max

问题 I have a table with id , year and count . I want to get the MAX(count) for each id and keep the year when it happens, so I make this query: SELECT id, year, MAX(count) FROM table GROUP BY id; Unfortunately, it gives me an error: ERROR: column "table.year" must appear in the GROUP BY clause or be used in an aggregate function So I try: SELECT id, year, MAX(count) FROM table GROUP BY id, year; But then, it doesn't do MAX(count) , it just shows the table as it is. I suppose because when grouping

问题 I'm writing a codeigniter application, upon doing a query i get hit with the following fatal error. Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 262144 bytes) in /var/www/html/cryd/_zcore/core/Loader.php on line 262 I could increase the allowed memory size, but it seems that the issue could be much more graver, that if it is a memory leak, i'd just be giving php more memory to play around with. The query is not even that intensive, it just returns one row

问题 I'm writing a codeigniter application, upon doing a query i get hit with the following fatal error. Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 262144 bytes) in /var/www/html/cryd/_zcore/core/Loader.php on line 262 I could increase the allowed memory size, but it seems that the issue could be much more graver, that if it is a memory leak, i'd just be giving php more memory to play around with. The query is not even that intensive, it just returns one row

问题 ethnicity_col_names <- c("surname", "first_name", "surname.match", "white", "black", "hispanic", "asian", "other") colnames(ethnicity_sample) <- ethnicity_col_names ethnicity_sample$try <- pmax(ethnicity_sample$white, ethnicity_sample$black, ethnicity_sample$hispanic, ethnicity_sample$asian, ethnicity_sample$other) Each one of the ethnicity categories returns a % likelihood of the person belonging to that ethnicity. When I use the pmax function, it returns the highest % (in numbers). I want

问题 I'm trying to find an elegant way to find the max value in a two-dimensional array. for example for this array: [0, 0, 1, 0, 0, 1] [0, 1, 0, 2, 0, 0][0, 0, 2, 0, 0, 1][0, 1, 0, 3, 0, 0][0, 0, 0, 0, 4, 0] I would like to extract the value '4'. I thought of doing a max within max but I'm struggling in executing it. 回答1: Max of max numbers ( map(max, numbers) yields 1, 2, 2, 3, 4): >>> numbers = [0, 0, 1, 0, 0, 1], [0, 1, 0, 2, 0, 0], [0, 0, 2, 0, 0, 1], [0, 1, 0, 3, 0, 0], [0, 0, 0, 0, 4, 0] >>

问题 I'm trying to find an elegant way to find the max value in a two-dimensional array. for example for this array: [0, 0, 1, 0, 0, 1] [0, 1, 0, 2, 0, 0][0, 0, 2, 0, 0, 1][0, 1, 0, 3, 0, 0][0, 0, 0, 0, 4, 0] I would like to extract the value '4'. I thought of doing a max within max but I'm struggling in executing it. 回答1: Max of max numbers ( map(max, numbers) yields 1, 2, 2, 3, 4): >>> numbers = [0, 0, 1, 0, 0, 1], [0, 1, 0, 2, 0, 0], [0, 0, 2, 0, 0, 1], [0, 1, 0, 3, 0, 0], [0, 0, 0, 0, 4, 0] >>

问题 in my table one of column is Status and Date if suppose i want to get max(date) for each state then i can use group by of date But here my problem is i want to get max(date) for each transaction NOT FOR EACH STATUS that means, my status values like , create / modify / modify / submit / reject / modify / submit / reject / modify / submit now i want to get each transaction along with max date like - create / (only one) modify / submit / reject / (again) modify /submit / reject / modify / Submit

问题 in my table one of column is Status and Date if suppose i want to get max(date) for each state then i can use group by of date But here my problem is i want to get max(date) for each transaction NOT FOR EACH STATUS that means, my status values like , create / modify / modify / submit / reject / modify / submit / reject / modify / submit now i want to get each transaction along with max date like - create / (only one) modify / submit / reject / (again) modify /submit / reject / modify / Submit

问题 I have this question that has completely stumped me. I have to create a variable that equals Integer.MAX_VALUE... (in Java) // The answer must contain balanced parentesis public class Exercise{ public static void main(String [] arg){ [???] assert (Integer.MAX_VALUE==i); } } The challenge is that the source code cannot contain the words "Integer", "Float", "Double" or any digits (0 - 9). 回答1: Here's a succinct method: int ONE = "x".length(); int i = -ONE >>> ONE; //unsigned shift This works

问题 I would like to access to the min and max of a specific column from my dataframe but I don't have the header of the column, just its number, so I should I do using scala ? maybe something like this : val q = nextInt(ncol) //we pick a random value for a column number col = df(q) val minimum = col.min() Sorry if this sounds like a silly question but I couldn't find any info on SO about this question :/ 回答1: How about getting the column name from the metadata: val selectedColumnName = df.columns