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Note that the allowDiskUse: true option is optional but will help mitigate out of memory issues as this aggregation can be a memory intensive operation if your collection size is large - so i recommend to always use it. var duplicates = []; db.transactions.aggregate([ { $group: { _id: { c...

Here's a quick GIF to make the process as easy as it can be. Labels can be applied to issues and pull requests to signify priority, category, or any other information that you find useful. On GitHub, navigate to the main page of the repository. Under your repository name, click Issues or ...

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01 field-1 PIC X(80) BASED. ALLOCATE field-1 *> use field-1 FREE field-1 *> further use of field-1 will cause memory corruption

GO TO label GO TO label-1 label-2 label-3 DEPENDING ON identifier-1 GO TO label OF section GO. The last line example indicates that an ALTER statement is in play, and another part of the code will specify which actual label is the target of the jump.

Consider the dataframes left and right left = pd.DataFrame([['a', 1], ['b', 2]], list('XY'), list('AB')) left A B X a 1 Y b 2 right = pd.DataFrame([['a', 3], ['b', 4]], list('XY'), list('AC')) right A C X a 3 Y b 4 join Think of join as wanting to combine to dat...

doOnNext operator called every time when source Observable emits an item. It can be used for debugging purposes, applying some action to the emitted item, logging, etc... Observable.range(1, 3) .doOnNext(value -> System.out.println("before transform: " + value)) .map(value -&...

repeat operator allow to repeat whole sequence from source Observable. Observable.just(1, 2, 3) .repeat() .subscribe( next -> System.out.println("next: " + next), error -> System.out.println("error: " + error), () -> System.out.print...

When some programmers see this advice: "Testing strings using == is incorrect (unless the strings are interned)" their initial reaction is to intern strings so that they can use ==. (After all == is faster than calling String.equals(...), isn't it.) This is the wrong approach, from...

A closure is a procedure that holds internal state: Define a procedure that returns a closure The procedure make-an-adder takes one argument x and returns a function that closes over the value. Or to put it another way, x is within the lexical scope of the returned function. #lang racket (define...

Prepared statements See Prepared statements in MySQLi for how to prepare and execute a query. Binding of results Object-oriented style $stmt->bind_result($forename); Procedural style mysqli_stmt_bind_result($stmt, $forename); The problem with using bind_result is that it requires the s...

INITIATE report-1 report-2

One of the most important implementations of Dynamic Programming is finding out the Longest Common Subsequence. Let's define some of the basic terminologies first. Subsequence: A subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the orde...

GCobol identification division. program-id. inspecting. data division. working-storage section. 01 ORIGINAL pic XXXX/XX/XXBXX/XX/XXXXXXX/XX. 01 DATEREC pic XXXX/XX/XXBXX/XX/XXXXXXX/XX. procedure division. move fun...

Before reading this example, it is highly recommended that you read Introduction to Trie first. One of the easiest ways of implementing Trie is using linked list. Node: The nodes will consist of: Variable for End-Mark. Pointer Array to the next Node. The End-Mark variable will simply denot...

GCobol >>SOURCE FORMAT IS FIXED *> *************************************************************** *> Purpose: Demonstrate a merge pass *> Tectonics: cobc -x gnucobol-merge-sample.cob *> *************************************************************** ...

From Odata.org OData (Open Data Protocol) is an OASIS standard that defines the best practice for building and consuming RESTful APIs. OData helps you focus on your business logic while building RESTful APIs without having to worry about the approaches to define request and response headers, ...

Regular expression support for tust is provided by the regex crate, add it to your Cargo.toml: [dependencies] regex = "0.1" The main interface of the regex crate is regex::Regex: extern crate regex; use regex::Regex; fn main() { //"r" stands for "raw" str...

Before reading this example, it is required to have a brief idea on edge-relaxation. You can learn it from here Bellman-Ford Algorithm is computes the shortest paths from a single source vertex to all of the other vertices in a weighted digraph. Even though it is slower than Dijkstra's Algorithm, i...

In case of problems, enable the internal logger. C# example: // set internal log level InternalLogger.LogLevel = LogLevel.Trace; // enable one of the targets: file, console, logwriter: // enable internal logging to a file (absolute or relative path. Don't use layout renderers) InternalL...