Connecting to Databases through X++ PART -IV

Connecting to Databases through X++ PART -IV

Connection Class:

Connection class is mainly used for accessing the database in which a user has logged into AX i.e. Current Database and carry out the operations. This class is exetensively used in ReleaseUpdateDB classes, the classes used in data upgrades. This class cannot be run on client and should always be run on server. One more unique thing that I noticed is that the statements that you want to execute should be asserted first for permissions and then passed on to other method where they are executed. Create a class with following methods and set its RunOn property to Server.

class TestSQLExecuteClass
{
}

//This method tests the permissions for statement and then calls the method that will execute the statement
static void dbConnectionClass()
{
    ResultSet   rs;
    SqlStatementExecutePermission perm;
    ;

    perm = new SQLStatementExecutePermission("select * from CustTable where DATAAREAID = ‘CEU’");
    perm.assert();

    rs = TestSQLExecuteClass::statementExeQuery("select * from CustTable where DATAAREAID = ‘CEU’");

    while (rs.next())
    {
        info(rs.getString(1));
    }
    CodeAccessPermission::revertAssert();
}

//Executes the passed statement
private static ResultSet statementExeQuery(str _sql, Connection _con = null)
{
    ResultSet   resultSet;
    Statement   statement;
    ;

    try
    {
        if(!_con)
        {
            _con = new Connection();
        }

        statement = _con.createStatement();

// Do not call assert() here, do it in the caller
        // BP deviation documented
        resultSet = statement.executeQuery(_sql);
    }
    catch (Exception::Error)
    {
        throw error("@SYS99562");
    }

    return resultSet;
}

Now you can call the method in a job as shown below:

static void dbConnectionClass(Args _args)
{
    ;

    TestSQLExecuteClass::dbConnectionClass();
}

These examples shown here are pretty simple and easy to understand and start with. Hope it helps you in building ‘connections’

-Harry