How to remove all duplicates from an array of objects?

How about with some es6 magic? Reference URL A more generic solution would be: Using the above property strategy instead of JSON.stringify: You can add a wrapper if you want the propNames property to be either an array or a value: allowing both getUniqueItemsByProperties(‘a’) and getUniqueItemsByProperties([‘a’]); Stackblitz Example Explanation Start by understanding the two methods used: filter, findIndex Next take your idea of what … Read more

Remove duplicate rows in MySQL

A really easy way to do this is to add a UNIQUE index on the 3 columns. When you write the ALTER statement, include the IGNORE keyword. Like so: This will drop all the duplicate rows. As an added benefit, future INSERTs that are duplicates will error out. As always, you may want to take a backup before running something like this…

How do I find the duplicates in a list and create another list with them?

To remove duplicates use set(a). To print duplicates, something like: Note that Counter is not particularly efficient (timings) and probably overkill here. set will perform better. This code computes a list of unique elements in the source order: or, more concisely: I don’t recommend the latter style, because it is not obvious what not seen.add(x) is doing (the set add() method always returns None, hence … Read more