Most voted "null" questions
In computer programming, null is a special value for a pointer (or any other type of reference) that indicates that this pointer intentionally does not refer to an object (null pointer)
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answer340
viewsAjax request with unexpected return
I have an ajax code that makes a request in a php file, and in this php file has only one echo json_encode('test') In return comes the string "teste"NULL, always with this NULL iserido, after any…
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answer565
viewsFunction to check that all elements of a variable array are null
Suppose I have one array in which each element of this array is a variable that stores a string within it. Example: error{ [nome] : null; [sobrenome] : "sobrenome inválido"; [estado] : null; } I’d…
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answer109
viewsOpen new tab in Firefox and Edge with JS
Due to the restriction that the browser makes the scripts internal rounds, asking for confirmation using the code: window.open() found the following way to remove this permission from the user: var…
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answers211
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answers68
viewsQuery is not updating null values
I’m analyzing the data from a student database, the data is entered by the users themselves, and I can’t change the format of the tables and the database itself, just modify the values of the…
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answer140
views"null" is a value or a state in which the property is located?
When checking if a property/variable/object is null(o), are we checking its value or state? For example, if I have the object Quadrilátero with the properties LadoA and LadoB it will not be possible…
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answer172
viewsDo I get NULL from STRTOK?
Hello, I am using Strtok to split a string into words. My idea was to follow the word REMOVE deleted the next word from the text. void algorithm(node **root, char *line){ char *pch = strtok(line, "…
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answer1112
viewsSet at least one number in Edittext
My question is this:: Is there any way to prevent the click of a button if an Edittext has no number at all? I was able to limit minimum and maximum values (0 to 255), but I could not find a…
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answers244
viewsJavascript injection in Internet Explorer, returns null
I am developing an application that performs automation in internet explorer, I am using the Shdocvw to do this. My problem is I can’t get the return of an injection of Javascript public static void…
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answers57
viewsSymfony2 - Only one field has its value read, the others of this same field are NULL when submitting form
I have two related tables: material and items_budget. The table items_budget has a form that has a field that lists the name of all material in a group of checkbox, and next to each checkbox has two…
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answer44
viewsHow to Return Results with Integers and Nulls?
I’m trying to build a Query but they’re not succeeding, in my database I have 28 information with code 32, and 62 information with code 23, but there is information with null code, and I wanted to…
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answers726
viewsHow to read xls in javascript
Hello, I’m studying a little "communication" between php and javascript, I’m very beginner and I’m a few days with a problem that I can not solve, in php I’m generating an xls with data from BD…
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answer106
viewsError change password on login system with PHP SQL Server
Good afternoon, I’m having a big problem where I can’t get the password in the system. What is bugging me is that it seems that sqlsrv_fetch_array works differently from mysql_fetch_array, I have a…
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answer402
viewsCurl with Google Maps Directions API returning null
Below is the code I’m using: $arquivo = "destino.json"; $info = file_get_contents($arquivo); $lendo = json_decode($info); foreach($lendo->rotas as $campo){ echo "<b>Origem:</b>…
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answer71
viewsgetelementsbytagname returning zero
I am using the following code to read a file .xml try { File fXmlFile = new File("C:\\res\\teste.xml"); // C:/.../teste.xml DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();…
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answer56
viewsReturning the NULL value
Someone can help me, I’m making a code to insert data into a table in the database and update too, but unfortunately it’s not working, all variables are giving NULL and the very code that selects…
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answer76
viewsDoubt about Null Byte in Bcrypt PHP
Well, I learned that PHP’s Bcrypt is vulnerable to Null Byte. What are the tests I have to do to see this vulnerability, and what are the conquencias of it??
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answers3361
viewsHow to convert 0 to null (Error inserting NULL into an INT field from a variable)
I am editing this question to be more didactic for other members, since there are only publications addressing this situation outside the community en. I own a field INT property UNIQUE that may…
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answers1286
viewsWhich is faster: NULL or NOT NULL (with an empty string)?
I have a table with fields NOT NULL and they end up being empty. What’s the difference between a NULL (allows null values) and NOT NULL with an empty string ('') within?…
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answer658
viewsIs the null character 0 automatically placed at the end of the string or not because I limited the scanf?
#include <stdio.h> #include <stdlib.h> int main(void) { char nome[20]; char sobrenome[20]; char nomeSobrenome[40]; printf("Insira seu nome e…
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answer4525
viewsHow to handle Null fields in Postgresql
Hello, I need to know how to best use COALESCE to treat the null fields in my table. My problem is the following, I’m simulating 6 Stores and their respective cards, let’s assume that one or more…
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answer334
viewsCreate a new table for optional values
Do you have a problem creating a new table for fields that are not mandatory ? For example in the address table (cod_addressee, path, zip code, number, complement) where add-on is an optional field,…
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answer2339
viewsWhat is the Definition of NULL in C?
I was studying with my friend, and we are breaking our heads because we do not know what exactly the NULL function is! Because in every program that we see, NULL can serve in another way, I’m going…
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answers367
viewsReturning(Null) when displaying a String variable
The program must receive the name of a person and sex and show the data typed by the user, but when the program shows the name I typed is appearing Null instead of showing the name. #include…
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answer54
viewserror [Object Htmlinputelement]null I just started on the programming do n know q is wrong
Document summing up <input type="number" id="l"> <input type="number" id="e"> <button type="button" onclick="calcula()" id="h">calcular</button> <script> var n1 =…
nullasked 4 years, 4 months ago Brayan Rodrigues 13 -
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answer36
viewsPostgre Insert null in char(3) does not work
Below the error and the code I’m running Has two fields of this table that are defined as char(3), the field uf and the countryside ufcrm. Does anyone know how I can do this insert? SQL error:…
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answers75
viewsError with NULL values in a data frame R
Hello, I am working on building a data frame in R from a JSON that I receive after doing a GET on a service, but I am getting an error because one of the return JSON values is null, it follows part…
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answers42
viewsuseEffect returning null
I’m starting with React Native, but I’m having trouble getting a list when loading the screen using useEffect, every time you start the screen the first time, setList returns empty, and when I click…
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answer37
viewsfopen returning NULL
Good evening, I’m having a problem in fopen function within a subroutine. This returning NULL. I could not identify the error because I am still beginner, if someone can help me. Note: I declared…
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answers1948
viewsSQL - set null values to 0
I have a table pivot that returns some null values in SUM(1). I wish they were zero instead of zero, but I’m not getting it. Pivot table original SELECT Description AS Categoria, [ACS], [URO] FROM (…
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answers645
viewsSQL Server subquery is always returning null. How to fix.
I have a Procedure and a COMMON TABLE EXPRESSION(subquery). This my CTE does a search and offers to my query the result, my query then uses the results of it. In my table Address I have a field…
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answer106
viewsWhy is the description variable leaving null?
I don’t understand why the variable descricao not producing the values. In this case, it should go out like this: Old charger connecting two-pin connector socket But it’s coming off: Old charger…
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answer1368
viewsHow to find Null values without specifying attribute (Mariadb)
I would like to do a search to find NULL values across the table without having to determine which of the attributes might contain NULL. NOTE: By ALL table I mean that somewhere in it you have null,…
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answer57
viewsMy list still has Tail and head as null
It was all going well until I noticed that the list is not filled out, leaving my head and Tail as null. Supposedly the program should read from an input file and fill in the list within a cycle.…
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answer906
viewsMethod $_POST returning NULL
Good night. I’m having a problem with my $_POST method, because it only returns me NULL. I have tried from N forms, redesigned design, BD, refiz class by class, etc., but without success. Where am I…
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answer190
viewsRemove Null Item from a Combobox c#
Hello, I need to develop an advanced search filter. I created some comboBoxs for the keywords, but whenever I need to fetch the contents of a column that eventually has less content than another…
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answers153
viewsWrite null Datetime field in Access base (mdb)
Good afternoon to all. Please I need your help. I am trying to record/update a Datetime-like Birth field, but not always this field will be populated due to business rule sometimes it will be null.…
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answers276
viewsAccepting null fields from a Texbox
When I click on "Save", the program does a check of Texbox with a deal that I did not let pass repeated numbers, the problem is that it error if any Textbox is blank. Below is the Code I made saving…
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answer200
viewsSpring returning NULL in only one of the form fields
I am learning Java and am having a problem with a form using Spring. I even found a similar problem here on the forum but a little different from mine. It is a basic login page, containing only two…
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answers880
viewsEnd loop when an entry is empty
I have the following situation: A repeat loop that asks for name, and 2 notes, where the data input should end when an empty name is read, but in the way below the second time the program runs the…
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answers252
viewsReturn the row of a table when the value of Count(field) is 0 in Mysql
I need that even when the search does not generate results, is displayed the value 0, I tried with the following SQL search, but without success: SELECT c.categoria as categoria, CASE WHEN…
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answer141
viewsNull appears instead of the recovered name
When seeing the application, I see that in the variable nomedoHumano appears null, and the user’s name should appear. Just below the method Onclick, recover the name typed. I’ve thought about…
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answers37
viewsHow to show NULL in fields where the condition is not satisfied in SQL
I have this Input table (p): EmployeeID EventId EntityId EnterDate 11111 100 1 2:54:11 11111 100 1 2:54:43 11111 100 1 2:56:03 11111 100 1 2:56:35 11111 100 1 2:58:51 And this Output table (q):…
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answer259
viewsREST - Send null to Integer parameter
I have the following situation in my REST (Jersey): URL: http://localhost:8080/api/listar_log_utilizacao/null Code: @GET @Path("/listar_log_utilizacao/{idUsuario: .*}")…
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answers83
viewsSQL Identity declared (1, 1) inserting 0
I have a serious problem in my database. Some of my tables were created with Pk and Identity (1, 1) which is standard. However, when restoring the database some of these tables get PK NULL and when…
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answer289
viewsSet variable to null in a Query in php
I have the following QUERY on my system: $Query = "SELECT * FROM Monit WHERE ($Modulo IS NULL OR Modulo = '$Modulo') AND ($Usuario IS NULL OR Usuario = '$Usuario') AND ($Data IS NULL OR Data_reg =…
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answer78
viewsSafari sends $_FILE as empty (NULL) via Ajax
I have an image upload script that works normally with Chrome, EDGE, Firefox and Opera. But it doesn’t work with Safari. The Safari browser opens the windows window for me to choose an image. When…
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answer1541
viewsTo assign the value 0 to a query by returning NULL SQL
Good afternoon, I have a question regarding the treatment of values in a query. The query below to the executed returns a null value NULL as I could assign the value 0 instead of NULL? select…
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answers201
viewsReturn an "error" message if the mysql query returns empty
Guys I’m starting now in PHP, and I wanted a little help, I need a page to return a message saying that the bank is empty, but I’m not getting, here’s my code: </head> <body> <table…
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answer601
viewsNullreferenceexception: Object Reference not set to an instance of an Object (Unity)
I saved my project, I closed the Unity and after I reopened the project, to my surprise, an error was presented on the console: Nullreferenceexception: Object Reference not set to an instance of an…