limit

问题 Facing an issue of duplicate records while fetching record by sorting with skip and limit: Collection Data: { "_id" : ObjectId("594b507c9b9469ec9da6a78b"), "name" : "F", "percentage" : 60.0, "weightedFilter" : 2.0, "like" : 1.0, "attraction" : 1.0 } { "_id" : ObjectId("594b507c9b9469ec9da6a78c"), "name" : "I", "percentage" : 80.0, "weightedFilter" : 0.0, "like" : 1.0, "attraction" : 1.0 } { "_id" : ObjectId("594b507c9b9469ec9da6a78d"), "name" : "J", "percentage" : 80.0, "weightedFilter" : 1.0

问题 I have a table student(id, name, department, age, score). I want to find the youngest student who has the highest(among the youngest students) score of each department. In SQL Server, I can use following SQL. select * from student s1 where s1.id in (select s2.id from student s2 where s2.department = s1.department order by age asc, score desc top 1). However, in Oracle, you cannot use the order by clause in subquery and there is no limit/top like keyword. I have to join the student table with

问题 I was finally convinced to put my smaller tables into one large one, but exactly how big is too big for a MySQL table? I have a table with 18 fields. Some are TEXT , some are short VARCHAR(16) , others longer VARCHAR(100) . Right now we get about 200,000 rows a day, which would be 6 million+ a month. How big is too big? Does it matter how many fields you have, or just rows? 回答1: There's not a great general solution to the question "How big is too big" - such concerns are frequently dependent

问题 Is it possible to limit the number of rows that are updated using Hibernate/HQL? For instance: Query q = em.createQuery("UPDATE MyObj o Set o.prop = :prop"); q.setParameter("prop", "foo"); q.setMaxResults(myLimit); int res = q.executeUpdate(); if (res > myLimit) { // This is entering here and I don't want it to! } I've been Googling around and such, and I am trying to use HQL so that I can do some unit tests using HSQL DB in memory dbs, as well as using MySql in deployment. MySql supports the

问题 I want to add a security on a sensitive table when I delete lines with an SQL request on a DB2 table. I want to mimic the way MySQL allows you to limit the numbers of rows deleted in an SQL request. Basically I want to do this with DB2 : DELETE FROM table WHERE info = '1' LIMIT 1 Is there a way to do that with DB2 ? 回答1: delete from table where id in (select id from table where info = '1' order by id fetch first 1 rows only) 回答2: It really depends on your platform. If you're using DB2 on

问题 We are working on project at wavestack.com and we are dealing with an issue that its giving us a hard time. Our page is supposed to load many audio tags at the same time, from a streaming source. You can check the concept in the following link: http://wavestack.com/songs/nTNonwsCSg932CtzPLk1FA== The problem comes when we're trying to load more than 6 tracks at the same time, as shown in the following link: http://wavestack.com/songs/hp7G8CSsg45t3fV5YNeqbQ== This page is working well on

问题 I came across some Fortran 90 code where 68 arguments are passed to a function. Upon searching the web I only found something about a limit of passing 256 bytes for some CUDA Fortran related stuff (http://www.pgroup.com/userforum/viewtopic.php?t=2235&sid=f241ca3fd406ef89d0ba08a361acd962). So I wonder: is there a limit to the number of arguments that may be passed to a function for Intel/Visual/GNU fortran compilers? 回答1: I came across this discussion of the Fortran 90 standards: http://www

问题 Does anybody know how to disable or change the timeout limit for CUDA kernels under Ubuntu 12.10? (With current versions of Windows one can set the timeout limit in the registry.) Please tell me as well if there is no possibility to do this with Ubuntu. The only results of my previous search are the following: running the CUDA kernel without a graphical display is attached to the GPU splitting the kernel into smaller ones to avoid exceeding the time limit Both solutions are no option for me

问题 Does anybody know how to disable or change the timeout limit for CUDA kernels under Ubuntu 12.10? (With current versions of Windows one can set the timeout limit in the registry.) Please tell me as well if there is no possibility to do this with Ubuntu. The only results of my previous search are the following: running the CUDA kernel without a graphical display is attached to the GPU splitting the kernel into smaller ones to avoid exceeding the time limit Both solutions are no option for me

问题 I have a table in SQL, it contains around 100 rows. I select it within PHP with SELECT * FROM table . I didn't use offset nor limit. My question now is, is there are way to manipulate the returned result using only PHP to display only like 24 rows from the table? What should I try? 回答1: Well, I guess now that the oracle tag was added, I'll add the oracle answer. $rows = array(row, row, row, ...); // from oracle sql results $first_24_rows = array_slice($rows, 0, 24); 回答2: The general format