Why is my promise chain not working?

Question

I am trying to sow a database using knex. With the help of a contributor, I successfully sowed one table where I need to take several steps:

• I need to derive id values ​​from several external tables so that I can populate the foreign key values ​​of the seed table.
• Create n entries in the seed table.
• Fill the table.

As already mentioned, this works for me for one table. Since I'm smarter than the roof, and I need to do almost the same thing for another table, I just copied what worked in the first seed file, fell into the second seed file, made a couple of suitable modifications (in particular, in the second table I need just fill in 1 value of the foreign key) and ... this will not work.

I'm at a loss. Surely there is some kind of stupid thing that I miss in this code, but I can not find it. I am trying to sow a table unitsthat I have to populate with a value properties.id.

exports.seed = function(knex, Promise) {
    console.log('Seeding the %s table...', tableName);

    Promise.resolve([
        'properties',
    ])
    .map(function(table) {
        // Pull foreign key values (property_id)
        var ids = knex.select('id').from(table).pluck('id');

        // AT THIS POINT THE ids VARIABLE HAS A VALUE

        return ids;
    })
    .spread(function(properties) {
        // BUT I NEVER SEE THIS LOG PRINT
        console.log('SPREADING UNITS');
    });
};

What am I doing wrong? I dropped .catch()and .error()in this thing, but nothing is logged. Somehow, I never give up on a method .spread(...).

UPDATE

Whatever it costs, this is the contents of the method .mapuntil it returns ...

{ client:
   { Formatter: { [Function: Formatter_MySQL] super_: [Function: Formatter] },
     Raw: { [Function: Raw_MySQL] super_: [Object] },
     Transaction: { [Function: Transaction_MySQL] super_: [Object] },
     QueryBuilder: { [Function: QueryBuilder_MySQL] super_: [Object] },
     QueryCompiler: { [Function: QueryCompiler_MySQL] super_: [Function: QueryCompiler] },
     migrationConfig: { tableName: 'knex_migration', directory: './migrations' },
     seedConfig: { directory: './seeds' },
     Runner: { [Function: Runner_MySQL] super_: [Function: Runner] },
     connectionSettings:
      { host: '127.0.0.1',
        port: '3306',
        user: 'root',
        password: '',
        database: 'realster',
        timezone: 'UTC',
        charset: 'utf8',
        debug: false },
     Pool: { [Function: Pool_MySQL] super_: [Function: Pool] },
     databaseName: 'realster',
     pool: { client: [Circular], config: [Object], genericPool: [Object] },
     _events: { start: [Function], query: [Function] },
     Seeder: { [Function: Seeder_MySQL] super_: [Function: Seeder] } },
  _single: { table: 'properties', pluck: 'id' },
  _statements:
   [ { grouping: 'columns', value: [Object] },
     { grouping: 'columns', type: 'pluck', value: 'id' } ],
  _errors: [],
  _joinFlag: 'inner',
  _boolFlag: 'and',
  _notFlag: false,
  and: [Circular],
  _method: 'pluck' }

Answer 1

You use spreadwhich is the method Promise, as a result map.

mapprobably creates an array that has no function spread().

, spread . , then.

, , :

var mapProperties = function(table) {
  return knex.select('id').from(table).pluck('id');
};

Promise.resolve([
  'properties'
])
.then(mapProperties)
.then(function(properties) {
  console.log(properties);
});