Questions tagged as 'mysql'

Tagged questions
2
answers

How to check data range?

When requesting a vehicle reservation, the system enters the expected departure and return time code (we prefer to work with fixed codes instead of schedules to facilitate scheduling). What happens is that when the reservation is made at times a...
asked by 14.12.2015 / 13:09
5
answers

How to read data from the MySQL database of an application in C #?

I have a table with 2 columns in phpmyadmin, I can connect and read one column but the other does not, it gives the following error   An unhandled exception of type 'MySql.Data.MySqlClient.MySqlException' occurred in MySql.Data.dll   Additio...
asked by 07.12.2015 / 02:30
3
answers

Change field type MySQL

I wonder if it is possible to change the data type of a column in Mysql. For example: I have a USUARIO table with the SITUACAO column, in varchar and need to change to bit . I thought about doing something like: UPDA...
asked by 08.10.2015 / 14:52
5
answers

What is the best practice to know if a row exists in a SELECT in MySQL?

For example, when we are going to check if a user is already registered in the table, we do not need any data return by the query, just check if the number of rows is greater than 0 ( num_rows > 0 ). In the scripts and frameworks...
asked by 09.07.2015 / 22:36
5
answers

In the ORDER BY of a SELECT exchange point by point

I have a table in MYSQL (you can see here link ), where the price is commas and not points: 2.33 11.00 When I will give an order by: ORDER BY preco ASC The system understands that it is a string and puts the 11.00 in front, how to do...
asked by 11.10.2016 / 21:14
3
answers

How to connect Python with Mysql?

I would like to know how I can make a simple Mysql connection through a Python script. For me to do this do I need to install some library? Or is there something that comes by default in Python (same as in PHP)?     
asked by 10.01.2017 / 19:07
1
answer

Problems with a MYSQL query - Categories and Items

I'm doing a project, which basically consists of item and category ... or rather "animes" and "episodes" ... Here's the problem, I want to list all the registered anime and a count of episodes related to them, for example. "Katekyo - 24 episo...
asked by 27.02.2015 / 17:48
2
answers

What is the performance difference between BIGINT and INT in MySQL?

Is there a negative impact on the performance of MySQL, where the Primary Key is of type BIGINT(20) , instead of INT(11) ?     
asked by 10.07.2015 / 00:51
4
answers

String Concatenation in SQL

I make a query in a table in my MySQL database that returns the following fields: usuarioId nome sobrenome idade sexo escolaridade modeloNome hora Follow the sql below: SELECT sv...
asked by 15.01.2014 / 16:13
2
answers

What is the difference between mysql-server and mysql-client?

It is said that using the apt-get install mariadb-server command would also install mariadb-cliente . I understand that the server can be said to be where the data persists, however I lack an understanding of the client ....
asked by 15.09.2017 / 15:49