unique

问题 I have two tables in my system EMPLOYEE and EMPLOYEE_FORECAST . Both have the same columns, entire structure is same. I have another archive table with same structure called EMPLOYEE_ARCHIVE table. I need to put data from both tables to this archive table. Since records in EMPLOYEE and EMPLOYEE_FORECAST may have same primary key e.g. a record in EMPLOYEE will have a pk of say 100 and another record in EMPLOYEE_FORECAST may also have pk of 100 and this will definitely happen so when they are

问题 This question already has answers here : Perl reading file, printing unique value from a column (3 answers) Closed 5 years ago . i have a file that has the following data: col1 col2 ext3 rw col1 col2 ext3 rw col1 col2 ext3 rw col1 col2 nfs rw col1 col2 ext4 rw col1 col2 iso9660 ro what am trying to do is to read the file and print unique values from column 3. The column 3 contains the ext3,ext4,nfs ... currently my output is: ext3 ext3 ext3 nfs ext4 iso9660 and my output should be : ext3 nfs

问题 I am currently in the process of writing a mobile app with the help of phonegap. One of the few features that I would like this app to have is the ability to capture an image and upload it to a remote server... I currently have the image capturing and uploading/emailing portion working fine with a compiled apk... but in my php, I am currently naming the images "image[insert random number from 10 to 20]... The problem here is that the numbers can be repeated and the images can be overwritten..

问题 How to effectively select pandas dataframe columns which have only 1 unique value? I'm aware of DataFrame and Series.nunique() 回答1: I think need DataFrame.nunique for boolean mask and select by loc with boolean indexing: df = pd.DataFrame({'A':list('abcdef'), 'B':[4,5,4,5,5,4], 'C':[7,8,9,4,2,3], 'D':[1] * 6, 'E':[5,3,6,9,2,4], 'F':list('aaaaaa')}) print (df) A B C D E F 0 a 4 7 1 5 a 1 b 5 8 1 3 a 2 c 4 9 1 6 a 3 d 5 4 1 9 a 4 e 5 2 1 2 a 5 f 4 3 1 4 a df = df.loc[:, df.nunique() == 1]

问题 I have two vectors g and h . I want to compare the numbers in these two vectors and find out whether there are any common elements between them. But the common elements do not have to be exactly the same and can be within a range of (-0.5, +0.5) . Therefore, g±0.5 is being compared with h±0.5 . g <- c(0.5, 5956.3, 38, 22.666, 590.3, 21.992, 9.3) h <- c(0.7, 99.2, 39, 30, 21.68, 9.4, 22.333, 0.001, 0.000222, 9.999) As an example, in the two vectors above, 0.5 from g and 0.7 from h match

问题 I have a data structure, where I have to store pairs of elements. Each pair has exactly 2 values in it, so we are employing a table, with the fields(leftvalue, rightvalue....). These pairs should be unique, and they are considered the same, if the keys are changed. Example: (Fruit, Apple) is the same as (Apple, Fruit). If it is possible in an efficient way, I would put a database constraint on the fields, but not at any cost - performance is more important. We are using MSSQL server 2008

问题 I have a data structure, where I have to store pairs of elements. Each pair has exactly 2 values in it, so we are employing a table, with the fields(leftvalue, rightvalue....). These pairs should be unique, and they are considered the same, if the keys are changed. Example: (Fruit, Apple) is the same as (Apple, Fruit). If it is possible in an efficient way, I would put a database constraint on the fields, but not at any cost - performance is more important. We are using MSSQL server 2008

问题 I have a data structure, where I have to store pairs of elements. Each pair has exactly 2 values in it, so we are employing a table, with the fields(leftvalue, rightvalue....). These pairs should be unique, and they are considered the same, if the keys are changed. Example: (Fruit, Apple) is the same as (Apple, Fruit). If it is possible in an efficient way, I would put a database constraint on the fields, but not at any cost - performance is more important. We are using MSSQL server 2008

问题 I have 2 arrays as below. $keys = [1,2,3,4-1,99,1,2,3,4-1,4-2,4-3,99,1,2,3,4-1,4-2,99] $values = [a,b,c,d,x,a1,b1,c1,d1,e,g,x,a2,b2,c2,d2,e,x] I want to combine into an array like: $result = array( [0]=>array(1=>a,2=>b,3=>c,4-1=>d,99=>x), [1]=>array(1=>a1,2=>b1,3=>c1,4-1=>d1,4-2=>e,4-3=>g,99=>x), [2]=>array(1=>a2,2=>b2,3=>c2,4-1=>d2,4-2=>e,99=>x ); The rule is break anytime $key=99. Currently, I tried to use array_chunk but the syntax only allows me to chunk the array by the number of unique

问题 is there any way to specify which array item to keep based on a key being non-empty. it seems uniq just keeps the first occurrence. e.g: var fruits = [ {'fruit': 'apples', 'location': '', 'quality': 'bad'}, {'fruit': 'apples', 'location': 'kitchen', 'quality': 'good'}, {'fruit': 'pears', 'location': 'kitchen', 'quality': 'excellent'}, {'fruit': 'oranges', 'location': 'kitchen', 'quality': ''} ]; console.log(_.uniq(fruits, 'fruit')); /* output is: Object { fruit="apples", quality="bad",