unique

问题 I am struggling to append a df with new variables that are computed from a subset of this df. I have two goals: Merge many individual data sets into one. The index variable is "SID" (subject ID). Create new variables/columns in this master dataset. The attached data is an example of what the already merged dataset will look like, however contains only 2 (SIDs: 9003 and 1028). I need to loop through each unique SID and perform several relatively easy computations on some of the variables in

问题 I got for example a multidimensional array items with 2 dimensions. I get this array from a database, but it will fill up to 2600+ objects, but if i could some how unique this it would be around 30 objects. How to solve this? The set up is: How i get the information: $.getJSON(url1,function(data1) { for (var i in data1.layers){ $.each(data1.layers[i].legend, function( a, b ) { for(var a in data1.layers[i].legend[a]){ $.each(data1.layers[i].legend, function( key, val ){ items.push({label: val

问题 I am trying to craft a query that will select multiple columns (uniqueID, IPaddress, date, country) but I would like the query only to select those records where the same IPaddress and UniqueID showed up on a given day. I have been trying ... SELECT uniqueID AS uniqueID, IPAddress AS IPAddr, Date AS DDate, Location AS Countries, COUNT(IPAddress) AS IPCount FROM History WHERE (uniqueID= 20677) GROUP BY Date ORDER BY DDate DESC, IPAddr DESC But it does eliminate records where only one Ip

问题 I have an Excel table in sheet1 in which column A: Name of company Company 1 Company 2 Company 3 Company 1 Company 4 Company 1 Company 3 I want to extract a unique list of company names to sheet2 also in column A. I can only do this with help of a helper column if I dont have any blanks between company names but when I do have I get one more company which is a blank. Also, I've researched but the example was for non-dynamic tables and so it doesn't work because I don't know the length of my

问题 I am trying to transform a very simple input_table into this output_table: I am basically trying to: Get unique items in first column Transpose and promote these items as column headers Get matching values (from the second column in input_table ) under each unique header I am using Power Query because I need the output_table to dynamically update each time I add records to input_table , but any other dynamical solution is accepted (Array Formulas, intermediate Tables, etc...). No VBA. 回答1:

问题 I have a system where renting companies have cars. A car can be available in many renting companies. So it is a many-to-many relationship. I want to provide the companies with the possibility to add new cars when they buy them. If the car already exists, the system wouldn't create it, but flash an error message saying they already have that car. How to use the unique validation rule on the name field of the Car being added? The challenge is that the Car model doesn't have the id of the

问题 Is there any way I can validate a value updated in a Core Data entity's property against values of the property in other entities in the collection? At the moment I create an entity with some default values, add it to arrangedObjects , then get the user to modify the various property values. However, I would like to check a particular property and make sure there're no other entities in the array with the same value for that property. What's the best way to do this? Many thanks, Dany. 回答1:

问题 Say I have a table that has a column which goes: Column B apple apple apple orange apple orange orange grapes grapes mango mango orange And I want to query it in such a way that I get a list like so: apple orange grapes mango How do I do this in PHP SQL? Much thanks. 回答1: Suppose your table is called 'Fruit' and this column is called 'B'. Here's how you would do it: SELECT DISTINCT B FROM Fruit; The 'DISTINCT' keyword will get you all unique results. That's the SQL part. In PHP, you write the

问题 I have a problem with creating unique slugs using django models. I want to allow the admin user to change the slug from the edit page in the admin. When a slug already exists there should be "slug + _1", "slug + _2" etc. Also when a new page is created and there is no slug given the slug should be the page title. I have this code but for some reason the admin keeps saying "Page with this Slug already exists." when I add a page with a slug that already exists. Hope somebody can help me def

问题 Suppose I have a data.table like this: Table: V1 V2 A B C D C A B A D C I want each row to be regarded as a set, which means that B A and A B are the same. So after the process, I want to get: V1 V2 A B C D C A In order to do that, I have to first sort the table row-by-row and then use unique to remove the duplicates. The sorting process is quite slow if I have millions of rows. So is there an easy way to remove the duplicates without sorting? 回答1: For just two columns you can use the