duplicate-removal

问题 Afternoon/Evening all, I'm looking for the final touches to the below query. I need to remove the duplicate occurrences of a column in a particular row. Currently using the below SQL: SELECT CBNEW.* FROM CallbackNewID CBNEW INNER JOIN (SELECT IDNEW, MAX(CallbackDate) AS MaxDate FROM CallbackNewID GROUP BY IDNEW) AS groupedCBNEW ON (CBNEW.CallbackDate = groupedCBNEW.MaxDate) AND (CBNEW.IDNEW = groupedCBNEW.IDNEW); My result set looks like the below ID RecID Comp Rem Date_ IDNEW IDOLD CB?

问题 Following is the sample o/p of the SQL query - BUG_ID | LINKED_BUG_ID -----------|----------------- 3726 | 45236 45236 | 3726 3726 | 45254 45254 | 3726 3726 | 45402 45402 | 3726 3726 | 1182 1182 | 55745 In my SQL o/p, there are two rows out of which one row is redundant. e.g Bug Id 3726 and Linked Bug Id 45326 and Bug Id 45326 and Linked Bug Id 3726 are present twice in the o/p, out of which we need only one row and ignore such kind of duplicate rows (having either of a value repeated in Bug

问题 I have a string vector data containing items that I want to insert into a table named foos . It's possible that some of the elements in data already exist in the table, so I must watch out for those. The solution I'm using starts by transforming the data vector into virtual table old_and_new ; it then builds virtual table old which contains the elements which are already present in foos ; then, it constructs virtual table new with the elements which are really new. Finally, it inserts the new

问题 I have a mySQL table with duplicate entries (perhaps in some cases multiple duplicates). I have column called id, which may contain duplicate ids and one called unique id which, as the name suggest contains unique ids. Using the following SQL statement I am able to select the duplicate row SELECT id, COUNT(id) AS NumOccurrences FROM `TABLE 3` GROUP BY id HAVING ( COUNT(id) > 1 ) but how do I delete (all but one of) them? 回答1: DELETE t1 FROM test t1, test t2 WHERE t1.unique_id > t2.unique_id

问题 I was reading this question. The selected answer contains the following two algorithms. I couldn't understand why the first one's time complexity is O(ln(n)). At the worst case, if the array don't contain any duplicates it will loop n times so does the second one. Am I wrong or am I missing something? Thank you 1) A faster (in the limit) way Here's a hash based approach. You gotta pay for the autoboxing, but it's O(ln(n)) instead of O(n2). An enterprising soul would go find a primitive int

问题 I have a text box that has each item on a new line. I am trying to remove duplicates from this textBox. I can't think of anything. I tried adding each item to an array and the removing the duplicates, but it doesn't work. Are there any other options? 回答1: yourTextBox.Text = string.Join(Environment.NewLine, yourArray.Distinct()); 回答2: Building on what Anthony Pegram wrote, but without needing a separate array: yourTextBox.Text = string.Join(Environment.NewLine, yourTextBox.Lines.Distinct());

问题 I can't find appropriate way to delete duplicate keys in sql table with lowest number. If there is a duplicate rows with the same Number, I need to delete one of them. For example Key Number Description 11111 5 Desc1 11111 4 Desc2 22222 2 Desc1 22222 2 Desc2 33333 3 Desc1 33333 5 Desc2 Here I need to be deleted the second row with Number 4 which is smaller then Number 5, one of the third or fourth row, and fifth row which have smaller Number 3 then the last row 5. 回答1: Query to remove

问题 key issue: using setattr to change level names, keeps unwanted duplicates. I am cleaning some data where I have sevearl factor levels, all of which are the same, appearing as two or more distinct levels. (This error is due mostly to typos and file encoding issues) I have 153K factors, and abot 5% need to be corrected. Example In the following example, the vector has three levels, two of which need to be collapsed into one. incorrect <- factor(c("AOB", "QTX", "A_B")) # this is how the data

问题 Setup: I am creating an ms access database to record the results of experiments that will be done by myself and others. I have created a form and a subform; the main form contains fields about the equipment setup and the subform contains the experiments with that equipment setup. The link master and link child are the SettingID. Problem: Even though the fields in the main [settings] form are limited to combo-box selections, there are still numerous setting combinations. Therefore when the

问题 I am working on this famous interview question on removing duplicate elements in array without using auxillary storage and preserving the order; I have read a bunch of posts; Algorithm: efficient way to remove duplicate integers from an array, Removing Duplicates from an Array using C. They are either implemented in C (without explanation) or the Java Code provided just fails when there is consecutive duplicates such as [1,1,1,3,3] . I am not quite confident with using C , my background is