Most voted "database" questions
A database (its abbreviation is BD, DB, database) is an organized collection of data typically used to model certain situations. Use this tag if you have questions about designing a database. If this is a specific database management system, like Mysql, for example, use this tag instead.
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answer128
viewsRecover city from database id
I’m getting information from a select, which pulls the states and cities registered in the database. In the value of each select (city and state) is their id in the table (only this way to work with…
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answer1658
viewsRemove the last value found inside a string
I need to take an average of payment conditions in the database and I came across the situation where the condition column is a string and it can receive parcel values separated by bar. I need to…
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answer22
viewsSearch for information not directly related in the Database
I would like to select from a database that has the tables Book, Author and Publisher, the attributes Author name, Last name, Book title and Publisher of tables that are not directly related (so to…
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answer84
viewsError in database connection
Good morning! I have a panel in php and the same is not connecting to DB. Any password I enter, password or incorrect user. Follow the code snippet that makes the connection: <?php…
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answer210
viewsHow to change the location of the database
I’m creating a database like the SqlOpenHelper and I know that it saves the database in the folder date. I was wondering if there’s a way to move the location of the database to the sdcard for…
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answers173
viewsBest Way to Store Varchar(MAX)
I’m working on an EAD project where I work. There will be simulations with many questions and their respective answers. These questions and some answers are usually quite large and I am storing them…
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answer44
viewsError when relating two tables in the database
I’m with a web project in java, in which I’m mapping towers and patchpanels, where a tower has several patchs and a patch has only one tower attached to it. This relationship is all ok, now the…
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answer54
viewsMigration from Local BD to Mysql BD
I am working on an ASP.NET WEB page with MVC and I have made all model, control and display settings in Visual Studio 2017 and the same created a Local BD by SQL Server Localdb to store the data but…
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answers1947
viewsAdd time column in SQL SERVER
I got a column like team in a table. With records such as: 00:02:15 00:09:47 00:00:25 ... I need in mine select, find the sum of those minutes in format team. Return example: 00:12:27 I tried in…
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answers2415
viewsSQL query that compares two tables and returns values
Work with a database using with DBMS Postgresql, where I need to compare tables, example: table_janeiro and table_February. I need to perform two consultations... first You must return the values…
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answer367
viewsAttempt to invoke virtual method 'void
Good evening, I am not able to solve the problem, it says it has an unregistered object (null Object Reference), but it does not have to initialize the following code: public void deletar(int id) {…
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answer417
viewsTransfer fields from one table to another
Good morning, is there any way to transfer the fields to more than one table? I have an outdated database and need to create the new fields in several tables. Is there any query that does this, use…
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answers1605
viewsCalculate column date - 6 months of current date (SQL SERVER)
I have a column in db that is D_EMISSAO and in it has a date yyyyddmm. I have to show the data that are related to column D_EMISSAO if it does not exceed 6 months according to the date D_EMISSAO…
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answer685
viewsRegistration without duplicity in Sqlite
I was able to avoid the double record of romaneio(nr_roman), but I made several attempts to do the same with the plaqueta(plaq),so that if the platelet already exists in the database, it persists in…
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answers256
viewsFirebird sql error and doubts
I own this table code CREATE TABLE news ( id_news INTEGER NOT NULL, title VARCHAR(128) NOT NULL, slug VARCHAR(128) NOT NULL, text TEXT NOT NULL, PRIMARY KEY (id_news), KEY slug (slug) ); That is…
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answers50
viewsHide registration to the user
When "delete" an accurate record hides it from a table, in the user view, but it must remain in the database. I put a field called 'status' on the table that manages just that. In the exhibition I…
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answers350
viewsI cannot display an image that is saved in the BLOB database
I saved an image in the BD in a field type BLOB but when displaying it does not display the image, instead it leaves the screen black with a white square in the middle follows the code: <?php…
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answer72
viewsPassing values through variable does not work
I’m using the MDL(google) framework to make a registration system, and in the part of changing the information in the database, in passing the values through the url, only some are passed and others…
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answer102
viewsIonic Framework - Web service or Mysql
An application with Ionic Framework, can access a mysql database equal to a conventional web application? example to Hostnet. Or is a web service necessary? And in the matter of security, which one…
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answer80
viewsHow to put a successful Alert into a data insertion via ajax?
I am working on a project in progress and what I need to do on it is put an Alert and refresh the page after entering data in the database. The data are being entered through a spreadsheet, that is,…
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answers174
viewsAngular scroll with problem loading BD data
I am trying to implement Infinite Scroll to my project and following some lessons I found on the internet I reached this code: <?php $query = "SELECT * FROM produtos ORDER BY id DESC"; $resultado…
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answers37
viewsAndroid app integrated with html site with database
I need help on a matter. My TCC consists of a didactic application, which receives all its content (Text and images) through an HTML site. Is it possible for all this to work through the FIREBASE…
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answers3185
viewsHow to connect my android application to an external database
I have a site with some tables in the mysql database. The site is already connected in the database. I have an application in Android Studio and would like to connect the application with the…
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answers49
viewsSaving file on server
Good afternoon, I am trying to send a php file to the server, but it is not going to the given folder and is getting "loose" in the main folder. And also, instead of the file going to the selected…
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answers192
viewsView documents in . PDF in different folders
Good morning! I have a panel where is posted multiple PDF files, however are 3 different folders according to each file type. And in this panel, I need to put a method where the person can view the…
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answers52
viewsProblem with cyclic relationship
I have a question: I have a user who submits documents which in turn are read by other users. Is there a problem in this cycle?…
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answer725
viewsRunning time error '91' The object variable or the block variable with has not been defined
I do not know how to play very well with excel, I have to make a graph using buttons and gave this error Sub logs_acumulador() ' ' logs_acumulador Macro ' ' ActiveChart.SetSourceData Source:=Range(…
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answers465
viewsError saving Mysql PHP form information
What’s going on: I have a system that, after completing the form and saving, does not save the changes by appearing a alert "saved without changes" and back to previous page. What should happen:…
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answer90
viewsInsert column with mysql function
Good morning, I’m a beginner and I’m having a hard time. I have a column called ID and it’s a history table, so this id repeats a few times I wanted a column that returned how many times this id…
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answer1958
viewsConnection to SQL database in C#
Good morning friends, I am doubtful about database connection in particular for use in a project that captures database information for a Datagridview, my first problem is that table information is…
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answers6522
viewsDatabase, logical and conceptual model
Can help me in these logical and conceptual models, wanted to know if this right or wrong the one I did to deliver, is a car rental.…
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answer219
viewsForm does not receive registered data
What’s going on: I have a system that, after completing the form and saving, does not save the changes by appearing a alert "saved without changes" and back to previous page. It does not seem to be…
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answer346
viewsError while trying to Insert into database with Laravel
I’m using the Laravel and I’ve been racking my brain trying to figure out the cause of the following mistake while trying to make a insert: (1/1) Errorexception Illegal offset type in…
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answers5430
viewsHow is a multi-valued attribute represented?
I need to perform a modeling of Google Play as work of univerisdade, one of the requirements of the work is to represent a multivariate. how would that be represented? Would it be a type? ex: Nome…
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answers60
viewsPhoto of a database
I have a spreadsheet that I need to place photos pulling from a database. The trigger would be the product code. When entering the product code, the photo of the product would go up to the…
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answers207
viewsDisplay data from an ID in the table in a textbox - C#
I need to make one select in the database to capture the id of the last product registration, I will make an increment and show it in a textbox on my registration form. My intention is to show the…
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answers551
viewsWhat is capped Collection?
Hello, I would like to know what is Limited Collection (Capped Collection) and for what we use in Mongodb.
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answers49
viewsSend information from a Viwer Data grid to sql database
I’m putting together an order form using c#. The problem is that when I try to send the products that are listed in the Data Grid Viewer to the database, the program reads only the line where the…
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answers149
viewstransformar Y-m-d H-i-s em d-m-Y H-i-s
How do I change a date that comes from the database as Y-m-d H-i-s (2018-04-24 16:07:17) in d-m-Y H-i-s (24-04-2018 16:07:17) in php? I tried to perform this operation with the date command, but it…
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answers55
viewsHow to create triggers in BD using XAMPP?
A group has N events and each event has M spending. 1) The following Trigger should update the last modification made in the group when an INSERT is made in the event table. Why it does not work?…
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answers978
viewsForm data is not being registered
I have a form written in php with connection to a database administered by phpMyAdmin. WHAT SHOULD HAPPEN: The data entered in the form should be registered showing a alert of "successfully saved"…
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answers29
viewsIn java web development, what is the best practice for image storage? In a database or image folders?
In a Java web application, what better way to store images? Store in databases or image folders and in the database use paths to these images? And how would you do that? Thinking of using write in…
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answers76
viewsHow to use Firebird 2.1 > ABS in Firebird 2.0?
I have a client who already has a system that runs on Firebird 2.0 and my system runs on the newest version of Firebird, with this I had to regress the database and has some functions that 2.0 does…
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answer1565
viewsLaravel/Eloquent: How to create a primary key composed of two foreign keys?
I am creating a simple system for school management and I will have a table called 'class students', where the primary key should be composed by the student id and class id, which are foreign keys…
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answer80
viewsSelect data from last database file and select file data from time before last. Compare Data
After fetching two uploaded files, I go to the table to compare the data within them Amid 8: 50 e 23: 50 (with an interval of one every hour) it performs a check in a file of that bank that I call…
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answer626
viewsHow to update a field from a Database table using a Stored Procedure?
I basically have a database table, which has a field called DESCRIÇÃO and the table is called Tabela123 I have 10 records in this table, and in the DESCRIPTION field I have the sentences: Hello, you…
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answers103
viewsHow to treat the value field?
I have in my html a form, in it I have a field described this way: <option value="sao-gabriel-da-palha">São Gabriel da Palha</option> In my database I have to put the value equal to…
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answer434
viewsMany self relationship representation for many
I am creating an Entity-Relationship Model in which a Student can have many Students, thus characterizing many to many’s self-relationship. However, I am doubtful how to implement this relationship…
databaseasked 6 years, 6 months ago Lucas Dirani 197 -
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answer48
viewsComparison Datetime in scheduling in the database
I need a light. I am creating a car travel scheduling system and I need that before including a new trip, it be checked whether the date and time of the trip and the date and time of the trip were…
databaseasked 6 years, 6 months ago Mauricio Kalfelz 93 -
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answer51
viewsIs that a server error?
I have developed an application in which on my local server is working perfectly. So when I put on the web server is returning me the following error: Fatal error: Class 'mysqli' not found in Can…