Search Results

Search found 4788 results on 192 pages for 'adhoc queries'.

Page 122/192 | < Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >

• How can I enable MySQL's slow query log without restarting MySQL?

  - by mmattax

  I followed the instructions here: http://crazytoon.com/2007/07/23/mysql-changing-runtime-variables-with-out-restarting-mysql-server/ but that seems to only set the threshold. Do I need to do anything else like set the filepath? According to MySQL's docs If no file_name value is given for --log-slow-queries, the default name is host_name-slow.log. The server creates the file in the data directory unless an absolute path name is given to specify a different directory. Running SHOW VARIABLES doesn't indicate any log file path and I don't see any slow query log file on my server...

  Read the article

• Find all clauses related to an atom

  - by Luc Touraille

  This is probably a very silly question (I just started learning Prolog a few hours ago), but is it possible to find all the clauses related to an atom? For example, assuming the following knowledge base: cat(tom). animal(X) :- cat(X). , is there a way to obtain every possible information about tom (or at least all the facts that are explicitly stated in the base)? I understand that a query like this is not possible: ?- Pred(tom). so I thought I could write a rule that would deduce the correct information: meta(Object, Predicate) :- Goal =.. [Predicate, Object], call(Goal). so that I could write queries such as ?- meta(tom, Predicate). but this does not work because arguments to call are not sufficiently instantiated. So basically my question is: is this at all possible, or is Prolog not design to provide this kind of information? And if it is not possible, why?

  Read the article

• Access DoCmd.OpenForm Not Working

  - by user961743

  Looking for a second set of eyes to figure out my problem with an Access form filter. I created a search form, when filled in, appends search criteria to a string variable (strQuery) that is put in place to the [WhereCondition] for opening a form. However, when the script is ran, nothing comes up except for a filtered form with no records. Here is the line that opens the form: DoCmd.OpenForm "ADD_NEW_NCMR", , , strQuery Before the line is ran, strQuery equals: 1=1 AND [NCMR].[NCMR_NUM] = '12-129' The form name, and table.column combination are all correct. In fact, using the DCount function returns the result of 1, which is correct for this query, and returns the correct number for other queries as well. This makes me think that there is nothing wrong with the where condition. DCount("[NCMR_NUM]", "NCMR", strQuery)

  Read the article

• Looking for a generic handler/service for mongodb and asp.net / c#

  - by JohnAgan

  I am new to MongoDB and have a perfect place in mind to use it. However, it's only worth it if I can make the queries from JavaScript and return JSON. I read another post on here of someone asking a similar question, but not specific to C#. What's the easiest way I can implement a generic service/handler in asp.net/c# that would allow me to interact with mongodb via JavaScript? I understand JavaScript can't call mongodb directly, so the next best thing is what I'm looking for.

  Read the article

• Help me understand Rails eager loading

  - by aaronrussell

  I'm a little confused as to the mechanics of eager loading in active record. Lets say a Book model has many Pages and I fetch a book using this query: @book = Book.find book_id, :include => :pages Now this where I'm confused. My understanding is that @book.pages is already loaded and won't execute another query. But suppose I want to find a specific page, what would I do? @book.pages.find page_id # OR... @book.pages.to_ary.find{|p| p.id == page_id} Am I right in thinking that the first example will execute another query, and therefore making the eager loading pointless, or is active record clever enough to know that it doesn't need to do another query? Also, my second question, is there an argument that in some cases eager loading is more intensive on the database and sometimes multiple small queries will be more efficient that a single large query? Thanks for your thoughts.

  Read the article

• MySQL: Count two things in one query?

  - by Nebs

  I have a "boolean" column in one of my tables (value is either 0 or 1). I need to get two counts: The number of rows that have the boolean set to 0 and the number of rows that have it set to 1. Currently I have two queries: One to count the 1's and the other to count the 0's. Is MySQL traversing the entire table when counting rows with a WHERE condition? I'm wondering if there's a single query that would allow two counters based on different conditions? Or is there a way to get the total count along side the WHERE conditioned count? This would be enough as I'd only have to subtract one count from the other (due to the boolean nature of the column). There are no NULL values. Thanks.

  Read the article

• Catching constraint violations in JPA 2.0.

  - by Dennetik

  Consider the following entity class, used with, for example, EclipseLink 2.0.2 - where the link attribute is not the primary key, but unique nontheless. @Entity public class Profile { @Id private Long id; @Column(unique = true) private String link; // Some more attributes and getter and setter methods } When I insert records with a duplicate value for the link attribute, EclipseLink does not throw a EntityExistsException, but throws a DatabaseException, with the message explaining that the unique constraint was violated. This doesn't seem very usefull, as there would not be a simple, database independent, way to catch this exception. What would be the advised way to deal with this? A few things that I have considered are: Checking the error code on the DatabaseException - I fear that this error code, though, is the native error code for the database; Checking the existence of a Profile with the specific value for link beforehand - this obviously would result in an enormous amount of superfluous queries.

  Read the article

• updating a table conditionally with values from a group by sub query in oracle

  - by user333147

  the problem is Update the salary of all the employees by 50% who had worked on 5 or more than 5 projects, by 30% (= 3 projects), by 20 % (= 1 projects) the number of project is got by performing a group by query on the EMPLOYEE_PROJECT_HISTORY; i have tried these queries 1) update emp set emp.sal= case when jemp.pcount >=5 then emp.sal+ (emp.sal*50)/100 when jemp.pcount >=3 then emp.sal+ (emp.sal*30)/100 when jemp.pcount >=1 then emp.sal+ (emp.sal*20)/100 else emp.sal+ (emp.sal*20)/100 end from employee emp join (select empno as jempno,count(projectno) as pcount from EMPLOYEE_PROJECT_HISTORY by empno) jemp on emp.empno=jemp.jempno ; 2)update employee a set a.sal= case (select count(b.projectno) as pcount from EMPLOYEE_PROJECT_HISTORY b group by b.empno ) when b.pcount >5 then a.sal = a.sal+ (a.sal*50)/100 when pcount >3 then a.sal = a.sal+ (a.sal*30)/100 when pcount >1 then a.sal = a.sal+ (a.sal*20)/100 end;

  Read the article

• How does mysql define DISTINCT()

  - by goran

  AFAIK SQL defines two uses of DISTINCT keywords - SELECT DISTINCT field... and SELECT COUNT(DISTINCT field) ... However in one of web applications that I administer I've noticed performance issues on queries like SELECT DISTINCT(field1), field2, field3 ... DISTINCT() on a single column makes no sense and I am almost sure it is interpreted as SELECT DISTINCT field1, field2, field3 ... but how can I prove this? I've searched mysql site for a reference on this particular syntax but could not find any. Does anyone have a link to definition of DISTINCT() in mysql or knows about other authoritative source on this? Best

  Read the article

• How do I display a field's hidden characters in the result of a query in Oracle?

  - by Chris Williams

  I have two rows that have a varchar column that are different according to a Java .equals(). I can't easily change or debug the Java code that's running against this particular database but I do have access to do queries directly against the database using SQLDeveloper. The fields look the same to me (they are street addresses with two lines separated by some new line or carriage feed/new line combo). Is there a way to see all of the hidden characters as the result of a query?I'd like to avoid having to use the ascii() function with substr() on each of the rows to figure out which hidden character is different. I'd also accept some query that shows me which character is the first difference between the two fields.

  Read the article

• CakePHP: How do I order results based on a 2-level deep association model?

  - by KcYxA

  I'm hoping I won't need to resort to custom queries. A related question would be: how do I retrieve data so that if an associated model is empty, no record is retrieved at all, as opposed to an empty array for an associated model? As an oversimplified example, say I have the following models: City -- Street -- House How do I sort City results by House numbers? How do I retrieve City restuls that have at least one House in it? I don't want a record with a city name and details and an empty House array as it messes up pagination results. CakePHP retrieves House records belonging to the Street in a separate query, so putting somthing like 'House.number DESC' into the 'order' field of the search query returns a 'field does not exist' error. Any ideas?

  Read the article

• How to deal with databases for websites written in Java, more specifically Wicket?

  - by John

  Hi there. I'm new to website development using Java but I've got started with Wicket and make a little website. I'd like to expand on what I've already made (a website with a form, labels and links) and implement database connectivity. I've looked at a couple of examples, in example Mystic Paste, and I see that they're using Hibernate and Spring. I've never touched Hibernate or Spring before and to be honest the heavy use of annotations scare me a little bit as I haven't really made use of them before, with the exception of supressing warnings and overriding. At this point I have one Connection object which I set up in the WebApplication class upon initialization. I then retrieve this connection object whenever I need to perform queries. I don't know if this is a bad approach or not for a production web application. All help is greatly appreciated.

  Read the article

• Soql query to get all related contacts of an account in an opportunity

  - by Prady

  i have SOQL query which queries for some records based on a where condition. select id, name,account.name ... <other fields> from opportunity where eventname__c='Test Event' i also need to get the related contact details for the account in the opportunity. ie i need to add the email ids of contact who all are part of the account in the opportunity. For each opportunity, i need to get all the contacts emailids who are associated with the account in opportunity. I cant really figure out how to approach this. referring the documentation i can get the contact info of a account using the query SELECT Name, ( SELECT LastName FROM Contacts ) FROM Account How can i use this along with opportunity? Thanks

  Read the article

• Mysqld Crashes immediately on running on Windows 7...?

  - by Cyril Gupta

  I am trying to run MySql 5.1 on Windows 7 Home Premium 64 bit. I have downloaded the MSI installer from the MYSql website and installed it. The installation is successful, but the service does not start. If I try to run MySql manually using the mysqld executable, it crashes immediately on running (error: mysqld.exe has stopped working). Earlier mysql was running on the machine, but I had some problem with it (wasn't executing big queries) and installed it again which somehow broke the program. I had installed it to work as a service which started giving me this isse, and now it won't work even if I don't install it as a service. I have tried removing the mysql folder and re-installing. Is there somewhere else where Mysql saves configuration info or other data? Has anyone else found this problem and solved it? How can I find out why the process is failing to run?

  Read the article

• nth smallest number among two databases of size n each using divide and conquer

  - by urfriend

  we have two databases of size n containing numbers without repeats. So, in total we have 2n elements. They can be accessed through a query to one database at a time. The query is such that you give it a k and it returns kth smallest entry in that database. we need to find nth smallest entry among all the 2n elements in O(logn) queries. the idea is to use divide and conquer but i need some help thinking through this. thanks!

  Read the article

• Reversing column values in mysql command line

  - by user94154

  I have a table posts with the column published, which is either 0 (unpublished) or 1 (published). Say I want to make all the published posts into unpublished posts and all the unpublished posts into published posts. I know that running UPDATE posts SET published = 1 WHERE published = 0; UPDATE posts SET published = 0 WHERE published = 1; will end up turning all my posts into published posts. How can I run these queries in the mysql command line so that it truly "reverse" the values, as opposed to the mistake outlined above? Thanks

  Read the article

• Query DNSBL or other block lists using PHP

  - by 55skidoo

  Is there any way to use PHP code to query a DNSBL (block list) provider and find out if the IP address submitted is a bad actor? I would like to take an existing IP address out of a registration database, then check whether it's a known block-listed IP address by performing a lookup on it, then if it's a blacklisted, do an action on it (such as, delete entry from registration database). Most of the instructions I have seen assume you are trying to query the blocklist via a mail server, which I can't do. I tried querying via web browser by typing in queries such as "58.64.xx.xxx.dnsbl.sorbs.net" but that didn't work.

  Read the article

• PDO update query with conditional?

  - by dmontain

  I have a PDO mysql that updates 3 fields. $update = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2, field3=:field3 WHERE key=:key"); But I want field3 to be updated only when $update3 = true; (meaning that the update of field3 is controlled by a conditional statement) Is this possible to accomplish with a single query? I could do it with 2 queries where I update field1 and field2 then check the boolean and update field3 if needed in a separate query. //run this query to update only fields 1 and 2 $update_part1 = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2 WHERE key=:key"); //if field3 should be update, run a separate query to update it separately if ($update3){ $update_part2 = $mypdo->prepare("UPDATE tablename SET field3=:field3 WHERE key=:key"); } But hopefully there is a way to accomplish this in 1 query?

  Read the article

• Does the optimizer filter subqueries with outer where clauses

  - by Mongus Pong

  Take the following query: select * from ( select a, b from c UNION select a, b from d ) where a = 'mung' Will the optimizer generally work out that I am filtering a on the value 'mung' and consequently filter mung on each of the queries in the subquery. OR will it run each query within the subquery union and return the results to the outer query for filtering (as the query would perhaps suggest) In which case the following query would perform better : select * from ( select a, b from c where a = 'mung' UNION select a, b from d where a = 'mung' ) Obviously query 1 is best for maintenance, but is it sacrificing much performace for this? Which is best?

  Read the article

• Seeking a GUI auto-format feature for T-SQL

  - by dvanaria

  Is there a freely available GUI tool that will allow interaction with Microsoft SQL Server (via T-SQL) that provides an auto-format feature? I constantly find myself writing queries in SQL Query Analyzer (Microsoft’s standard GUI tool for T-SQL) and cutting/pasting the whole thing into SQLyog (a GUI tool for MySQL), where I can press F12 and have it reformatted into an easily readable, industry standard format. I then cut/paste this back into Query Analyzer to execute. I do this all the time at work and haven’t been able to find an alternative. I realize that SQLyog is no longer free software, but what I’m looking for is a specific alternative to a MS SQL Server interface (with auto-formatting). Thanks in advance for your help.

  Read the article

• search engine crawling frequency

  - by Aditya Pratap Singh

  I want to design a search engine for news websites ie. download various article pages from these websites, index the pages, and answer search queries on the index. I want a short pseudocode to find an appropriate crawling frequency -- i do not want to crawl too often because the website may not have changed, and do not want to crawl too infrequently because index would then be out of date. Assume that crawling code looks as follows while(1) { sleep(sleep_interval); // sleep for sleep_interval crawl(website); // crawls the entire website diff = diff(currently_crawled_website, previously_crawled_website); // returns a % value of difference between the latest and previous crawls of the website sleep_interval = infer_sleep_interval(diff, sleep_interval); } looking for a pseudocode for the infer_sleep_interval method: long sleep_interval infer_sleep_interval(int diff_percentage,long previous_sleep_interval) { ... ... ... } i want to design method which adaptively alters the sleeping interval based on the update frequency of the website.

  Read the article

• Given GPS coordinates, how do I find nearby landmarks or points-of-interest?

  - by stackoverflowuser2010

  I just bought a Google Nexus One smartphone, and I want to write a small Android application for fun. Suppose I can get my current GPS coordinates, so then how can I programmatically find nearby landmarks or points-of-interest within some radius? Is there an API to get GPS geo-tagged landmarks, like in Google Earth's database? For example, if I'm in downtown Chicago, my program would point me to all the "tourist" things to visit in that city. Ideally, it would all run on my smartphone, but if necessary, I can have the smartphone query a webserver, which would then run more queries.

  Read the article

• Safe HttpContext.Current.Cache Usage

  - by Burak SARICA

  Hello there, I use Cache in a web service method like this : var pblDataList = (List<blabla>)HttpContext.Current.Cache.Get("pblDataList"); if (pblDataList == null) { var PBLData = dc.ExecuteQuery<blabla>( @"SELECT blabla"); pblDataList = PBLData.ToList(); HttpContext.Current.Cache.Add("pblDataList", pblDataList, null, DateTime.Now.Add(new TimeSpan(0, 0, 15)), Cache.NoSlidingExpiration, CacheItemPriority.Normal, null); } I wonder is it thread safe? I mean the method is called by multiple requesters And more then one requester may hit the second line at the same time while the cache is empty. So all of these requesters will retrieve the data and add to cache. The query takes 5-8 seconds. May a surrounding lock statement around this code prevent that action? (I know multiple queries will not cause error but i want to be sure running just one query.)

  Read the article

• make multiple, composite query in oracle

  - by Meloun

  How can i make multiple, composite query in oracle? for example this several queries in one step? 1 CREATE TABLE test (id NUMBER PRIMARY KEY, name VARCHAR2(30)); 2 CREATE SEQUENCE test_sequence START WITH 1 INCREMENT BY 1; 3 CREATE OR REPLACE TRIGGER test_trigger BEFORE INSERT ON test REFERENCING NEW AS NEW FOR EACH ROW BEGIN SELECT test_sequence.nextval INTO :NEW.ID FROM dual; END; 4 INSERT INTO test (name) VALUES ('Jon'); 5 INSERT INTO test (name) VALUES ('Meloun');

  Read the article

• How can I limit the number of connections to an mssql server from my tomcat deployed java applicatio

  - by CJ

  Hi, I have an application that is deployed on tomcat on server A and sends queries to a huge variety of mssql databases on an server B. I am concerned that my application could overload this mssql database server and would like some way to preventing it making requests to connect to any database on that server if some arbitrary number of connections were already in existence and unclosed. I am looking at using connection pooling but am under the impression that this will only pool connections to a specific database on the mssql server, I want to control the total of these combined connections that will occur to many different databases (incidentally I can only find out the names of individual db's dynamically as they change day to day). Will connection pooling take care of this for me, are am I looking at this from the wrong perspective? I have no access to the configuration of the mssql server. Links to tutorials or working examples of your suggested solution are most welcome! Thanks, Caroline

  Read the article

< Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >