https://github.com/lucasdota/jdbc_transactions

Exercício em Java para treinar como executar transações de forma responsável para o mySQL com setAutoCommit() e rollback().
https://github.com/lucasdota/jdbc_transactions

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Exercício em Java para treinar como executar transações de forma responsável para o mySQL com setAutoCommit() e rollback().

• Host: GitHub
• URL: https://github.com/lucasdota/jdbc_transactions
• Owner: Lucasdota
• Created: 2024-10-17T14:06:44.000Z (4 months ago)
• Default Branch: master
• Last Pushed: 2024-10-17T14:08:02.000Z (4 months ago)
• Last Synced: 2024-10-19T20:14:53.507Z (4 months ago)
• Language: Java
• Size: 4.88 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
## Exercício em Java para treinar como executar transações de forma responsável para o mySQL com setAutoCommit() e rollback().

### Programa principal:

```java

package application;

import java.sql.Connection;

import java.sql.SQLException;

import java.sql.Statement;

import db.DB;

import db.DbException;

public class Program {

	public static void main(String[] args) {

	

		Connection conn = null;

		Statement st = null;

		

		try {

			conn = DB.getConnection();

			

			// we need to make sure the program executes the entire code 

			// or doesnt execute not at all

			// all operation are pending waiting for a confirmation

			conn.setAutoCommit(false);

			

			st =conn.createStatement();

			

			int rows1 = st.executeUpdate("UPDATE seller SET baseSalary = 2090 WHERE DepartmentId = 1");

			

			int x = 1;

			if (x < 2) {

				throw new SQLException("Fake error");

			}

			

			int rows2 = st.executeUpdate("UPDATE seller SET baseSalary = 3090 WHERE DepartmentId = 2");

			

			// confirms that the operations are done, so it executes them all

			// so only executes the above code, it there wasn't any error along the way

			conn.commit();

			

			System.out.println("rows1 " + rows1);

			System.out.println("rows2 " + rows2);

		} catch (SQLException e) {

			try {

				// if there's an error along the way, returns the program to the first state

				conn.rollback();

				throw new DbException("Transaction rolled back! Caused by: " + e.getMessage());

			} catch (SQLException e1) {

				// rollback error

				throw new DbException("Error trying to rollback! Caused by: " + e1.getMessage());

			}

		} finally {

			DB.closeStatement(st);

			DB.closeConnection();

		}

		

	}

}

```