1 pg = require('pg');

2 exports.pg = pg;

3

4 selector = require('../lib/selector.js');

5 exports.selector = selector;

6

7

8 // ==========================================================================

9 // Database access helper function

10 // --------------------------------------------------------------------------

11

12

13 // executes a db query and call given callback function if suceeded

14 exports.query = function (conn, req, res, query_object, callback) {

15 if (!conn || !query_object) {

16 callback(null, conn);

17 return;

18 };

19 if (typeof(conn) == 'string') {

20 // connect to database

21 conn = pg.connect(conn, function(err, conn) {

22 // TODO error handling

23 if(err) {

24 console.log(err);

25 };

26 exports.query(conn, req, res, query_object, callback);

27 });

28 return;

29 };

30 if (query_object instanceof selector.Upserter) {

31 exports.query(conn, req, res, query_object.getSelector(), function(result, conn) {

32 if (result.rows.length > 1) {

33 exports.error_handler('json', conn, req, res, "error", null, "Multiple rows found for primary key.");

34 } else if (result.rows.length == 1) {

35 exports.query(conn, req, res, query_object.getSQLUpdate(), callback);

36 } else {

37 exports.query(conn, req, res, query_object.getSQLInsert(), callback);

38 }

39

40 });

41

42 } else {

43 var query;

44

45 if (typeof(query_object) == 'string') {

46 query = { cmd: query_object, args: {} };

47 } else {

48 query = query_object.assemble(function(i) { return ('$' + (i + 1)); });

49 }

50

51 console.log(' > SQL: ', query.cmd, query.args ? query.args : '');

52

53 conn.query(query.cmd, query.args, function(err, result) {

54 if (err) {

55 console.log(err);

56 exports.error_handler('json', conn, req, res, "error", null, err.message);

57 } else {

58 callback(result, conn);

59 }

60 });

61 }

62 }