To get the database software, download and execute the Oracle installer from http://www.oracle.com/technetwork/database/enterprise-edition/downloads/index-092322.html.

The application starts from using_oracle.dart, where a JobStore object is created, the database is opened, records are written to the jobs table, and then these records are retrieved. The code from using_oracle.dart is identical to the code from using_postgresql.dart, except that we now import jobstore_oracle.dart; so please refer to the previous recipe. The jobstore_oracle.dart file contains the code to talk to the database driver:

// 1- importing the driver:
import 'package:oracledart/oracledart.dart';
import 'job.dart';

class JobStore {
  final List<Job> jobs = new List();
  Job job;
  OracleConnection conn; // connection object
  OracleResultset resultset;
  OracleStatement stmt;
  var connStr = ' "(DESCRIPTION=" "(ADDRESS=(PROTOCOL=TCP)(HOST=oracledb)(PORT=1521))"'
  '"(CONNECT_DATA=(SERVICE_NAME=XE)(SERVER=DEDICATED)))"';
  
  // 2- opening a connection to the database:
  openAndStore() {
    connect("SYS", "avalon", connStr).then((oracleconnection) {
    conn = oracleconnection;
    print('connected with Oracle!'),
    storeData();
    }).catchError(print);
  }
  
  storeData() {
  for (job in jobs) {
  insert(job);
  }
}

// 3- inserting a record in a table:
insert(Job job) {
  var jobMap = job.toMap();
  var insertSql = 'insert into jobs values (:1, :2, :3, :4, :5, :6)';
  stmt = conn.createStatement(insertSql);
  stmt.setInt(1, jobMap['dbKey']);
  stmt.setString(2, jobMap['type']);
  stmt.setInt(3, jobMap['salary']);
  stmt.setString(4, jobMap['company']);
  stmt.setString(5, jobMap['posted']);
  stmt.setString(6, jobMap['open']);
  stmt.executeQuery();
}

openAndRead() {
  connect("SYS", "avalon", connStr).then((oracleconnection) {
  conn = oracleconnection;
  readData();
  }).catchError(print);
}

// 8- reading records from a table:
readData() {
  resultset = conn.select("select * from jobs");
  processJob(resultset);
}

// 9- working with record data:
processJob(results) {
  while (resultset.next()) {
  print('dbKey: ${resultset.getInt(0)}'),
  print('type:  ${resultset.getString(1)}'),
  print('salary: ${resultset.getInt(2)}'),
  print('company:  ${resultset.getString(3)}'),
  print('posted: ${resultset.getString(4)}'),
  print('open: ${resultset.getString(5)}'),
  }
}
}

First, import the oracledart package. The connect method takes the user, his/her password, and then a connection string. In its callback, an OracleConnection object conn is made available. Querying tables is done with conn.select(selectSql), where selectSql is the selected SQL string. This returns an OracleResultset object that you can iterate throughout with next(). Values of fields can only be extracted by an index with getInt or getString.

If you need parameters in your statement, as is probably the case for insert, update, or delete statements, you first need to call conn.createStatement(sqlStr), where sqlStr contains :i indicators (i equals to ith index, starting from 0). These :i position holders must be filled with stmt.setInt(i, value) or stmt.setString(i, value). Then, the statement can be executed with stmt.executeQuery().

In this and the previous recipes, we discussed the SQL database servers that Dart can talk to at this time using specialized drivers. However, for example, for the popular Microsoft SQL Server there is no driver yet. In this case, we can use the pub odbc package by Juan Mellado (https://code.google.com/p/dart-odbc/). The ODBC binding is made with a Dart native extension, which makes it a bit more involved to be used, and for now it only exists in a 32-bit version.