Query parameters handling causes syntax error

When I do the following query, everything completes fine in psql:

-- psql
INSERT INTO public.contest (contest_id, period_id, start_ts, end_ts, contest_name, default_format, status ) 
VALUES ('VKVPA', '2019/01', timestamp '2019-01-20 08:00', 
timestamp '2019-01-20 11:00', 'description', 'EDI', 'NEW' ) RETURNING contest_key;

-- console output:
contest_key |
------------+
         17 |

(start_ts and end_ts have type TIMESTAMP WITHOUT TIME ZONE) When I do the same in a program using pg module, it ends with syntax error:

// contest-debug.ts
import { Pool } from 'pg' ;
let pool = new Pool( {user: 'contest_owner', database: 'contest'} );
pool.query(
    "INSERT INTO public.contest (contest_id, period_id, start_ts, end_ts, contest_name, default_format, status ) "
    + "VALUES ($1, $2, timestamp $3, timestamp $4, $5, $6, 'NEW' ) RETURNING contest_key", 
    ['VKVPA', '2019/02',  '2019-02-17 08:00', '2019-02-17 11:00', 'VKV Provozni aktiv 2019/02', 'EDI']
  )
  .then( result => { 
      console.log(`New contest has number ${result.rows[0].contest_key}`);
    })
  .catch( reason => { console.log( 'Contest creation failed:', reason )});

Console output:

Contest creation failed: { error: syntax error at or near "$3"
    at Connection.parseE (D:\dev\cav\log2any\node_modules\pg\lib\connection.js:601:11)
    at Connection.parseMessage (D:\dev\cav\log2any\node_modules\pg\lib\connection.js:398:19)
    at Socket.<anonymous> (D:\dev\cav\log2any\node_modules\pg\lib\connection.js:120:22)
    at Socket.emit (events.js:193:13)
    at addChunk (_stream_readable.js:296:12)
    at readableAddChunk (_stream_readable.js:277:11)
    at Socket.Readable.push (_stream_readable.js:232:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:150:17)
  name: 'error',
  length: 92,
  severity: 'ERROR',
  code: '42601',
  detail: undefined,
  hint: undefined,
  position: '135',
  internalPosition: undefined,
  internalQuery: undefined,
  where: undefined,
  schema: undefined,
  table: undefined,
  column: undefined,
  dataType: undefined,
  constraint: undefined,
  file: 'scan.l',
  line: '1134',
  routine: 'scanner_yyerror' }

The following code works. I did not pass the timestamp strings as parameters and instead included them directly in the text of the query. Apparently, this is a bug either in libpq or in the javascript module. For some strange reason a string parameter is not handled as string if it is preceded by timestamp keyword in the query,

pool.query(
    "INSERT INTO public.contest (contest_id, period_id, start_ts, end_ts, contest_name, default_format, status ) "
    + "VALUES ($1, $2, timestamp '2019-02-17 08:00', timestamp '2019-02-17 11:00', $3, $4, 'NEW' ) RETURNING contest_key", 
    ['VKVPA', '2019/02',  'VKV Provozni aktiv 2019/02', 'EDI']
  )
...

[sehrope]

It’s not possible to specify parameter values for the literal portion of SQL standard TIMESTAMP '...' literals. It’s not specific to this driver or libpq, it’s a server limitation that you can’t specify a parameter when using that particular syntax.

As a workaround you can use the PostgreSQL specific casting syntax: $3::timestamp

Also, you may want to look into using timestamptz rather than timestamp (with no tz).

[radio-miskovice]

BTW, where could I find the syntax note? I was reading through sections 8.5 and 9.9 and contrary to what is needed in the code, they only mention the syntax that maybe works fine in psql only, i,e, TIMESTAMP followed by a ISO-8601 string. It’s kind of confusing. I will post a correction request in the doc section. Actually in standard SQL it would be CAST( $3 AS TIMESTAMP ) which works perfectly well but who knows why they do not even mention it in the manual (section 8.5 and 9.9).