similar to: Creating queries..

Hi! I''m looking for a good tutorial that explains the main points of performing queries with Rails. I do have AWDWR and have read the section on ''find'' but I''m looking for something that goes into more detail on how to perform queries across tables. Abstracted from my current application, this is an example: * person has_many sites * site has_one room *

i have a table of data in my application. i would like to be able to sort the data in the table by clicking on the column header. the way i was thinking i want to do this is just by making a ''sort'' action, and then calling the sort action from each link in the table header (passing the respective column name). it doesn''t seem to be possible to pass parameters to an

Hi *, I have a few modules in lib/ and I use them mostly in my models. I''d like to add a few unit tests and run them with rake with all other tests of my app: where do I have to write them ? TIA, ngw -- Nicholas Wieland nicholas_wieland@yahoo.it -------------- next part -------------- An HTML attachment was scrubbed... URL:

I have a category list which the customer wants administratively to define the sort order, instead of alphabetical or whatever. The obvious approach seems to be to put a sort_order int on the record and use this as the presentation sort order. Then to shift the item up in the sort order to swap the current and the prevous item in the sort_order. Does this seem like a sensible approach, or is

I have an original_at column in my photos table. I''d like to get a list of distinct years that occur in this column, and some of the values are NULL. I see two ways of doing this. The SQLish way: photos = Photo.find :all, :select => ''distinct year(original_at)'' This is efficient in that it utilizes the database to do the filtering, and the code is not too ugly.

Dear R users, A co-worker and I are writing a function to facilitate graph plotting in R. The function makes use of a lot of lists in its defaults. However, we discovered that R does not necessarily preserve the defaults if we were to input them in the form of list() when initializing the function. For example, if you feed the function codes below into R: myfunction=function( list1=list

I everyone, i have a little problem with tklistbox,the " " character and Rcmdr. Please look at this code require(tcltk) tt<-tktoplevel() levels.list2 <-tklistbox(tt,selectmode="multiple",exportselection="FALSE", height=4, yscrollcommand=function(...)tkset(levels.list2.scroll,...))

I can''t see how to use variables so I am using console to test things out... clients table - a column named first_name My very brief console session... >> clients = Client.find_by_sql("select * from clients where first_name = FN") ActiveRecord::StatementInvalid: RuntimeError: ERROR C42703 Mcolumn "fn" does not exist Fparse_expr.c L1034

Hi, Algorithm question: I have two sets of "intervals", where an interval is an ordered pair [a,b] of two numbers. Is there an efficient way in R to generate the intersection of two lists of same? For concreteness: I'm representing a set of intervals with a data.frame: > list1 = as.data.frame(list(open=c(1,5), close=c(2,10))) > list1 open close 1 1 2 2 5

Hi, I have 2 questions on list object:   1. Suppose I have a matrix like: dat <- matrix(1:9,3)   Now I want to replicate this entire matrix 3 times and put entire result in a list object. Means, if "res" is the resulting list then I should have:   res[[1]]=dat, res[[2]]=dat, res[[3]]=dat   How can I do that in the easilest manner?   2. Suppose I have 2 list objects: list1 <- list2

hi, i'm trying to figure out if there's any possibility to write a whole vector into a matrix or data.frame or something like that. i don't mean transormation. Here an example: [,1] [,2] [1,] "a" "d" [2,] "b" "e" [3,] "c" "f" where e.g. a is a<-c(0,1) vector of length 2, b a vector of length 4,... (i know that

Hi R users I was wondering on how to use lapply & co when the applied function has a conditional statement and the output is a 'growing' object. See example below: list1 <- list('A','B','C') list2 <- c() myfun <- function(x,list2) { one_elem <- x cat('one_elem= ', one_elem, '\n') random <- sample(1:2,1) show(random)

Hi, This has bugged me for a bit. First question is how to keep classes with rbind, and second question is how to properly return vecotrs instead of lists after turning an rbind of lists into a data.frame list1=list(a=2, b=as.Date("20090102", format="%Y%m%d")) list2=list(a=2, b=as.Date("20090102", format="%Y%m%d")) rbind(list1, list2) #this loses the

Hello, am I using 'setIs' in the correct way in the subsequent (artifical) example? Do I have to specify explicit 'setAs' for 'list' and 'vector' or should this work automatically, since "getClass("List1")" states an explicit coerce also for these classes. I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000. Thanks for your

I am new to R, and I have been running into the following situation when I mistype a variable name in some code: > list1 <- list( a=1, b=2 ) > list2 <- list( a=1 ) > list2$b <- list1$c > list2 $a [1] 1 I would think at the point where I am trying to reference a field called "c" -- that does not exist -- in list1, there would be an error flagged. Instead, list1$c

R-helpers: Say I have two lists of arbitrary elements, e.g.: list1=list(c(1:3),"R is fun!",c(3:6)) list2=list(c(10:5),c(5:3),c(13,5),"I am so confused") I would like to produce a single new list that is composed of all combinations of the "top level" of list1 and list2, e.g.: listcombo=list(list(list1[[1]],list2[[1]]),list(list1[[1]],list2[[2]]

Hi, I am wondering whether we can apply 'cbind/rbind' on many **equivalent** list objects. For example please consider following: > list1 <- list2 <- vector("list", length=2); names(list1) <- names(list2) <- c("a", "b") > list1[[1]] <- matrix(1:25, 5) > list1[[2]] <- matrix(2:26, 5) > list2[[1]] <- 10:14 > list2[[2]] <-

I know that if I have a function that returns multiple values, I should do return(list(foo, bar)). But what do I do on the recieving end? fn <- function(x) { return(list(foo, bar)) } I know that at this point I could say values.list <- fn(x) and then access values.list[1] values.list[2] But that's hideous. I'd rather be able to say something like list(local_foo, local_bar)

I am struggling to understand the methodology here... I have a find.rhtml <%= start_form_tag :action => ''list2'', :first_name = client %> <%# render :partial => ''form'' %> <p><label for="client_first_name">First name</label><br/> <%= text_field ''client'', ''first_name''

Hi, I have two lists 1) List1- 30,000 rows and 104 columns 2) List2- a list of 14000 selected rownames  from List 1 Now, I want to extract all the 104 columns of List1  matching with the 14000 selected rownames from List2.  Psedocode will be something like this: match rownames(List2) with rownames(List1) extract selected matched 104 coloumns from (List1) strore in-> List3 So the