Question

I’m trying to restore a MySQL database from a file generated with mysqldump.
I do it with an ArrayList that contains each query of the restoration plan and I execute each one of them with a Statement.

But sometimes, it stops on some point of the proccess (it can be different on different executions). It doesn’t show any error message; it just hangs (when this happens, I need to restart the Mysql service).

This is the code of the restoration:

    ArrayList<String> sql;
    int res;

    FileSQLCommandManager fichero = null;
    try {
        if (pass == null)
            conectar(conn);
        else
            conectar(conn, pass);

        Statement st = null;
        st = conn.createStatement();     

        st.executeUpdate("SET FOREIGN_KEY_CHECKS=0");

        PreparedStatement stConstraints = null;

        String cadenaSQL = null;
        String cadenaSQLConstraints = null;
        String cadenaConstraints;
        ResultSet rs;
        boolean ejecutar = false;

        fichero = new FileSQLCommandManager(fic);

        fichero.open();

        sql = fichero.read();

        cadenaSQL = "";

        for (int i = 0; i < sql.size(); i++) {

            cadenaSQL = sql.get(i);
            ejecutar = true;

            if (ejecutar) {                    

                st = null;
                st = conn.createStatement();
                res = st.executeUpdate(cadenaSQL);
                if (res == Statement.EXECUTE_FAILED) {
                    System.out.println("HA FALLADO LA CONSULTA " + cadenaSQL);
                }


            }

        }
                st.executeUpdate("SET FOREIGN_KEY_CHECKS=1");
                st.close();
        fichero.close();

        commit();
        desconectar();
        fichero = null;
        return true;

    } catch (Exception ex) {
        ex.printStackTrace();
        rollback();
        desconectar();
        return false;
    }

}

FileSQLCommandManager is a class that fills the ArrayList. This works, the ArrayList content is all right. It stops on executeUpdate of any query (not always, sometimes it works without problems WITH THE SAME SQL FILE).

First I disable the foreign key checks because it can drop a table with a reference (the order of recreation of tables is set by the SQL dump).

Any hint?

Thank’s; I’m getting mad with this 🙁

Answer 1

Why are you going through all that work, when a simple mysql < db_backup.dump will restore the whole thing for you?