Paginate function not working with Postgres

[shradhaN]

We are using a node backend application with Postgres as database.

The paginate is failing method is failing in @leapfrogtechnology/db-model@1.0.0-beta.2

The model

import BaseModel from '../baseModel';
import Table from '../common/enums/table.enum';

/**
* User Model
*/
class User extends BaseModel {
 public static table: string = Table.USERS;
}

export default User;

Dao layer method call

export function fetchPaginatedUser(): Promise<any> {
  const params = {
    maxRows: 10,
    currentPage: 1,
    totalCountQuery: 'SELECT count(*) as count from users'
  }
  return User.paginate('SELECT * from users', params);
}

Expectation:

To get 10 rows of records.

Error message

  knex:client acquired connection from pool: __knexUid2 +2s
  knex:query SELECT count(*) as count from users undefined +2s
  knex:bindings [] undefined +2s
  knex:client releasing connection to pool: __knexUid2 +2ms
[ 2020-07-02T11:55:54.273Z ] - [ error ] Error: TypeError: Cannot read property 'count' of undefined

The error seems to have originated from
totalCount = totalRecords[0].count; line in paginator.ts

the output of totalRecords is in the following format for postgres:

row : { 
          count: '99'
       }

@kabirbaidhya @mesaugat @cham11ng Any suggestion on how to get it working?

[mesaugat]

@shradhaN Unfortunately, we have not tested our package with Postgres or MySQL. There might be a few of these cases lying around.

Please feel free to send a PR with the fix and we'll happily merge it. 👉 https://github.com/leapfrogtechnology/js-util/blob/%40leapfrogtechnology/db-model%401.0.0-beta.2/packages/db-model/src/utils/paginator.ts

[kabirbaidhya]

Any suggestion on how to get it working?

We have to find out. It would be great if you could do a PR. 😉