Java project with Oracle and Mysql at the same time?

Question

In view of an Oracle BD and a Mysql BD, and the impossibility of integration of both bases:

It would be possible, for example, a class of my application to 'look' at the mysql table and update an oracle table?

Answer 1

By searching you can open two connections with different databases and then insert the read data from one database into the other more or less like this:

String urlMySql = "jdbc:mysql://localhost:3306/seu_database_mysql";
String urlDb2 = "jdbc:db2://localhost:50000/seu_database_db2";

Connection connMySql = DriverManager.getConnection(urlMySql);
Connection connDb2 = DriverManager.getConnection(urlDb2);

PreparedStatement selectDb2 = connDb2.prepareStatement("SELECT * FROM TABELA");
ResultSet rsDb2 = selectDb2.executeQuery();

while (rsDb2.next()) {
 PreparedStatement insertMySql = connMySql.prepareStatement("INSERT INTO OUTRA_TABELA VALUES...");
insertMySql.setXXX(rsDb2.getXXX(...));
insertMySql.executeUpdate();
}

Hence, all you have to do is manage Connections, Preparedstatements and Resultsets as usual (including by closing them in a Finally block or using Try-with-Resources).

It is also valid to encapsulate the Connections in Daos, put the connections in pools or separate any operation with the database in several classes and/or various methods. Just keep in mind that there may be more than one connection to the active database at the same time (along with the respective Preparedstatements and Resultsets).