up with a scenario in which a default constructor can be called implicitly. It seems like a rather pointless specifier. I thought maybe it would disallow Class c; in favor of Class c = Class(); but that does not appear to be the case. Some relevant quotes from the C++0x FCD, since it is easier for me to navigate [similar text exists in C++03, if not in the same places] 12.3.1.3 [class.conv.ctor] A default constructor may be an explicit constructor; such a constructor will be used to perform default-initialization or value initialization (8.5). It goes on to provide an example of an explicit default constructor, but it simply mimics the example I provided above. 8.5.6 [decl.init] To default-initialize an object of type T means: — if T is a (possibly cv-qualified) class type (Clause 9), the default constructor for T is called (and the initialization is ill-formed if T has no accessible default constructor); 8.5.7 [decl.init] To value-initialize an object of type T means: — if T is a (possibly cv-qualified) class type (Clause 9) with a user-provided constructor (12.1), then the default constructor for T is called (and the initialization is ill-formed if T has no accessible default constructor); In both cases, the standard calls for the default constructor to be called. But that is what would happen if the default constructor were non-explicit. For completeness sake: 8.5.11 [decl.init] If no initializer is specified for an object, the object is default-initialized; From what I can tell, this just leaves conversion from no data. Which doesn't make sense. The best I can come up with would be the following: void function(Class c); int main() { function(); //implicitly convert from no parameter to a single parameter } But obviously that isn't the way C++ handles default arguments. What else is there that would make explicit Class(); behave differently from Class();? The specific example that generated this question was std::function [20.8.14.2 func.wrap.func]. It requires several converting constructors, none of which are marked explicit, but the default constructor is.

  Read the article

• how to delete all the data from the table in sqlplus oracle

  - by Nubkadiya

  i want to delete all the data rows in the table. but without dropping the table. delete statement has a where clause so i have to give one by one for each row. is there any other way of deleting the whole data rows in the table. this is Oracle and using sqlplus

  Read the article

• MySQL column not found

  - by vian

  The SQL query without where statement runs great and outputs good results, but when I include WHERE condition it shows Unknown column 'date1' in 'where clause'. What's the problem? SELECT IF(e.weekly, DATE_ADD(DATE(e.time), INTERVAL CEIL(DATEDIFF('2010-04-08', e.time)/7) WEEK), DATE(e.time)) AS `e.date1`, `v`.`lat`, `v`.`lng` FROM `events` AS `e` INNER JOIN `venues` AS `v` ON e.venue_id = v.id WHERE e.date1 > '2010-09-01'

  Read the article

• Using .net Datetime in sql query

  - by Patrick

  I have a DateTime object I want to compare against an sql datetime field in a where clause. I'm currently using: "where (convert( dateTime, '" & datetimeVariable.ToString & "',103) <= DatetimeField)" But I believe datetimeVariable.ToString will return a different value depending on the culture where the system is running. How would you handle this so it is culture independent?

  Read the article

• How can one extract rdf:about or rdf:ID properties from triples using SPARQL?

  - by lennyks

  It seemed a trivial matter at the beginning but so far I have not managed to get the unique identifier for a given resource using SPARQL. What I mean is given, e.g., rdf:Description rdf:about="http://..." and then some properties identifying this resource, what I want to do is to first find this very resource and then retrieve all the triples given some URI. I have tried naïve approaches by writing statements in a WHERE clause such as: ?x rdf:about ?y and ?x rdfs:about ?y I hope I am being precise.

  Read the article

• delete last row in a table android

  - by Sephy

  Hi everybody, My question is quite straightforward. I have a table, with, lets say x rows, with each an id, but i don't know how many rows i have. Now i want to delete the last row of my table for some reason... Is there an easy way to do that in android? I have been trying to use the last_insert_rowid in my where clause...but no luck so far... any idea? thx for help

  Read the article

• how to use the order by and aggregate function together in sql query

  - by Ranjana

  SELECT count(distinct req.requirementid), req.requirementid, org.organizationid,req. locationofposting,org.registereddate FROM OrganizationRegisteredDetails AS org, RequirementsDetailsforOrganization AS req WHERE org.organizationid =req.requirementid order by org.RegisteredDate desc this shows me the error : Column 'RequirementsDetailsforOrganization.RequirementID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. how to do the 'order by org.RegisteredDate desc' in this Query ....

  Read the article

• Why use infinite loops?

  - by Moishe

  Another poster asked about preferred syntax for infinite loops. A follow-up question: Why do you use infinite loops in your code? I typically see a construct like this: for (;;) { int scoped_variable = getSomeValue(); if (scoped_variable == some_value) { break; } } Which lets you get around not being able to see the value of scoped_variable in the for or while clause. What are some other uses for "infinite" loops?

  Read the article

• In postgresql return result of a function in a rule when performing INSERT INTO RETURNING

  - by Dmitry

  I have a View that has several fields. When i INSERT INTO a view I run a function based on INSERT parametrs. The function returns a value. How can I retrieve The value from rule? INSERT RETURNING Gives me: ERROR: cannot perform INSERT RETURNING on relation "full_subntes" ?????????: You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.

  Read the article

• Selecting a column that is also a keyword in MySQL

  - by randall123

  For some reason, the developers at a new company I'm working for decided to name their columns "ignore" and "exists". Now when I run MySQL queries with those words in the where clause, I get a syntax error; however, I can't seem to figure out how to reference those columns without running into an error. I tried setting them as strings, but that doesn't make any sense. Help? Also, is there a term for this kind of mismatch?

  Read the article

• Can a database function be called in the predicate of a llblgen query?

  - by Dan Appleyard

  I want to use a table-valued database function in the where clause of a query I am building using LLBLGen Pro 2.6 (self-servicing). SELECT * FROM [dbo].[Users] WHERE [dbo].[Users].[UserID] IN ( SELECT UserID FROM [dbo].[GetScopedUsers] (@ScopedUserID) ) I am looking into the FieldCompareSetPredicate class, but can't for the life of me figure out what the exact signature would be. Any help would be greatly appreciated.

  Read the article

• Is there any boost-independent version of boost/tr1 shared_ptr

  - by Artyom

  I'm looking for independent implementation of boost/tr1 shared_ptr, weak_ptr and enable_shared_from_this. I need: Boost independent very small implementation of these features. I need support of only modern compilers like GCC-4.x, MSVC-2008, Intel not things like MSVC6 or gcc-3.3 I need it to be licensed under non-copyleft LGPL compatible license like Boost/Mit/3-clause BSD. So I can include it in my library. Note - it is quite hard to extract shared_ptr from boost, at least BCP gives about 324 files...

  Read the article

• mysql order-by original "where order"

  - by Benjamin Dobnikar

  I have this order-by problem I canot crack. I select from my table like this: SELECT * FROM 'sidemodules' WHERE name = 'module1' OR name = 'module2' OR 'name3' Which returns me the modules I want. But the modules lie the table, say in this order: module3 module1 module2 And they are returned to me in this order. How can I get them to display in order AS IN THE WHERE CLAUSE (1,2,3) ? Big thanks!

  Read the article

• SQl queries searching by date range

  - by tecno

  Hi, I have a table in an Access 2007 database, all fields are of type text. Can the following be done using the where clause. If so how? SELECT * from Table1 WHERE (ColumnDate is between 26th and 19th of march 2010) SELECT * from Table1 WHERE (ColumnAge is between 25 and 40) The usual < <= operators dont seem to work. Thanks,

  Read the article

• 'Contains()' workaround using Linq to Entities?

  - by jbloomer

  I'm trying to create a query which uses a list of ids in the where clause, using the Silverlight ADO.Net Data Services client api (and therefore Linq To Entities). Does anyone know of a workaround to Contains not being supported? I want to do something like this: List<long?> txnIds = new List<long?>(); // Fill list var q = from t in svc.OpenTransaction where txnIds.Contains(t.OpenTransactionId) select t;

  Read the article

• How can one extra rdf:about or rdf:ID properties from triples using SPARKQL?

  - by lennyks

  It seemed a trivial matter at the beginning but so far I had not managed to get unique identifier for a given resource using SPARKQL. What I mean is given and then some properties identifiying this resource in perfect world I want to first know how to retrieve an individual triple given some uri. I have tried naive approaches by writing statements in a WHERE clause such as ?x rdf:about ?y and ?x rdfs:about ?y. I hope I am being precise.

  Read the article

< Previous Page | 84 85 86 87 88 89 90 91 92 93 94 95  | Next Page >