1 var pg = require(‘./pg‘); //加载模块 
 2 var conString = "postgres://postgres:postgres@localhost:5432/node-test";//此时数据库必须已经创建
 3                 //anything://user:password@host:port/database
 4 var client = new pg.Client(conString);
 5 
 6 client.connect(function(err) {
 7     if(err) {
 8         return console.error(‘could not connect to postgres‘, err);
 9     }
10      
11     //删除存在表
12     console.log("Dropping table ‘person‘")
13     var query = client.query("drop table if exists person");
14     query.on(‘end‘, function() {
15         console.log("Dropped!");
16     });
17      
18     //创建表
19     console.log("Creating table ‘person‘");
20     query = client.query("create table person(id serial, username varchar(10), password varchar(10), age integer)");
21     query.on(‘end‘, function(){
22         console.log("Created!");
23      }); 
24     
25     //添加
26     client.query(‘INSERT INTO person(username, password, age) VALUES($1, $2, $3)‘, ["zhangsan", "123456", 20], function(err, result) {
27     console.log( "====================add========================");
28     if(err) {
29         console.log(err); 
30         return rollback(client);
31     }
32         console.log( result);
33     }); 
34 
35 
36     //查询
37     client.query(‘select username, password, age from person where id = $1‘, [3], function(err, result) {
38     console.log( "===================query=========================");
39     if(err) {
40         console.log(err);  
41     }
42         console.log(result.rows[0]);
43     });
44 
45     //更新
46     client.query(‘update person set password=$1 where id = $2‘, ["11a",1], function(err, result) {
47     console.log( "=====================update=======================");
48     if(err) {
49         console.log(err);  
50     }
51         console.log(result);
52     });
53 
54     //删除
55     client.query(‘delete from person where id = $1‘, [1], function(err, result) {
56     console.log( "====================remove=======================");
57     if(err) {
58         console.log(err);  
59     }
60         console.log(result);
61         client.end();
62     });
63     
64 });
65  
66  var rollback = function(client) { 
67   client.query(‘ROLLBACK‘, function() {
68     client.end();
69   });
70 };