Question

我是postgres的新手，并尝试做一个简单的选择查询。

我的表格如下：

create table push_table 
(
    seq_id int, 
    device_id text, 
    primary key (seq_id), 
    user_id varchar(100)
);

和我的nodejs代码如下：

pool.connect(function (err, client, done) 
  {
    if (err) console.log(err)
    myClient = client

    //query if the user exists
    var ageQuery = format('SELECT * from push_table WHERE user_id = ' + userId);
    myClient.query(ageQuery, function (err, result) {
        if (err) {
            console.log(err)
        }
        console.log("number of rows:" + result.rows.length);
    });
  });

运行nodejs服务器日志打印：

{ [error: missing FROM-clause entry for table "catherine"]
  name: 'error',
  length: 113,
  severity: 'ERROR',
  code: '42P01',
  detail: undefined,
  hint: undefined,
  position: '42',
  internalPosition: undefined,
  internalQuery: undefined,
  where: undefined,
  schema: undefined,
  table: undefined,
  column: undefined,
  dataType: undefined,
  constraint: undefined,
  file: 'parse_relation.c',
  line: '3129',
  routine: 'errorMissingRTE' }
/data/OSC_Push_OOW/releases/20170703215021/api/controllers/pushcontroller.js:58
                            console.log("number of rows:" + result.rows.length);
                                                                  ^

TypeError: Cannot read property 'rows' of undefined
    at null.callback (/data/OSC_Push_OOW/releases/20170703215021/api/controllers/pushcontroller.js:58:46)
    at Query.handleError (/data/OSC_Push_OOW/shared/node_modules/pg/lib/query.js:161:17)
    at null.<anonymous> (/data/OSC_Push_OOW/shared/node_modules/pg/lib/client.js:188:26)
    at emitOne (events.js:77:13)
    at emit (events.js:169:7)
    at Socket.<anonymous> (/data/OSC_Push_OOW/shared/node_modules/pg/lib/connection.js:133:12)
    at emitOne (events.js:77:13)
    at Socket.emit (events.js:169:7)
    at readableAddChunk (_stream_readable.js:153:18)
    at Socket.Readable.push (_stream_readable.js:111:10)

Answer 1

列user_id是varchar：

user_id varchar(100)

因此有效的SQL查询必须使用单引号来定义varchar值，例如：

SELECT * from push_table WHERE user_id = 'Vik'

您的代码不提供所需的报价。

在nodejs上选择查询postgreqs失败

1 个答案: